A dry electrode rolling apparatus

Abstract

The application discloses a dry electrode rolling equipment, comprising: a first roller and a second roller; a thickness measuring device assembly for detecting the thickness of the same position of a first film and a second film after compounding; a marking device for marking the current collector corresponding to the target position of the electrode assembly; and a surface density detection device for identifying the mark printed by the marking device and detecting the surface density of the target position of the electrode assembly. The marking device marks the current collector corresponding to the target position of the electrode assembly, and the surface density detection device is used for detecting the surface density of the target position of the electrode assembly, so that the surface density of the electrode assembly and the thickness of the first film and the thickness of the second film are the detection data of the same position, and therefore the surface density of the single-sided film calculated in this way will not have errors due to the different detection positions of the surface density of the electrode assembly and the thickness of the film, and the accuracy of the surface density detection of the single-sided film is improved.

Description

Technical Field

[0001] This application relates to the field of battery technology, and more specifically, to a dry electrode rolling equipment. Background Technology

[0002] Dry electrode technology differs from traditional wet electrode fabrication processes. Traditional wet electrode fabrication requires large amounts of solvent to dissolve binders and active materials, forming a uniform slurry which is then coated onto the current collector. A lengthy drying process is then necessary to remove the solvent. Dry electrode technology, however, eliminates the need for large amounts of solvent, directly processing the electrode components into an electrode in a dry state, thus simplifying the manufacturing process.

[0003] The dry electrode preparation process is as follows: First, the active materials, binders and other dry electrode raw materials are fully mixed. Then, under certain pressure and temperature conditions, these raw materials are tightly bonded together and formed into a membrane with a certain strength and structure through a roller pressing device. This membrane is then directly composited onto the current collector to form an electrode assembly.

[0004] After the electrode assembly is laminated, its areal density needs to be measured using an areal density testing device. Therefore, the measured areal density represents the areal density of the diaphragms on both sides of the current collector. To determine the areal density of a single-sided diaphragm, its thickness needs to be measured, and then the areal density of that single-sided diaphragm can be obtained based on the relationship between areal density and thickness. However, the current method for calculating the areal density of a single-sided diaphragm using its thickness and the areal density of the electrode assembly contains errors.

[0005] Therefore, how to improve the accuracy of single-sided membrane surface density detection is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] In view of this, the purpose of this application is to provide a dry electrode rolling device to improve the accuracy of single-sided film surface density detection.

[0007] To achieve the above objectives, this application provides the following technical solution:

[0008] This application provides a dry electrode rolling device, comprising:

[0009] The first and second rolls are used to press the first and second films onto both sides of the current collector to form an electrode assembly.

[0010] A thickness measuring device assembly is disposed radially outside the first roll and the second roll, and is used to detect the thickness of the first diaphragm and the second diaphragm at the same position after they are laminated. After the first diaphragm and the second diaphragm are laminated on the current collector, the thickness measuring positions of the first diaphragm and the second diaphragm are symmetrical along the current collector and located between the first roll and the second roll. A plane parallel to the axis of the first roll and the second roll is used as a reference plane. The distance from the thickness measuring position of the first diaphragm to the reference plane is less than the diameter of the first roll, and the distance from the thickness measuring position of the second diaphragm to the reference plane is less than the diameter of the second roll.

[0011] The marking device is configured to mark on the current collector corresponding to the target position of the electrode assembly, wherein the target position of the electrode assembly is the thickness measurement position of the first diaphragm and the second diaphragm;

[0012] A surface density detection device is provided downstream of the marking device along the conveying direction of the electrode assembly. The surface density detection device is used to identify the marks printed by the marking device and detect the surface density of the target position of the electrode assembly.

[0013] The dry electrode rolling equipment provided in this application marks the current collector corresponding to the target position of the electrode assembly using a marking device. The target position of the electrode assembly is the thickness measurement position of the first and second films. The areal density detection device is used to detect the areal density of the electrode assembly at the target position. Since the target position of the electrode assembly is the same as the thickness measurement position of the first and second films, the areal density of the electrode assembly and the thickness of the first and second films are measured at the same position. Therefore, the areal density of the single-sided film calculated in this way will not have errors due to the different detection positions of the electrode assembly areal density and film thickness, thus improving the accuracy of the single-sided film areal density detection. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a partial structural schematic diagram of the dry electrode rolling equipment disclosed in the embodiments of this application;

[0016] Figure 2 This is a diagram showing the positional relationship between the thickness measuring device and the marking device disclosed in the embodiments of this application.

[0017] The meanings of the various reference numerals in the figure are as follows:

[0018] 110 - First roll; 120 - Second roll;

[0019] 210 - First thickness measuring device; 220 - Second thickness measuring device; 211 - First connection; 212 - Second connection; 221 - Third connection; 222 - Fourth connection;

[0020] 300 - Position sensor assembly; 301 - First position sensor; 302 - Second position sensor; 303 - Connecting arm; 304 - Connecting shaft;

[0021] 400 - Electrode assembly; 410 - First diaphragm; 420 - Second diaphragm; 430 - Current collector;

[0022] 500-Marking Device;

[0023] 600-area density detection device. Detailed Implementation

[0024] This application discloses a dry electrode rolling device to improve the accuracy of single-sided membrane surface density detection.

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] A battery cell is the smallest charging and discharging unit of a battery. A battery cell is formed by winding or stacking a positive electrode, a negative electrode, and a separator between them. The positive electrode includes a positive current collector and a positive active material. The positive current collector can be made of metals such as aluminum foil, nickel foil, or stainless steel, or a composite foil formed by combining metals and insulating materials. The positive active material includes the main positive active material, conductive agent, and binder. The main positive active material includes one or more lithium-containing positive active materials such as lithium iron phosphate, ternary materials containing nickel, cobalt, and manganese, and lithium manganese iron phosphate.

[0027] Similarly, the negative electrode sheet includes a negative current collector and a negative active material. The negative current collector can be made of metal materials such as copper foil, aluminum foil, and stainless steel, or it can be a composite foil material formed by combining metals and insulating materials. The negative active material includes the negative active material, conductive agent, binder, etc. The negative active material includes one or more of the following: artificial graphite, natural graphite, silicon carbide, silicon oxide, lithium titanate, etc.

[0028] The mainstream manufacturing processes for positive and negative electrodes currently include wet electrode fabrication and dry electrode fabrication. Dry electrode fabrication relies on dry electrode rolling equipment. This equipment gradually compacts and thins the dry electrode material between the rollers during film formation, ultimately forming the finished film. The two finished films are then laminated onto both sides of the current collector between the last set of rollers to form the electrode assembly.

[0029] After the electrode assembly is laminated, its areal density needs to be measured using an areal density testing device. Therefore, the measured areal density is the areal density of the diaphragms on both sides of the current collector. Since the areal densities of the diaphragms on both sides of the current collector may differ, in order to ensure product quality, it is necessary to ensure that the areal density of the diaphragm on both sides of the current collector meets the design requirements. This necessitates the testing of the areal density of the diaphragm on both sides of the current collector.

[0030] Research has shown that the areal density of a single-sided diaphragm can be calculated by measuring its thickness. Specifically, the thickness of the diaphragms on both rollers is measured first, followed by the areal density of the composite electrode assembly. Since the areal density of the current collector is known, subtracting the current collector's areal density from the electrode assembly's areal density gives the areal density of both diaphragms. Generally, areal density is directly proportional to thickness; therefore, dividing the areal density of both diaphragms by the sum of their thicknesses yields this proportionality coefficient. Multiplying the thickness of the corresponding diaphragm by this coefficient gives the areal density of that diaphragm side.

[0031] Then, based on the relationship between the areal density of a single-sided diaphragm and the designed areal density, operators can easily adjust the areal density of the corresponding side diaphragm by adjusting parameters such as roller speed, so that the areal density of that side diaphragm meets the design requirements.

[0032] However, in actual electrode assembly manufacturing scenarios, the areal density of the single-sided diaphragm calculated from the thickness of the single-sided diaphragm and the areal density of the electrode assembly contains errors. The applicant's research revealed that the error stems from the fact that the location for measuring the thickness of the single-sided diaphragm is different from the location for detecting the areal density of the electrode assembly, thus leading to errors in the calculated areal density.

[0033] Based on this, this application discloses a dry electrode rolling device to improve the accuracy of single-sided film surface density detection and reduce errors.

[0034] like Figure 1 As shown, the dry electrode rolling equipment disclosed in this application includes a first roll 110, a second roll 120, a thickness measuring device assembly, a marking device 500, and a surface density detection device.

[0035] It should be noted that the dry electrode rolling equipment includes not only the first roll 110 and the second roll 120, but also multiple other rolls that gradually compact and thin the dry electrode material. Since the scheme disclosed in this application only involves the two rolls at the composite position of the diaphragm and the current collector, this embodiment only describes the first roll 110 and the second roll 120 at the composite position. That is, the first diaphragm 410, the second diaphragm 420, and the current collector 430 are compacted and composited together by the first roll 110 and the second roll 120. In other words, the first roll 110 and the second roll 120 are used to press the first diaphragm 410 and the second diaphragm 420 onto both sides of the current collector 430 to form the electrode assembly 400.

[0036] The thickness measuring device assembly is disposed radially outside the first roll 110 and the second roll 120, and is used to detect the thickness of the first diaphragm 410 and the second diaphragm 420 at the same position after lamination. The mounting method of the thickness measuring device assembly on the radial outside of the first roll 110 and the second roll 120 is not limited; it can be mounted using a bracket. The thickness measuring device assembly is used to detect the thickness of the first diaphragm 410 and the second diaphragm 420 before lamination, thus obtaining the thickness of the first diaphragm and the thickness of the second diaphragm.

[0037] It should be noted that the thickness measuring device assembly detects the thickness of the first diaphragm 410 and the second diaphragm 420 at the same position on the composite electrode assembly 400. That is, the thickness measuring point of the first diaphragm 410 and the thickness measuring point of the second diaphragm 420 are located on the same straight line perpendicular to the electrode assembly 400; in other words, after the first diaphragm 410 and the second diaphragm 420 are composited onto the current collector 430, the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 are symmetrical along the current collector 430. This arrangement ensures that when the areal density measuring device detects the areal density at this position, the areal density measurement position and the thickness measurement position are the same, thus avoiding errors in the calculation of the areal density of one side of the diaphragm due to different measurement positions.

[0038] For ease of understanding, a plane located between the first roll 110 and the second roll 120, and parallel to the axes of the first roll 110 and the second roll 120 respectively, is defined as a reference plane. When the roll surfaces of the first roll 110 and the second roll 120 are in contact, the distance from the axes of the first roll 110 and the second roll 120 to the reference plane should be equal to the radii of the first roll 110 and the second roll 120.

[0039] In this embodiment, the distance from the thickness measuring position of the first diaphragm 410 to the reference plane is less than the diameter of the first roller 110, and the distance from the thickness measuring position of the second diaphragm 420 to the reference plane is less than the diameter of the second roller 120. Since the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 move as the first diaphragm 410 and the second diaphragm 420 move, the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 mentioned here refer to the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 at the moment when the thickness measuring device assembly outputs the thickness measuring signal.

[0040] The marking device 500 can be positioned at the composite position of the first roll 110 and the second roll 120, or it can be positioned downstream of the composite position (meaning downstream in the conveying direction of the electrode assembly 400, i.e., the marking device 500 needs to be positioned at the position where the first and second films have been composited on the current collector 430), for marking at the target position of the electrode assembly 400. Typically, the marking device 500 prints the mark on the current collector 430 of the electrode assembly 400.

[0041] When the marking device 500 is positioned at the combined position of the first roll 110 and the second roll 120, the current collector 430 needs to extend beyond the end faces of the first roll 110 and the second roll 120. The marking device 500 can be positioned on the end face of one of the first roll 110 and the second roll 120, and the marking can be printed on the current collector 430.

[0042] The first diaphragm 410 and the second diaphragm 420 do not cover both sides of the current collector 430. That is, the edges of the current collector 430 along its width are exposed, without covering the first diaphragm 410 and the second diaphragm 420. Marking can be printed at these locations; that is, the marking device 500 marks the current collector 430 at the target position of the electrode assembly 400. The target position of the electrode assembly 400 is the thickness measurement position of the first diaphragm 410 and the second diaphragm 420.

[0043] The marking device 500 can be an inkjet printer, meaning it can print corresponding marks on the current collector 430. It should be noted that the marking device 500 can also be other types of printing devices, as long as they can print marks on the current collector 430 that can be recognized by the identification device of the areal density detection device 600.

[0044] Along the conveying direction of the electrode assembly 400, the areal density detection device 600 is disposed downstream of the marking device 500. It is used to identify the markings printed by the marking device 500 and detect the areal density at the target position of the electrode assembly 400. That is, the areal density detection device 600 can identify the markings printed by the marking device 500, and when the markings are identified, it detects the areal density of the electrode assembly 400. The areal density here is the areal density at the target position of the electrode assembly 400, which is also the areal density at the thickness measurement position of the first diaphragm 410 and the second diaphragm 420.

[0045] The target position of the electrode assembly is the thickness measurement position of the first and second films, so that the areal density of the electrode assembly and the thickness of the first and second films are the same detection data. Therefore, the areal density of the single-sided film calculated in this way will not have errors due to the different detection positions of the areal density of the electrode assembly and the thickness of the films, thus improving the accuracy of the areal density detection of the single-sided film.

[0046] The areal density detection device 600 may include an identification device for identifying the markings printed by the marking device 500. It should be noted that the identification device can be a detection camera or other barcode scanning equipment. The markings can be corresponding identification codes, such as QR codes, barcodes, or other graphics, as long as they can be recognized by the detection camera or other identification equipment.

[0047] For ease of understanding, the projection of the thickness measurement positions of the first diaphragm 410 and the second diaphragm 420 onto the surface where the marking position of the current collector 430 is located is defined as the thickness measurement position projection. That is, the thickness measurement position projection and the mark printed by the marking device 500 are located on the same surface of the current collector 430. The line connecting the marking position and the thickness measurement position projection of the current collector 430 is parallel to the axis of the first roll 110 and the second roll 120. This embodiment is configured such that the target position of the electrode assembly 400 can be determined by the marking position.

[0048] Of course, the positional relationship between the marking position of the current collector 430 and the thickness measurement position projection should correspond to the positional relationship between the identification device of the identification mark of the surface density detection device 600 and the detection device of the surface density of the target position of the electrode assembly 400. That is, it can be ensured that when the surface density detection device 600 identifies the mark printed by the marking device 500, the surface density of the electrode assembly 400 is the surface density of the target position.

[0049] Taking the areal density detection device 600, which includes an identification device and a detection device, as an example, the identification device is used to identify the mark, and the detection device is used to detect the areal density. When the line connecting the projection of the marking position and the thickness measurement position of the current collector 430 is parallel to the axis of the first roll 110 and the second roll 120, the line connecting the identification device and the detection device is also parallel to the axis of the first roll 110 and the second roll 120.

[0050] In one specific embodiment of this application, the distance from the thickness measuring position of the first diaphragm 410 to the reference plane is less than 300 mm. Preferably, the distance from the thickness measuring position of the first diaphragm 410 to the reference plane is less than 150 mm. For example, the above distance can be 290 mm, 270 mm, 250 mm, 230 mm, 200 mm, 170 mm, 150 mm, 130 mm, 100 mm, 80 mm, 60 mm, 50 mm, 40 mm, etc.

[0051] Similarly, the distance from the thickness measuring position of the second diaphragm 420 to the reference plane is less than 300 mm. Preferably, the distance from the thickness measuring position of the second diaphragm 420 to the reference plane is less than 150 mm. For example, the above distance can be 290 mm, 270 mm, 250 mm, 230 mm, 200 mm, 170 mm, 150 mm, 130 mm, 100 mm, 80 mm, 60 mm, 50 mm, 40 mm, etc.

[0052] In a specific embodiment of this application, the thickness measuring device assembly includes a first thickness measuring device 210 and a second thickness measuring device 220. The first thickness measuring device 210 is disposed radially outside the first roll 110, and the second thickness measuring device 220 is disposed radially outside the second roll 120. The first thickness measuring device 210 and the second thickness measuring device 220 can adopt the same fixing method, or they can each choose different fixing methods according to their own installation environment. The areal density detection device 600, the first thickness measuring device 210 and the second thickness measuring device 220 can be arranged in a coplanar manner. The plane in which these three are located is perpendicular to the axis of the first roll 110 and the second roll 120, so as to ensure that the thickness measuring position of the first thickness measuring device 210 and the second thickness measuring device 220 is at the same point as the areal density measuring position of the areal density detection device 600.

[0053] Furthermore, along the axial direction of the first roll 110, the first thickness measuring device 210 is located at a distance greater than or equal to 100 mm from the edge of the first diaphragm 410. Correspondingly, along the axial direction of the second roll 120, the second thickness measuring device 220 is located at a distance greater than or equal to 100 mm from the edge of the second diaphragm 420. That is, in this embodiment, the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 are as close as possible to the middle position of the first diaphragm 410 and the second diaphragm 420 along the axial direction of the rolls, which can improve the detection accuracy.

[0054] The distance between the first thickness measuring device 210 and the axis of the first roll 110 is a first distance, and the distance between the second thickness measuring device 220 and the axis of the second roll 120 is a second distance. The first distance and the second distance can be equal. Of course, the first distance and the second distance can also be designed to be different as needed; for example, the first distance can be greater than the second distance or less than the second distance. In this embodiment, the installation method of the first thickness measuring device 210 and the second thickness measuring device 220, as well as their distance from the roll axis, are not limited.

[0055] The first thickness measuring device 210 and the second thickness measuring device 220 can both be laser thickness measuring devices. It should be noted that the first thickness measuring device 210 and the second thickness measuring device 220 can also be other types of thickness measuring devices. The embodiments of this application do not limit the type of thickness measuring device, as long as it can achieve non-contact thickness measurement.

[0056] like Figure 2 As shown in a specific embodiment of this application, for ease of understanding, the line connecting the axis of the first thickness measuring device 210 and the axis of the first roll 110 is defined as the first connecting line 211, the line connecting the axis of the marking device 500 and the axis of the first roll 110 is defined as the second connecting line 212, and the included angle between the first connecting line 211 and the second connecting line 212 is defined as the first included angle.

[0057] Similarly, the line connecting the axis of the second thickness measuring device 220 and the axis of the second roll 120 is defined as the third line 221, the line connecting the axis of the marking device 500 and the axis of the second roll 120 is defined as the fourth line 222, and the angle between the third line 221 and the fourth line 222 is defined as the second angle.

[0058] Those skilled in the art will understand that the first roll 110 and the second roll 120 rotate at the same speed but in opposite directions. Therefore, by setting the first thickness measuring device 210 and the second thickness measuring device 220 at the same angle to the combined position of the first roll 110 and the second roll 120, after the first thickness measuring device 210 and the second thickness measuring device 220 simultaneously output thickness measuring signals, the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 are located at the same position after the first diaphragm 410 and the second diaphragm 420 are combined on the current collector 430; that is, they are not offset on the two side surfaces of the current collector 430. In other words, the line connecting the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 is perpendicular to the surface of the current collector 430.

[0059] In this embodiment, the first included angle and the second included angle are equal, and the first thickness measuring device 210 and the second thickness measuring device 220 simultaneously output thickness measuring signals. That is, when the first included angle and the second included angle are equal, it means that the installation positions of the first thickness measuring device 210 and the second thickness measuring device 220 are the same relative to the circumferential surface of their respective corresponding rolls (first roll 110 and second roll 120). In this case, the first thickness measuring device 210 and the second thickness measuring device 220 simultaneously output thickness measuring signals, that is, the first thickness measuring device 210 and the second thickness measuring device 220 simultaneously detect the thickness, which can ensure that the thickness measuring position of the first diaphragm 410 and the thickness measuring position of the second diaphragm 420 are the same position of the electrode assembly.

[0060] It should be noted that the first included angle and the second included angle can also be designed to be unequal, indicating that the installation positions of the first thickness measuring device 210 and the second thickness measuring device 220 are not the same relative to the circumferential surface of their respective corresponding rolls (first roll 110 and second roll 120). In this case, the first thickness measuring device 210 and the second thickness measuring device 220 cannot output thickness measuring signals at the same time. Otherwise, it cannot be guaranteed that the thickness measuring position of the first diaphragm 410 and the thickness measuring position of the second diaphragm 420 are the same position of the electrode assembly.

[0061] When the first included angle and the second included angle are not equal, the time difference between the output thickness measurement signals of the first thickness measuring device 210 and the second thickness measuring device 220 is proportional to the angle difference between the first included angle and the second included angle. That is, the thickness measuring device corresponding to the larger of the first included angle and the second included angle outputs the thickness measurement signal later, and the greater the angle difference between the first included angle and the second included angle, the greater the time difference between the output thickness measurement signals of the first thickness measuring device 210 and the second thickness measuring device 220.

[0062] It should be noted that the time difference between the thickness measurement signals output by the first thickness measuring device 210 and the second thickness measuring device 220 is also related to the rotational speed of the first roll 110 and the second roll 120. The faster the rotational speed of the rolls, the shorter the time difference between the output thickness measurement signals, and vice versa. Specifically, those skilled in the art can calculate the time required for the rolls to rotate by the angle difference between the first and second included angles based on the angle difference and the rotational speed of the rolls, and use this time as the time difference between the output thickness measurement signals of the first thickness measuring device 210 and the second thickness measuring device 220.

[0063] like Figure 1 As shown in a specific embodiment of this application, the dry electrode rolling equipment may further include a position sensor assembly 300. That is, in this embodiment, the position sensor assembly 300 is used to ensure the consistency between the thickness measurement position and the surface density measurement position.

[0064] The position sensor assembly 300 includes a first position sensor 301 and a second position sensor 302. It should be noted that the first position sensor 301 and the second position sensor 302 are not limited to one, and the actual number of the first position sensor 301 and the second position sensor 302 can be selected according to the requirements.

[0065] One of the first position sensor 301 and the second position sensor 302 is a transmitting unit, and the other is a receiving unit that receives signals sent by the transmitting unit. That is, the two are used together. The transmitting unit is used to send signals. When the transmitting unit and the receiving unit are facing each other, the receiving unit can receive the signals sent by the transmitting unit, thereby determining the corresponding position.

[0066] The first position sensor 301 is eccentrically connected to the target roll, meaning that the first position sensor 301 cannot be coaxially installed on the axis of the target roll. It needs to be at a certain distance from the axis of the target roll. The specific distance value can be designed according to the requirements. This embodiment does not limit the above distance value.

[0067] The marking device 500 and the target thickness measuring device are equipped with a second position sensor 302. The target roll is at least one of the first roll 110 and the second roll 120. That is, the first position sensor 301 can be installed on only one of the first roll 110 and the second roll 120, or on both the first roll 110 and the second roll 120. The target thickness measuring device is one of the first thickness measuring device 210 and the second thickness measuring device 220 corresponding to the target roll.

[0068] When the second position sensor 302 on the target thickness measuring device is connected to the first position sensor 301, the target thickness measuring device outputs a detection signal. It should be noted that the target thickness measuring device may be positioned differently on the first roll 110 and the second roll 120, therefore the time at which it senses the first position sensor 301 may also differ. The key is to ensure that the thickness measuring positions on the first diaphragm 410 and the second diaphragm 420 are at the same position when they are combined. Therefore, when both the first roll 110 and the second roll 120 are equipped with the first position sensor 301, if the installation positions of the first thickness measuring device 210 and the second thickness measuring device 220 are different (i.e., the first included angle and the second included angle are not equal), the first thickness measuring device 210 and the second thickness measuring device 220 cannot output thickness measuring signals simultaneously. The farther the path from the combined position, the earlier the thickness measuring signal is output; the closer the path, the later the thickness measuring signal is output, ensuring that the thickness measuring positions of the first diaphragm 410 and the second diaphragm 420 coincide when they are combined.

[0069] If the first thickness measuring device 210 and the second thickness measuring device 220 are installed in the same position, that is, the first included angle and the second included angle are equal, the first thickness measuring device 210 and the second thickness measuring device 220 will output thickness measuring signals simultaneously.

[0070] The first thickness measuring device 210 and the second thickness measuring device 220 simultaneously output detection signals. That is, in this embodiment, the time when the second position sensor 302 on the target thickness measuring device senses the first position sensor 301 is taken as the thickness measuring time of the first thickness measuring device 210 and the second thickness measuring device 220.

[0071] When the second position sensor 302 on the marking device 500 is connected to the first position sensor 301, the marking device 500 marks the electrode assembly 400. That is, in this embodiment, the time when the second position sensor 302 and the first position sensor 301 on the marking device 500 sense each other is taken as the marking time of the marking device 500 on the electrode assembly 400.

[0072] Since the first position sensor 301 rotates synchronously with the target roll, and the diaphragm on the target roll moves synchronously with the target roll, when the second position sensor 302 on the target thickness measuring device and the second position sensor 302 on the marking device 500 sense the same first position sensor 301, the target thickness measuring device and the marking device 500 will correspond to the same position of the diaphragm. Therefore, the thickness measuring position corresponds to the marking position. Since the marking position is the same as the surface density measuring position, the consistency between the thickness measuring position and the surface density measuring position can be guaranteed.

[0073] In one specific embodiment of this application, the first position sensor 301 is directly or indirectly connected to the end face of the target roll. This application does not limit the installation method of the first position sensor 301 on the end face of the target roll.

[0074] Taking the indirect connection of the first position sensor 301 to the end face of the target roll via a connecting assembly as an example, the connecting assembly may include a connecting shaft 304 and a connecting arm 303. The connecting shaft 304 is coaxially connected to the end face of the target roll, and the connecting arm 303 is connected to the connecting shaft 304. The first position sensor 301 is connected to the connecting arm 303. The connecting arm 303 may extend radially. The longer the connecting arm 303, the greater the installation eccentricity of the first position sensor 301 (i.e., the distance between the first position sensor 301 and the axis of the target roll); conversely, the shorter the connecting arm 303, the smaller the installation eccentricity of the first position sensor 301. Those skilled in the art can select the length of the connecting arm 303 based on design requirements.

[0075] In one specific embodiment of this application, multiple first position sensors 301 can be provided and arranged at intervals around the axis of the target roll. With this arrangement, when the target roll rotates once, the second position sensor 302 on the target thickness measuring device can complete the sensing connection process with each of the first position sensors 301. Then, the first thickness measuring device 210 and the second thickness measuring device 220 will measure the thickness multiple times, and the number of thickness measurements is the same as the number of first position sensors 301.

[0076] Each thickness measurement location needs to correspond one-to-one with the marking location. That is, when the areal density detection device 600 determines the location for detecting areal density by scanning the code, it can establish a correlation with each thickness measurement location. It should be noted that, alternatively, the location of each thickness measurement can be not correlated with the location of the areal density measurement. Instead, the average of the thickness values ​​measured each time can be used as the target thickness value, and the areal density value measured each time can be used as the target areal density value. The target thickness value and the target areal density value can then be used as parameters to calculate the areal density of the single-sided membrane.

[0077] Furthermore, the first position sensors 301 are evenly arranged around the axis of the target roll. It should be noted that the first position sensors 301 may also be unevenly arranged, and those skilled in the art can arbitrarily set the position of each first position sensor 301 based on design requirements.

[0078] In one specific embodiment of this application, the first position sensor 301 is a transmitting unit, and the second position sensor 302 is a receiving unit. Of course, the first position sensor 301 can also be a receiving unit, and the second position sensor 302 can be a transmitting unit.

[0079] In a specific embodiment of this application, for ease of understanding, the line connecting the axis of the target thickness measuring device and the axis of the target roll is defined as the first target line, the line connecting the axis of the marking device 500 and the axis of the target roll is defined as the second target line, and the angle between the first target line and the second target line is the target angle.

[0080] The angle between any two adjacent first position sensors 301 and the axis of the target roll is not less than the target angle. This setting easily ensures that the thickness measurement position corresponds one-to-one with the marking position each time. Since the target angle is less than or equal to the angle between any two adjacent first position sensors 301 and the axis of the target roll, when the second position sensor 302 on the target thickness measurement device senses the first position sensor 301, the first position sensor 301 sensed by the second position sensor 302 on the target thickness measurement device will be the same as the first position sensor 301 sensed by the second position sensor 302 on the target thickness measurement device previously. This facilitates the correspondence between the thickness measurement position and the marking position.

[0081] In a specific embodiment of this application, the correspondence between the thickness measurement position and the marking position can be achieved even without the position sensor assembly 300. The first included angle is a°, and the second included angle is b°. After the first thickness measuring device 210 measures the thickness, the outer circumferential surface of the first roller 110 rotates by a first preset arc length, and the marking device 500 marks the electrode assembly 400; or, after the second thickness measuring device 220 measures the thickness, the outer circumferential surface of the second roller 120 rotates by a second preset arc length, and the marking device 500 marks the electrode assembly 400. That is, in this embodiment, only the thickness measurement by either the first thickness measuring device 210 or the second thickness measuring device 220 needs to be used as the starting point for calculation to determine the marking timing.

[0082] S1 = (a° / 180°) × π × r, S2 = (b° / 180°) × π × r, where S1 is the first preset arc length in mm, S2 is the second preset arc length in mm, and r is the radius of the first roll 110 and the second roll 120 in mm.

[0083] Taking the following example, after the first thickness measuring device 210 measures the thickness, the outer circumferential surface of the first roller 110 rotates by a first preset arc length, and the marking device 500 marks the electrode assembly 400. Since the thickness measuring position on the outer circumferential surface of the first roller 110 is a° away from the marking position of the marking device 500, and the arc length of the central angle of the first roller 110 at a° is S1, when the first diaphragm 410 moves a distance of S1, that is, after the outer circumferential surface of the first roller 110 rotates by the first preset arc length S1, the thickness measuring position on the first diaphragm 410 moves to the marking position of the marking device 500. At this time, the marking device 500 marks the electrode assembly 400, thus ensuring the consistency between the marking position and the thickness measuring position.

[0084] a° can be 20° to 180°. For example, a° can be 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, 180°, etc.

[0085] b° can be 90°~180°. For example, a° can be 20°, 30°, 40°, 50°, 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, 180°, etc.

[0086] In a specific embodiment of this application, the dry electrode rolling equipment may further include a timer. After the first thickness measuring device 210 or the second thickness measuring device 220 measures the thickness, the timer starts timing, and after time T seconds, the marking device 500 marks the electrode assembly 400, where T = S / V; and V is the linear velocity of the first roll 110 and the second roll 120, in mm / s. When the first thickness measuring device 210 measures the thickness and the timer starts timing, S = S1; when the second thickness measuring device 220 measures the thickness and the timer starts timing, S = S2.

[0087] Taking S=S1 as an example, after the first thickness measuring device 210 measures the thickness, the timer starts timing. After time T, the first roller 110 rotates a°, and its outer circumference rotates by a first preset arc length S1. The thickness measuring position on the first diaphragm 410 moves to the marking position of the marking device 500, and the marking device 500 marks at this time.

[0088] As illustrated in this application, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not specifically refer to the singular and may also include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0089] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0090] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0091] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this application. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A dry electrode rolling mill, characterized in that, include: A first roll (110) and a second roll (120) are used to press a first diaphragm (410) and a second diaphragm (420) onto both sides of a current collector (430) to form an electrode assembly (400). A thickness measuring device assembly is disposed radially outside the first roll (110) and the second roll (120) for detecting the thickness of the first diaphragm (410) and the second diaphragm (420) before they are laminated. After the first diaphragm (410) and the second diaphragm (420) are laminated onto the current collector (430), the thickness measuring position of the first diaphragm (410) and the thickness measuring position of the second diaphragm (420) are symmetrical along the current collector (430) and located between the first roll (110) and the second roll (120). A plane parallel to the axis of the first roll (110) and the second roll (120) is used as a reference plane. The distance from the thickness measuring position of the first diaphragm (410) to the reference plane is less than the diameter of the first roll (110), and the distance from the thickness measuring position of the second diaphragm (420) to the reference plane is less than the diameter of the second roll (120). The marking device (500) is configured to mark the current collector (430) corresponding to the target position of the electrode assembly (400), the target position of the electrode assembly (400) being the thickness measurement position of the first diaphragm (410) and the second diaphragm (420); A surface density detection device (600) is disposed downstream of the marking device (500) along the conveying direction of the electrode assembly (400). The surface density detection device is used to identify the markings printed by the marking device (500) and detect the surface density of the target position of the electrode assembly (400).

2. The dry electrode rolling equipment as described in claim 1, characterized in that, The marking device (500) is located at the combined position of the first roll (110) and the second roll (120) or downstream of the combined position.

3. The dry electrode rolling equipment as described in claim 1, characterized in that, The distance from the thickness measurement position of the first diaphragm (410) to the reference plane is less than 300 mm; And / or, The distance from the thickness measurement position of the second diaphragm (420) to the reference plane is less than 300 mm.

4. The dry electrode rolling equipment as described in claim 1, characterized in that, The thickness measuring device assembly includes a first thickness measuring device (210) and a second thickness measuring device (220). The first thickness measuring device (210) is disposed on the radial outer side of the first roll (110), and the second thickness measuring device (220) is disposed on the radial outer side of the second roll (120).

5. The dry electrode rolling equipment as described in claim 4, characterized in that, Along the axial direction of the first roll (110), the first thickness measuring device (210) is at least 100 mm away from the edge of the first diaphragm (410); And / or, Along the axial direction of the second roll (120), the second thickness measuring device (220) is at least 100 mm away from the edge of the second diaphragm (420).

6. The dry electrode rolling equipment as described in claim 4, characterized in that, The line connecting the axis of the first thickness measuring device (210) and the axis of the first roll (110) is the first connecting line (211), the line connecting the axis of the marking device (500) and the axis of the first roll (110) is the second connecting line (212), and the included angle between the first connecting line (211) and the second connecting line (212) is the first included angle. The line connecting the axis of the second thickness measuring device (220) and the axis of the second roll (120) is the third line (221), the line connecting the axis of the marking device (500) and the axis of the second roll (120) is the fourth line (222), the angle between the third line (221) and the fourth line (222) is the second angle, the first angle and the second angle are equal, and the first thickness measuring device (210) and the second thickness measuring device (220) output thickness measuring signals simultaneously.

7. The dry electrode rolling equipment as described in claim 4, characterized in that, The line connecting the axis of the first thickness measuring device (210) and the axis of the first roll (110) is the first connecting line (211), the line connecting the axis of the marking device (500) and the axis of the first roll (110) is the second connecting line (212), and the included angle between the first connecting line (211) and the second connecting line (212) is the first included angle. The line connecting the axis of the second thickness measuring device (220) and the axis of the second roll (120) is the third line (221), and the line connecting the axis of the marking device (500) and the axis of the second roll (120) is the fourth line (222). The angle between the third line (221) and the fourth line (222) is the second angle. The first angle and the second angle are not equal. The time difference between the thickness measuring signals output by the first thickness measuring device (210) and the second thickness measuring device (220) is proportional to the angle difference between the first angle and the second angle.

8. The dry electrode rolling equipment as described in claim 6, characterized in that, It also includes a position sensor assembly (300), which includes a first position sensor (301) and a second position sensor (302), wherein one of the first position sensor (301) and the second position sensor (302) is a transmitting unit and the other is a receiving unit that receives signals transmitted by the transmitting unit; The first position sensor (301) is eccentrically connected to the target roll. The marking device (500) and the target thickness measuring device are provided with the second position sensor (302). The target roll is at least one of the first roll (110) and the second roll (120). The target thickness measuring device is one of the first thickness measuring device (210) and the second thickness measuring device (220) that corresponds to the target roll. When the second position sensor (302) on the target thickness measuring device is inductively connected to the first position sensor (301), the target thickness measuring device outputs a thickness measuring signal; When the second position sensor (302) on the marking device (500) is inductively connected to the first position sensor (301), the marking device (500) marks the electrode assembly (400).

9. The dry electrode rolling equipment as described in claim 8, characterized in that, The first position sensor (301) is directly or indirectly connected to the end face of the target roll.

10. The dry electrode rolling equipment as described in claim 9, characterized in that, The first position sensor (301) is indirectly connected to the end face of the target roll through a connecting component.

11. The dry electrode rolling equipment as described in claim 10, characterized in that, The connecting assembly includes a connecting shaft (304) and a connecting arm (303). The connecting shaft (304) is coaxially connected to the end face of the target roll, and the connecting arm (303) is connected to the connecting shaft (304). The first position sensor (301) is connected to the connecting arm (303).

12. The dry electrode rolling equipment as described in claim 8, characterized in that, There are multiple first position sensors (301), which are arranged at intervals around the axis of the target roll.

13. The dry electrode rolling equipment as described in claim 12, characterized in that, Each of the first position sensors (301) is evenly arranged around the axis of the target roll.

14. The dry electrode rolling equipment as described in claim 13, characterized in that, The first position sensor (301) is a transmitting unit, and the second position sensor (302) is a receiving unit.

15. The dry electrode rolling equipment as described in claim 12, characterized in that, The line connecting the target thickness measuring device and the axis of the target roll is the first target line, the line connecting the marking device (500) and the axis of the target roll is the second target line, and the angle between the first target line and the second target line is the target angle. The angle between any two adjacent first position sensors (301) and the axis of the target roll is not less than the target angle.

16. The dry electrode rolling equipment as described in claim 8, characterized in that, The target roll is one of the first roll (110) and the second roll (120). When the second position sensor (302) on the target thickness measuring device is connected to the first position sensor (301), the first thickness measuring device (210) and the second thickness measuring device (220) simultaneously output thickness measuring signals.

17. The dry electrode rolling equipment as described in claim 4, characterized in that, The distance between the axis of the first thickness measuring device (210) and the axis of the first roll (110) is the first distance, and the distance between the axis of the second thickness measuring device (220) and the axis of the second roll (120) is the second distance. The first distance and the second distance are equal.

18. The dry electrode rolling equipment as described in claim 6, characterized in that, The first included angle is a°, the second included angle is b°, after the first thickness measuring device (210) measures the thickness, the outer circumferential surface of the first roller (110) rotates by a first preset arc length, and the marking device (500) marks the electrode assembly (400); or, after the second thickness measuring device (220) measures the thickness, the outer circumferential surface of the second roller (120) rotates by a second preset arc length, and the marking device (500) marks the electrode assembly (400); S1 = (a° / 180°) × π × r, S2 = (b° / 180°) × π × r, where S1 is the first preset arc length in mm, S2 is the second preset arc length in mm, and r is the radius of the first roll (110) and the second roll (120) in mm.

19. The dry electrode rolling equipment as described in claim 18, characterized in that, a° is 20° to 180°; and / or b° is 20° to 180°.

20. The dry electrode rolling equipment as described in claim 18, characterized in that, It also includes a timer. After the thickness is measured by the first thickness measuring device (210) or the second thickness measuring device (220), the timer starts timing, and after time T seconds, the marking device (500) marks the electrode assembly (400), where T=S / V; where V is the linear velocity of the first roll (110) and the second roll (120), in mm / s. When the first thickness measuring device (210) measures the thickness and the timer starts counting, S = S1; When the second thickness measuring device (220) measures the thickness and the timer starts counting, S = S2.

21. The dry electrode rolling equipment as described in claim 4, characterized in that, Both the first thickness measuring device (210) and the second thickness measuring device (220) are laser thickness measuring devices.

22. The dry electrode rolling equipment as described in claim 1, characterized in that, The marking device (500) is an inkjet printing device.

23. The dry electrode rolling equipment according to any one of claims 1-22, characterized in that, The projection of the thickness measurement positions of the first diaphragm (410) and the second diaphragm (420) onto the surface where the marking position of the current collector (430) is located is the thickness measurement position projection. The line connecting the marking position of the current collector (430) and the thickness measurement position projection is parallel to the axis of the first roll (110) and the second roll (120).

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