Detection system and detection method

Abstract

The invention provides a detection system and a detection method, the detection system is used for detecting a battery pole piece after coating and drying treatment, and the detection system comprises a pre-pressing roller device and a visual identification device arranged behind the pre-pressing roller device; the pre-pressing roller device comprises a pre-pressing roller which is rotationally arranged, the pre-pressing roller relatively abuts against the upper surface and the lower surface of the battery pole piece, the pre-pressing roller and the battery pole piece operate at the same linear speed, and the visual recognition device determines a defective area by recognizing the roughness of the battery pole piece. The detection system can effectively improve the accuracy of identifying flaws on the battery pole piece by the visual identification device, reduce the defect rate of the battery pole piece, and further ensure the quality of the battery pole piece.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a detection system and detection method. Background Technology

[0002] The production process of battery electrodes includes coating and drying. During the coating process, surface defects such as particles, scratches, dark spots, exposed foil, and bulging are easily generated. These surface defects are inspected by a visual recognition device after drying. However, once the defects are covered by the coating material, the grayscale difference between them and other normal areas on the battery electrode does not meet the resolution threshold of the visual recognition device. The surface of the battery electrode shows no difference in light reflection and scattering from the visual recognition device, causing it to fail to identify the defects. If defects exist on the battery electrode and cannot be identified, it affects the quality of the battery electrode and increases the defect rate. Summary of the Invention

[0003] The purpose of this application is to solve the aforementioned technical problems by providing a detection system and method, thereby effectively improving the accuracy of visual recognition devices in identifying defects on battery electrodes, reducing the defect rate of battery electrodes, and thus ensuring the quality of battery electrodes. To achieve the above objective, the technical solution of this application is as follows:

[0004] In a first aspect, this application provides an inspection system for inspecting battery electrodes after coating and drying processes. The inspection system includes a pre-pressing roller device and a vision recognition device disposed behind the pre-pressing roller device. The pre-pressing roller device includes a rotatably disposed pre-pressing roller that abuts against the upper and lower surfaces of the battery electrode. The pre-pressing roller and the battery electrode move at the same linear speed. The vision recognition device determines the defect area by identifying the roughness of the battery electrode.

[0005] In one possible implementation, the pre-compression roller device further includes a back roller body, which is disposed on the side of the pre-compression roller away from the battery electrode sheet, and the back roller body is abutting against and linked to the pre-compression roller.

[0006] In one possible implementation, the rotation direction of the preload roller is opposite to that of the back roller; the rotation directions of the preload rollers arranged opposite to each other are also opposite.

[0007] In one possible implementation, the back roller body includes an upper back roller and a lower back roller, and the pre-pressing roller includes an upper pressure roller and a lower pressure roller; the upper back roller and the upper pressure roller are synchronously raised and lowered, and / or the lower back roller and the lower pressure roller are synchronously raised and lowered.

[0008] In one possible implementation, the preload roller device further includes a cleaner disposed opposite to the surface of the preload roller, the cleaner being used to remove impurities from the surface of the preload roller.

[0009] In one possible implementation, a sensor is positioned in front of the pre-pressing roller device to detect the thickness of the battery electrode.

[0010] In one possible implementation, when the sensor detects that the thickness of the battery electrode is greater than a second preset value, the pre-pressure roller separates from the battery electrode to avoid the area on the battery electrode; when the sensor detects that the thickness of the battery electrode is less than or equal to the second preset value, the pre-pressure roller abuts against the battery electrode.

[0011] In one possible implementation, the detection system further includes a feed roller and a discharge roller, which are located in front of and behind the pre-compression roller device, respectively. The feed roller and the discharge roller are supported on the lower surface of the battery electrode sheet, and the straight line direction of the axis of the feed roller and the axis of the discharge roller is perpendicular to the straight line direction of the axis of the pre-compression roller that is arranged opposite to it.

[0012] Secondly, this application provides a detection method that uses the above-mentioned detection system to detect battery electrode sheets after coating and drying. The detection method includes controlling a pre-pressing roller to pre-press the battery electrode sheets to change the surface roughness of the battery electrode sheets; acquiring an image of the surface of the battery electrode sheets and identifying the surface roughness of the battery electrode sheets in the image, wherein areas with roughness greater than a first preset value are defective areas, and areas with roughness less than or equal to the first preset value are normal areas.

[0013] In one possible implementation, controlling the pre-pressing roller to pre-press the battery electrode includes obtaining the thickness parameter of the battery electrode; if the thickness parameter is less than or equal to a second preset value, controlling the pre-pressing roller to pre-press the battery electrode; if the thickness parameter is greater than the second preset value, controlling the pre-pressing roller to separate from the battery electrode.

[0014] Compared with existing technologies, the advantages of the detection system and detection method of this application are mainly reflected in:

[0015] A pre-pressing roller device is installed in the inspection system. By pre-pressing the battery electrode sheets, the surface roughness of the battery electrode sheets after coating and drying can be changed. Then, the visual recognition device accurately identifies the location of the defective area through the difference in roughness. Thus, the defects of the battery electrode sheets can be effectively identified in the current process, avoiding the impact on subsequent processes. That is, the defective area can be quickly dealt with in the current process, avoiding the problem of multiple rolls of defects. When the defect is identified in the current process, the data of defects in the current process can be accurately counted, which is conducive to targeted improvement. Attached Figure Description

[0016] Figure 1 A schematic diagram of the structure of a detection system provided for an embodiment of this application;

[0017] Figure 2 for Figure 1 The box-line diagram of the thickness distribution of the battery electrode sheets after graded rolling processing in one embodiment of the detection system shown.

[0018] Figure 3 for Figure 1 The diagram shown is a box plot illustrating the thickness distribution of the battery cell under different compression levels in one embodiment of the detection system.

[0019] Figure label:

[0020] Battery electrode 1;

[0021] 2. Pre-compression roller device; 21. Pre-compression roller; 22. Back roller body; 23. Washer;

[0022] Upper back roller 31, lower back roller 32, upper pressure roller 33, lower pressure roller 34;

[0023] Visual recognition device 41, sensor 42;

[0024] Feed roller 51, discharge roller 52, first conveyor roller 53, second conveyor roller 54. Detailed Implementation

[0025] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that the terms "S1", "S2", etc. are used only for the purpose of describing the steps, and do not specifically refer to the order or sequence, nor are they used to limit this application. They are only for the convenience of describing the method of this application, and should not be construed as indicating the order of the steps. In addition, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0026] Example 1

[0027] This embodiment provides a detection system. In the production process of battery electrode 1, the process typically includes coating, drying, and rolling. During the coating process, various defects can occur on the battery electrode 1. Except for foil exposure defects, which can still be identified by the visual recognition device 41 after coating, other types of defects cannot be effectively identified by the visual recognition device 41 after coating. Because the coating material covers the surface of the battery electrode 1, for example, if the defect is a particulate defect, the defective area appears the same as the normal area, failing to reach the resolution threshold of the visual recognition device 41. Therefore, existing methods for detecting defects in battery electrode 1 have a certain lag. Defects in battery electrode 1 already exist during the coating process, causing quality problems in multiple rolls of battery electrode 1 during the subsequent rolling process, making it impossible to accurately collect and evaluate defect data from each production line. Therefore, this embodiment uses a detection system to promptly detect defects in battery electrode 1 after the coating and drying processes, improving the defect detection rate of battery electrode 1. The following is a detailed description.

[0028] like Figure 1 As shown, the detection system includes a pre-pressing roller device 2 and a vision recognition device 41 disposed behind the pre-pressing roller device 2. The pre-pressing roller device 2 includes a pre-pressing roller 21 that is rotatably disposed. The pre-pressing roller 21 is relatively pressed against the upper and lower surfaces of the battery electrode 1. The pre-pressing roller 21 and the battery electrode 1 run at the same linear speed. If there is a defective area on the battery electrode 1, the vision recognition device 41 determines the defective area by recognizing the roughness of the battery electrode 1.

[0029] Among them, the pre-pressing roller device 2 performs pre-pressing treatment on the battery electrode 1. The two pre-pressing rollers 21 apply pressure to the upper and lower surfaces of the battery electrode 1, thereby changing the thickness of the battery electrode 1. Since there are defects on the battery electrode 1, the roughness presented by the pressure applied to the defective area is different from the roughness presented by the pressure applied to the normal area. Even if the defect is punctured by the pressure, it will not affect the difference in roughness between the defective area and the normal area.

[0030] For example, the visual recognition device 41 can be a camera module. The visual recognition device 41 can acquire images of the battery electrode 1. Since the defective area and the normal area have a roughness difference, and the roughness difference reaches the resolution threshold of the visual recognition device 41, that is, the visual recognition device 41 can identify the location of the defective area, can quickly locate the defective area, and distinguish the defective area from the normal area. The defective area can be removed by subsequent marking and unwinding rejection processes. The battery electrode 1 with the defective area removed can enter the rolling process.

[0031] A pre-pressing roller device 2 is set in the detection system. By pre-pressing the battery electrode sheet 1, the roughness of the battery electrode sheet 1 after coating and drying can be changed. Then, the visual recognition device 41 accurately identifies the location of the defect area through the roughness difference on the battery electrode sheet 1. Thus, the defects of the battery electrode sheet 1 can be effectively identified in the current process, avoiding the impact on subsequent processes. That is, the defect area can be quickly dealt with in the current process to avoid the problem of multiple roll defects. When the defect problem is identified in the current process, the data of defects in the current process can be accurately counted, which is conducive to targeted improvement.

[0032] For example, the battery electrode 1 is processed using a multi-gradient graded rolling process. In the detection system, the pre-rolling process can be considered as a first-level rolling process, and the rolling process can be considered as a second-level rolling process. The pressure of the graded rolling process of the battery electrode 1 can be relatively reduced compared to the pressure of the first-level rolling process, so as to reduce the micro-deformation of the battery electrode 1 and improve the thickness uniformity of the battery electrode 1. Figure 2 As shown, this is a box plot of the thickness distribution of battery electrode 1 after graded rolling. The horizontal axis represents the number of selected partitions on battery electrode 1, and the vertical axis represents the thickness of battery electrode 1 after graded rolling. The thickness of battery electrode 1 after graded rolling is relatively uniform, and the thickness of battery electrode 1 ranges from 149μm to 153μm.

[0033] For example, by employing multi-gradient graded rolling, the active material on the surface of the battery electrode 1 can be compacted internally, resulting in a more uniform distribution of micropores in the battery electrode 1. This more uniform internal stress distribution reduces the thickness rebound rate of the battery electrode 1, ultimately improving the thickness of the battery cell. Figure 3 As shown, this is a box plot of the thickness distribution of the battery cell under different compression amounts for battery electrode 1. The horizontal axis represents different compression amounts for battery electrode 1, and the vertical axis represents the thickness of the battery cell. After graded rolling, the battery cell exhibits good thickness consistency under different compression amounts for battery electrode 1. 100% compression amount is understood as battery electrode 1 being rolled to the target thickness in one pass. 50% compression amount = (original thickness - target thickness) * 50%. The thickness of battery electrode 1 after graded rolling is different under different compression amounts, and thus the thickness of the battery cell is different.

[0034] In one embodiment, the pre-pressing roller device 2 further includes a back roller body 22, which is disposed on the side of the pre-pressing roller 21 away from the battery electrode 1, and the back roller body 22 abuts against and is connected to the pre-pressing roller 21.

[0035] The back roller body 22 and the pre-pressing roller 21 are linked together and connected by a drive component (not shown in the figure) to achieve rotation. The back roller body 22 provides pressure to the pre-pressing roller 21, and the pressure is distributed on the entire contact surface with the pre-pressing roller 21. The back roller body 22 is used to resist the pressure of the pre-pressing roller 21, prevent the pre-pressing roller 21 from deforming due to force, and ensure that the battery electrode 1 is subjected to uniform force during the pre-pressing process. The back roller body 22 has good rigidity and reduces the radial runout of the pre-pressing roller 21 to ensure that the thickness of the battery electrode 1 is uniform after being pressed.

[0036] The main body of the preload roller 21 can be made of high-strength carbon steel or stainless steel, and the surface layer of the main body can be made of chromium or tungsten carbide, or a ceramic layer. The ceramic layer can be made of alumina, silicon carbide, or zirconium oxide, and the thickness of the ceramic layer is 1mm-200mm; or the entire preload roller 21 can be made of ceramic material. The preload roller 21 has good wear resistance, reducing surface wear after long-term use.

[0037] In one embodiment, the rotation direction of the preload roller 21 is opposite to the rotation direction of the back roller body 22; the rotation directions of the preload rollers 21 arranged opposite to each other are opposite.

[0038] The back roller body 22 includes an upper back roller 31 and a lower back roller 32, and the pre-pressing roller 21 includes an upper pressure roller 33 and a lower pressure roller 34. The rotation direction of the upper back roller 31 is opposite to the rotation direction of the upper pressure roller 33, the rotation direction of the lower back roller 32 is opposite to the rotation direction of the lower pressure roller 34, and the rotation direction of the upper pressure roller 33 is opposite to the rotation direction of the lower pressure roller 34.

[0039] like Figure 1 As shown, the conveyor belt of the battery electrode 1 travels from left to right. The left side of the conveyor belt direction is defined as the front, and the right side is defined as the rear. The upper pressure roller 33 can rotate counterclockwise, and the lower pressure roller 34 can rotate clockwise. The upper pressure roller 33 and the lower pressure roller 34 work together to press the battery electrode 1, providing friction for its movement. This ensures that the battery electrode 1 stably enters the gap between the rollers from left to right, preventing material accumulation or slippage.

[0040] The upper back roller 31 rotates clockwise, and the lower back roller 32 rotates counterclockwise. The rotation direction of the pre-pressure roller 21 is opposite to that of the back roller body 22, which counteracts the slight deformation of the back roller body 22 or the pre-pressure roller 21 caused by pressure and reduces the thickness deviation of the center and edge of the battery electrode 1.

[0041] In one embodiment, the upper back roller 31 and the upper pressure roller 33 are synchronously raised and lowered, and / or the lower back roller 32 and the lower pressure roller 34 are synchronously raised and lowered.

[0042] Since the upper back roller 31 and the upper pressure roller 33 can be connected to a common lifting device (not shown in the figure) to achieve synchronous lifting, the upper pressure roller 33 is separated from the battery electrode 1. The lifting device can be electrically driven or hydraulically driven to achieve the lifting function. Without changing the rotational speed of the upper back roller 31 and the upper pressure roller 33, the upper pressure roller 33 is separated from the battery electrode 1 by the lifting device, temporarily relieving the rolling process on the battery electrode 1 without affecting the conveyor belt movement of the battery electrode 1. The overall synchronous lifting of the upper back roller 31 and the upper pressure roller 33 makes operation more convenient for areas on the battery electrode 1 that do not require rolling. Similarly, the lower back roller 32 and the lower pressure roller 34 are set up for synchronous lifting to achieve the same effect.

[0043] In one embodiment, the upper pressure roller 33 and the lower pressure roller 34 have the same diameter, the upper back roller 31 and the lower back roller 32 have the same diameter, and the diameter of the upper back roller 31 is larger than the diameter of the upper pressure roller 33.

[0044] The existing pre-compression roller 21 is prone to bending deformation under high pressure, i.e., flexural phenomenon, which leads to the problem that the battery electrode sheet is thick in the middle and thin at the edges. Increasing the diameter of the back roller body 22 can significantly improve the bending stiffness of the pre-compression roller 21, form an effective support for the pre-compression roller 21, and reduce the flexural deformation of the pre-compression roller 21.

[0045] In one embodiment, the pre-pressing roller device 2 further includes a cleaner 23, which is disposed opposite to the surface of the pre-pressing roller 21 and is used to remove impurities from the surface of the pre-pressing roller 21.

[0046] For example, the cleaner 23 can be a laser cleaning device, which can effectively remove impurities from the surface of the pre-pressing roller 21 without burning it, and remove the impurities by negative pressure dust removal. For example, if the battery electrode 1 is a negative electrode, the material particles of the negative electrode will adhere to the surface of the pre-pressing roller 21 during the pre-pressing operation, which can be removed by the cleaner 23; or after the battery electrode 1 has been coated and dried, impurities in the production environment may fall on the battery electrode 1 and adhere to the surface of the pre-pressing roller 21, which can still be removed by the cleaner 23.

[0047] In one embodiment, a sensor 42 is provided in front of the pre-compression roller device 2, and the sensor 42 is used to detect the thickness of the battery electrode 1.

[0048] Sensor 42 can be a laser rangefinder sensor 42, capable of detecting the thickness of the battery electrode 1 in real time. Based on the thickness of the battery electrode 1, the splicing area is determined. The battery electrode 1 is carried on a strip, and the splicing area is the junction of two strips of battery electrode 1. The joints of the two strips overlap, resulting in a splicing area thickness greater than the battery electrode 1 thickness. Before the detection system pre-rolls the battery electrode 1, the location of the splicing area is determined. The splicing area can be treated the same as the defective area. The visual recognition device 41 also identifies the splicing area. In subsequent processes, the splicing area is marked and unwound for rejection. The processing of the splicing area and the defective area can be performed in the same process, eliminating the need for additional processing of the splicing area and reducing the complexity of the production line layout.

[0049] In one embodiment, when the sensor 42 detects that the thickness of the battery electrode 1 is greater than a second preset value, the pre-pressure roller 21 separates from the battery electrode 1 to avoid the area on the battery electrode 1; when the sensor 42 detects that the thickness of the battery electrode 1 is less than or equal to the second preset value, the pre-pressure roller 21 abuts against the battery electrode 1.

[0050] In this design, the pre-pressing roller 21 is separated from the battery electrode 1 and is not pre-pressed on the splice area. Since the splice area is the overlapping joint of two strips connected by adhesive, when the pre-pressing roller 21 applies a pressing force to the splice area, the strip will overflow with adhesive, causing the adhesive to adhere to the pre-pressing roller 21. The adhesive will then re-adhere to the battery electrode 1 through the pre-pressing roller 21, affecting the quality of the battery electrode 1. The second preset value is adapted to the thickness of the battery electrode 1. The thickness of the splice area is significantly greater than that of the battery electrode 1. Without changing the distance of the roller gap of the pre-pressing roller device 2, direct pre-pressing is applied to the splice area, causing overpressure on the battery electrode 1, cracking of the edge of the battery electrode 1, and risk of strip breakage. Therefore, it is necessary to separate the pre-pressing roller 21 from the battery electrode 1.

[0051] For the joint area that has not been pre-rolled by the pre-pressing roller 21, there is a difference in roughness between the joint area and the normal area. The joint area can be effectively identified by the visual recognition device 41, thereby improving the control efficiency of the joint area of ​​the battery electrode 1.

[0052] In one embodiment, the detection system further includes a feed roller 51 and a discharge roller 52, which are located in front of and behind the pre-compression roller device 2, respectively. The feed roller 51 and the discharge roller 52 are supported on the lower surface of the battery electrode sheet 1, and the straight line direction of the axis of the feed roller 51 and the axis of the discharge roller 52 is perpendicular to the straight line direction of the axis of the pre-compression roller 21 that is arranged opposite to it.

[0053] Among them, the feed roller 51, the discharge roller 52 and the lower pressure roller 34 can be located in the same horizontal direction, and the lower pressure roller 34 and the upper pressure roller 33 can be located in the same vertical direction. The lower pressure roller 34 and the upper pressure roller 33 can work together to roll and press the battery electrode 1. The upper pressure roller 33 and the lower pressure roller 34 should minimize the contact angle with the battery electrode 1 to reduce the risk of wrinkling of the electrode tabs on the battery electrode 1 after pre-rolling treatment.

[0054] For example, a first conveyor roller 53 can be provided in front of the feed roller 51, and a second conveyor roller 54 can be provided behind the discharge roller 52. The material strip of the battery electrode 1 can be passed through the lower edge of the first conveyor roller 53 and the lower edge of the second conveyor roller 54 respectively, that is, the material strip makes contact with the corner of the first conveyor roller 53 and the second conveyor roller 54 respectively. The first conveyor roller 53 and the second conveyor roller 54 effectively guide the material strip to move, thereby realizing the smooth conveying of the battery electrode 1.

[0055] Example 2

[0056] This embodiment provides a detection method, which uses the above-described detection system to detect the battery electrode 1 after coating and drying. The detection method includes:

[0057] S1. Control the pre-rolling process to pre-roll the battery electrode 1 to change the surface roughness of the battery electrode 1.

[0058] S11. Control the pre-rolling to pre-roll the battery electrode 1, specifically including obtaining the thickness parameter of the battery electrode 1. If the thickness parameter is less than or equal to the second preset value, control the pre-rolling to pre-roll the battery electrode 1. If the thickness parameter is greater than the second preset value, control the pre-rolling roller 21 to separate from the battery electrode 1.

[0059] The thickness parameter of the battery electrode 1 can be obtained by sensor 42. The battery electrode 1 has a bonding area. If the thickness parameter is greater than a second preset value, the pre-pressing roller 21 is controlled to separate from the battery electrode 1. The pre-pressing roller 21 does not perform pre-pressing treatment on the bonding area to avoid over-pressing the bonding area. The second preset value is adapted to the thickness of the battery electrode 1. If the second preset value is greater than the thickness of the battery electrode 1, it indicates that there is a bonding area on the battery electrode 1. When the pre-pressing roller 21 separates from the battery electrode 1, there is a significant roughness change between the unpre-pressed battery electrode 1 and the pre-pressed battery electrode 1. The bonding area can be identified by the subsequent visual recognition device 41.

[0060] S2. Acquire an image of the surface of the battery electrode 1 and identify the roughness of the surface of the battery electrode 1 in the image. Areas with roughness greater than a first preset value are defective areas; areas with roughness less than or equal to the first preset value are normal areas.

[0061] The first preset value is adapted to the roughness of the normal area on the battery electrode 1 after pre-rolling. The image of the surface of the battery electrode 1 can be obtained by the visual recognition device 41. After pre-rolling, the battery electrode 1 can identify the defective area and the normal area based on the difference in roughness, and can also identify the bonding area, so as to accurately determine the defective area and the bonding area on the battery electrode 1.

[0062] S3. Obtain the position parameters of the defective area and the bonding area on the battery electrode 1, and mark the defective area and the bonding area.

[0063] The marking process can be achieved by a marking device (not shown in the figure), which can be a laser marking device or an inkjet printer. The marking device leaves a mark on the battery electrode 1. After the battery electrode 1 is detected by the visual recognition device 41, the position parameters of the defect area and the bonding area can be obtained. The marking device accurately locates the defect area and the bonding area, and the defect area and the bonding area after marking can be judged intuitively.

[0064] S4. Cut the battery electrode 1 according to the marking process, and then roll it.

[0065] After pre-rolling, the internal stress of the battery electrode 1 is uniform. After another roll forming process, the thickness rebound rate of the battery electrode 1 is reduced, and the thickness uniformity of the battery electrode 1 is improved.

[0066] In this embodiment, the battery electrode 1, which has undergone pre-rolling treatment or has areas with bonding but has not undergone pre-rolling treatment, has its surface grayscale value changed after coating and drying to reach the resolution threshold that the visual recognition device 41 can recognize. This allows the detection of defective areas and bonding areas in the battery electrode 1. Defects include dark spots, white spots, scratches, exposed foil, dry material, adhesive material, and foreign object damage. During the coating and drying process, defects and bonding issues can be quickly addressed and resolved, avoiding the generation of multiple rolls of defects that could affect subsequent processes. Once defects are identified during the coating and drying process, the defect data of the battery electrode 1 can be accurately statistically analyzed through marking.

[0067] In the description of this application, unless otherwise stated, directional terms such as "up" and "down" generally refer to the relative "up" and "down" of the corresponding components in the direction of gravity when they are in use. Directional terms such as "left" and "right" refer to the positions of the corresponding components in the illustrations.

[0068] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In this application, unless otherwise expressly specified and limited, the terms "connection" and "abutment" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral part; they may refer to a direct connection or an indirect connection through intermediate components; they may refer to direct abutment or indirect abutment. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0069] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0070] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A detection system for detecting battery electrode sheets (1) after coating and drying treatment, characterized in that: The detection system includes a pre-pressing roller device (2) and a visual recognition device (41) disposed behind the pre-pressing roller device (2); The pre-pressing roller device (2) includes a rotatably mounted pre-pressing roller (21) that abuts against the upper and lower surfaces of the battery electrode (1). The pre-pressing roller (21) and the battery electrode (1) run at the same linear speed. The visual recognition device (41) determines the defect area by recognizing the roughness of the battery electrode (1).

2. The detection system according to claim 1, characterized in that: The pre-pressing roller device (2) further includes a back roller body (22), which is disposed on the side of the pre-pressing roller (21) away from the battery electrode (1). The back roller body (22) abuts against and is connected to the pre-pressing roller (21).

3. The detection system according to claim 2, characterized in that: The rotation direction of the pre-pressing roller (21) is opposite to that of the back roller body (22); the rotation directions of the pre-pressing roller (21) arranged opposite to each other are opposite.

4. The detection system according to claim 2, characterized in that: The back roller body (22) includes an upper back roller (31) and a lower back roller (32), and the pre-pressing roller (21) includes an upper pressure roller (33) and a lower pressure roller (34); the upper back roller (31) and the upper pressure roller (33) are synchronously raised and lowered, and / or the lower back roller (32) and the lower pressure roller (34) are synchronously raised and lowered.

5. The detection system according to claim 1, characterized in that: The pre-pressing roller device (2) further includes a cleaner (23), which is disposed opposite to the surface of the pre-pressing roller (21) and is used to remove impurities from the surface of the pre-pressing roller (21).

6. The detection system according to claim 1, characterized in that: A sensor (42) is provided in front of the pre-pressing roller device (2), and the sensor (42) is used to detect the thickness of the battery electrode (1).

7. The detection system according to claim 6, characterized in that: When the sensor (42) detects that the thickness of the battery electrode (1) is greater than the second preset value, the pre-pressure roller (21) separates from the battery electrode (1) to avoid the bonding area on the battery electrode (1); when the sensor (42) detects that the thickness of the battery electrode (1) is less than or equal to the second preset value, the pre-pressure roller (21) abuts against the battery electrode (1).

8. The detection system according to claim 1, characterized in that: The detection system also includes a feed roller (51) and a discharge roller (52), which are located in front of and behind the pre-compression roller device (2), respectively. The feed roller (51) and the discharge roller (52) are supported on the lower surface of the battery electrode (1). The straight line direction of the axis of the feed roller (51) and the axis of the discharge roller (52) is perpendicular to the straight line direction of the axis of the pre-compression roller (21) which is arranged opposite to it.

9. A testing method, comprising testing a battery electrode (1) after coating and drying using the testing system described in any one of claims 1-8, characterized in that: The detection method includes controlling the pre-pressing roller (21) to pre-press the battery electrode (1) to change the surface roughness of the battery electrode (1); An image of the surface of the battery electrode (1) is obtained, and the roughness of the surface of the battery electrode (1) in the image is identified. The area with roughness greater than a first preset value is a defect area, and the area with roughness less than or equal to the first preset value is a normal area.

10. The detection method according to claim 9, characterized in that: The control pre-compression roller (21) performs pre-compression treatment on the battery electrode (1) including... Obtain the thickness parameter of the battery electrode (1). If the thickness parameter is less than or equal to the second preset value, control the pre-pressing roller (21) to pre-press the battery electrode (1). If the thickness parameter is greater than the second preset value, control the pre-pressing roller (21) to separate from the battery electrode (1).

Images