Pole piece detection system and battery pole piece rolling system
By setting up an ultrasonic thickness measurement device in the battery pole roller press system to measure the upper and lower sides of the pole plate, the problem of unevenness of the coating surface density is solved, ensuring the consistency of the pole plate before rolling, and improving the product qualification rate It also reduces the risk of lithium excretion and achieves a more efficient production process.
Patent Information
- Application Number
- CN202421220060.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-30
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-05-30
AI Technical Summary
The prior art cannot effectively monitor the unevenness of the coating surface density of the battery electrode sheet, causing the female and male electrode sheet to enter the roller pressing process, causing the finished battery cell to be unqualified, and the film thickness on both sides of the electrode sheet cannot be measured separately, which increases the Lithium excision risk.
Design a pole sheet detection system, by setting a first thickness measuring device and a second thickness measuring device in front of the inlet of the rolling unit, and using an ultrasonic thickness gauge to measure the upper and lower sides of the pole sheet to ensure the consistency of surface density and tension A thickness measurement device is installed after the roller outlet to monitor the stretching of the pole sheet to prevent product problems caused by uneven surface density.
It effectively avoids the intraocular and uneven surface electrode sheets entering the roller pressure due to uneven coating surface density, improves the product pass rate, reduces the risk of lithium extraction, ensures that the electrode sheets are strictly screened before rolling, and improves production efficiency.
Smart Images
Figure CN222298759U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of battery pole piece production, and in particular to a pole piece detection system and a battery pole piece rolling system. Background Art
[0002] With the continuous development of new energy technologies, batteries are widely used in many fields such as photovoltaic energy storage, new energy vehicles, and industrial robots. In the battery production process, the coating process and the rolling process are key steps in the battery manufacturing process, especially in the production of lithium-ion batteries. The coating process is the process of coating the active material of the battery on the current collector (usually a metal foil such as copper or aluminum); the rolling process is performed after the coating process to increase the density and uniformity of the coating layer. However, the coating surface density is affected by factors such as slurry viscosity and pump speed. The surface density often fluctuates during the coating process, resulting in surface density exceeding the specification. The existing technology cannot 100% control the pole segments with poor surface density, resulting in serious positive and negative surfaces. During rolling, because the current thickness gauge can only monitor the total thickness of the pole piece, it is impossible to monitor the coating film thickness on both sides of the pole piece separately. If there is a serious positive and negative side problem in the coating, but the double-sided surface density is qualified, the electrode will directly enter the rolling process. However, the ultrasonic thickness gauge for the positive and negative side coating problem cannot measure the film thickness on both sides of the current collector separately, which will cause the positive and negative side electrodes to enter the subsequent process at the rolling point, resulting in unqualified final battery cells. Utility Model Content
[0003] In view of this, the present application provides a pole piece detection system and a battery pole piece rolling system, in order to solve the technical problem of defective battery pole piece products. In the first aspect, a pole piece detection system is provided, which is applied to a battery pole piece rolling system, and the battery pole piece rolling system includes a rolling unit for rolling the pole piece, including: a first thickness measuring device, which is installed before the entrance of the rolling unit and is arranged above the pole piece; a second thickness measuring device, which is installed before the entrance of the rolling unit and is symmetrically arranged below the pole piece with the first thickness measuring device.
[0004] In some embodiments, the pole piece includes: a pole lug region and a membrane region; the first thickness measuring device and the second thickness measuring device are symmetrically arranged on both sides of the pole lug region, or symmetrically arranged on both sides of the membrane region.
[0005] The above-mentioned electrode detection system, by setting a thickness measuring system before rolling the electrode, realizes the overall upper and lower film thickness measurement of the electrode to be rolled through the first thickness measuring device and the second thickness measuring device, and the upper and lower film thickness measurement of different areas of the electrode, so as to avoid the uneven density of the electrode due to the coating process, thereby producing electrodes with positive and negative surfaces, and excludes the electrode sheets that do not meet the process requirements before rolling, thereby improving production efficiency and product qualification rate, and avoiding product use risks caused by lithium plating of the electrode sheets.
[0006] In some embodiments, it also includes: a first track and a second track, the first thickness measuring device is installed on the first track, and the second thickness measuring device is installed on the second track; the first thickness measuring device and the second thickness measuring device move synchronously between the tab area and the membrane area along the first track and the second track respectively.
[0007] In some embodiments, it also includes: multiple thickness measurement groups, the thickness measurement groups include: a first thickness measurement device and a second thickness measurement device; the multiple thickness measurement groups include: a first thickness measurement group and a second thickness measurement group; the first thickness measurement group is arranged on both sides of the membrane area, and the second thickness measurement group is arranged on both sides of the tab area.
[0008] In some embodiments, the measurement range of the first thickness measurement group is determined based on the size of the tab region, and the measurement range of the second thickness measurement group is determined based on the size of the film region.
[0009] In some embodiments, the first thickness measuring device and the second thickness measuring device are ultrasonic thickness gauges.
[0010] In some embodiments, the battery pole sheet rolling system further includes a tension roller for stretching the pole sheet; the first thickness measuring device and the second thickness measuring device are installed after the exit of the tension roller.
[0011] In a second aspect, a battery pole piece rolling system is provided, comprising: a tension roller for stretching the pole piece; a pole piece detection system of the first aspect arranged after the outlet of the tension roller; and a rolling unit arranged after the pole piece detection system, for rolling the pole piece. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The following is a brief introduction to the drawings used in describing the embodiments of this application:
[0013] Figure 1 A schematic structural diagram of a battery pole sheet rolling system provided in an embodiment of the present application is shown;
[0014] Figure 2 A schematic diagram of the structure of a pole piece detection system provided in an embodiment of the present application is shown;
[0015] Figure 3 A schematic top view of a pole piece provided in an embodiment of the present application is shown;
[0016] Figure 4 A schematic diagram of the structure of another pole piece detection system provided in an embodiment of the present application is shown;
[0017] Figure 5 A schematic diagram of the structure of another pole piece detection system provided in an embodiment of the present application is shown.
[0018] Explanation of the accompanying drawings: 10 - pole piece, 110 - conveying mechanism, 120 - tension roller, 130 - rolling unit, 210 - first thickness measuring device, 220 - second thickness measuring device, 31 - pole ear area, 32 - membrane area, 41 - first track, 42 - second track, 51 - first thickness measuring group, 52 - second thickness measuring group. DETAILED DESCRIPTION
[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the specific implementation methods of the present application will be described below with reference to the accompanying drawings. The accompanying drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other accompanying drawings or embodiments can be obtained based on these accompanying drawings or embodiments without paying creative work. The adjustments and improvements made without departing from the concept of the present application all belong to the protection scope of the present application.
[0020] In order to simplify the drawings, each figure only schematically shows the parts related to the embodiments, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only a part of the components with the same structure or function is schematically drawn, and there may be more or less components with the same structure or function in reality.
[0021] In this application, unless otherwise clearly specified and limited, ordinal numbers, such as "first", "second", etc., are only used to distinguish and describe associated objects, and cannot be understood as indicating or implying the relative importance or order between associated objects; in addition, they do not represent the number of associated objects. "Multiple" includes two or more, and other quantifiers are similar. " / " is used to describe the relationship between associated objects, which indicates the "or" relationship between associated objects. "And / or" is used to describe the relationship between associated objects, which includes any combination relationship between associated objects, such as "a and / or b" includes: "alone a", "alone b", or "a and b". "One or more" or "at least one" in multiple objects refers to any object or any combination of multiple objects, such as "one or more of a1, a2, a3" or "at least one of a1, a2, a3" includes: "alone a1", "alone a2", "alone a3", "a1 and a2", "a1 and a3", "a2 and a3" or "a1, a2 and a3".
[0022] With the continuous development of new energy technology, batteries are widely used in many fields such as photovoltaic energy storage, new energy vehicles and industrial robots. In the battery production process, coating and rolling processes are key steps in the battery manufacturing process, especially in the production of lithium-ion batteries. The coating process is the process of coating the active material of the battery on the current collector (usually a metal foil such as copper or aluminum); the rolling process is carried out after the coating process to increase the density and uniformity of the coating layer. At present, the coating process uses X-rays or β-rays to measure the single-sided and double-sided surface density, and the rolling process uses an ultrasonic thickness gauge to measure the thickness of the pole piece; but because the coating surface density is affected by factors such as slurry viscosity, pump speed, pump pressure, die lip gap value, and coating speed, the surface density often fluctuates during the coating process, causing the surface density to exceed the specification. Considering the production cost issue, the manufacturer usually sets a few partitions. When the surface density fluctuates beyond a certain specification range, it can still pass the test. After the subsequent coating process, observe whether there are drum edges, concave and convex marks, and whether the thickness after rolling meets the standard to ensure the product qualification rate. However, this method cannot 100% control the electrode segments with poor surface density. In particular, when the single-sided surface density is lower than the standard value and the double-sided surface density is higher than the standard value, the electrode will have serious positive and negative surfaces. For example, the single-sided surface density of a certain partition of the negative electrode coating of a certain product is 131.0 (excluding substrate) ± 4.0mg / 1540.25mm 2 , 262.0 (without substrate) ± 6.0mg / 1540.25mm 2 ; When the single-sided surface density reaches the lower limit of 127mg / 1540.25mm 2 The upper limit of double-sided surface density is 268mg / 1540.25mm 2 When the surface density of the B side without substrate measured on both sides is 141mg / 1540.25mm 2 , far greater than the single-sided surface density required by the specification of 131.0 (excluding substrate) ± 4.0mg / 1540.25mm 2 , which will bring a greater risk of lithium deposition on the positive and negative surfaces. In the rolling process, because the current thickness gauge can only monitor the total thickness of the pole piece, it is impossible to monitor the coating thickness on both sides of the pole piece separately. If a serious positive and negative surface occurs in the coating process, it will not be eliminated during the detection process of the coating process because the double-sided surface density of the pole piece is qualified, and it will directly flow into the rolling process. The ultrasonic thickness gauge for the coating of the positive and negative surface problems cannot measure the thickness of the film layer on both sides of the current collector separately, which will cause the positive and negative pole pieces to not be eliminated in the rolling process, and further flow into the subsequent processes, resulting in the finished battery cell being fully charged. The surface density of the positive electrode is too high or the surface density of the negative electrode is too low, causing lithium deposition on the negative electrode side, forming lithium dendrites, which will pierce the diaphragm during the cycle and produce unqualified products.
[0023] Please refer to Figure 1 , which shows a schematic diagram of the structure of a battery pole piece rolling system provided by an embodiment of the present application. The pole piece after the coating process is sent to the battery pole piece rolling system through the conveying structure 110, and the tension of the pole piece is accurately controlled by the tension roller 120 to prevent the material from stretching or deforming. After a series of corrections and tractions, it is sent to the rolling unit 130 for rolling to increase the density and uniformity of the coating layer. In the prior art, a pole piece thickness detection mechanism is often set at the rolling unit 130 to feedback control the rolling force of the rolling unit 130. However, in this process, the pole piece thickness detection mechanism only monitors the total thickness of the pole piece. If the pole piece is thin on one side and thick on the other side, and the total thickness meets the requirements, the rolling thickness measurement will also show normal, which will cause the positive and negative pole pieces to flow out and be made into finished battery cells. The pole piece thickness detection mechanism is installed after the rolling unit. After the coated pole piece is compacted, the film surface thickness difference caused by the inconsistent surface density on both sides will be further reduced, and it is difficult to distinguish the thickness difference on both sides of the pole piece. It will bring certain lithium precipitation risks when it flows into the subsequent process.
[0024] Therefore, reference Figure 2 , which shows a schematic diagram of the structure of a pole piece detection system provided by an embodiment of the present application, which is applied to a battery pole piece rolling system. The battery pole piece rolling system includes a rolling unit 130 for rolling the pole piece, including: a first thickness measuring device 210, installed before the entrance of the rolling unit 130, and arranged above the pole piece 10; a second thickness measuring device 220, installed before the entrance of the rolling unit 130, and symmetrically arranged below the pole piece 10 with the first thickness measuring device 210.
[0025] The first thickness measuring device 210 and the second thickness measuring device 220 can measure the thickness of the upper and lower surfaces of the pole piece 10 from the coating process before entering the rolling unit 130, so as to avoid the situation where the overall surface density of the pole piece 10 meets the process requirements, but there is a large difference in thickness between the upper and lower surfaces, forming a potential yin-yang surface phenomenon. The first thickness measuring device 210 and the second thickness measuring device 220 can be ultrasonic thickness gauges, which transmit ultrasonic waves to the upper and lower surfaces of the pole piece 10 and realize the thickness calculation of the upper and lower surfaces of the pole piece through the reflection of sound waves.
[0026] refer to Figure 3, which shows a schematic top view of a pole piece provided in an embodiment of the present application, wherein the pole piece 10 includes a membrane region 31 and a tab region 32. The first thickness measuring device 210 and the second thickness measuring device 220 can be symmetrically arranged on both sides of the tab region 32, or, can be symmetrically arranged on both sides of the membrane region 31. Taking the example that the first thickness measuring device 210 and the second thickness measuring device 220 can be symmetrically arranged on both sides of the pole lug area 32, when the pole piece 10 passes through the first thickness measuring device 210 and the second thickness measuring device 220 through the conveying mechanism, the membrane area 31 can be measured first, and then the pole lug area 32 can be measured. The upper film thickness is calculated using the first thickness measuring device 210 as an example. The difference between the upper film thickness of the membrane area 31 and the upper film thickness of the pole lug area can determine the overall upper film thickness of the pole piece. Therefore, the thickness determined by the first thickness measuring device 210 at time t1 is subtracted from the thickness determined by the first thickness measuring device 210 at time t2. Time t1 is the time when the first thickness measuring device 210 generates ultrasound when detecting the membrane area 31, and time t2 is the time when the first thickness measuring device 210 generates ultrasound when detecting the pole lug area 32. Referring to the above content, the lower film thickness can be obtained by the same logic. By setting the first thickness measuring device 210 and the second thickness measuring device 220 before the rolling process, the surface density fluctuations of each partition on the same surface (i.e., the thickness of the lug area and the thickness of the membrane area) and the surface density fluctuations of different surfaces (i.e., the overall upper membrane thickness and the overall lower membrane thickness) caused by the coating surface density fluctuations can be displayed in the form of thickness, which can better intercept the pole pieces with the risk of lithium plating in the rolling process and prevent the occurrence of short circuit accidents in the finished battery cells.
[0027] In one embodiment, reference Figure 4 , which shows a schematic diagram of the structure of another electrode detection system provided in an embodiment of the present application, and also includes: a first track 41 and a second track 42, a first thickness measuring device 210 is installed on the first track 41, and a second thickness measuring device 220 is installed on the second track 42; the first thickness measuring device 210 and the second thickness measuring device 220 move synchronously between the electrode ear area and the membrane area along the first track 41 and the second track 42 respectively.
[0028] In this embodiment, the first thickness measuring device 210 and the second thickness measuring device 220 may not rely on the transmission effect of the conveying structure on the pole piece 10. The two may be moved to the membrane area 31 or the pole ear area 32 of the pole piece 10 for separate measurements through synchronous operation on the first track 41 and the second track 42, thereby improving the measurement efficiency and quickly obtaining the measurement results.
[0029] In one embodiment, reference Figure 5, which shows a schematic diagram of the structure of another electrode detection system provided in an embodiment of the present application, and also includes: multiple thickness measurement groups, the thickness measurement group includes: a first thickness measuring device 210 and a second thickness measuring device 220; the multiple thickness measurement groups include: a first thickness measurement group 51 and a second thickness measurement group 52; the first thickness measurement group 51 is arranged on both sides of the membrane area, and the second thickness measurement group 52 is arranged on both sides of the electrode ear area.
[0030] At the same time, the time difference between the first thickness measuring device 210 of the first thickness measuring group 51 and the first thickness measuring device 210 of the second thickness measuring group 52 in re-receiving information after the ultrasonic wave occurs is twice the thickness of the upper film surface. The upper film surface thickness of the electrode 10 can be calculated in real time through software programming, and the lower film surface thickness can be calculated similarly. At the same time, by setting the thickness specification of the single-side film surface, the surface density after coating can be confirmed twice before the electrode 10 enters the rolling unit for rolling. When abnormal thickness is found, it can be intercepted in time in the rolling process to improve the product qualification rate.
[0031] In one embodiment, the measurement range of the first thickness measurement group is determined based on the size of the tab area, and the measurement range of the second thickness measurement group is determined based on the size of the film area.
[0032] In one embodiment, the battery pole sheet rolling system further includes a tension roller for stretching the pole sheet; the first thickness measuring device and the second thickness measuring device are installed after the exit of the tension roller.
[0033] In a second aspect, a battery pole piece rolling system is provided, comprising: a tension roller for stretching the pole piece; a pole piece detection system of any of the above embodiments arranged after the exit of the tension roller; and a rolling unit arranged after the pole piece detection system, for rolling the pole piece.
[0034] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred implementations of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application, and these improvements and modifications should also be regarded as the protection scope of the present application.
Claims
1. A pole piece detection system, characterized in that: Applicable to a battery pole sheet rolling system, the battery pole sheet rolling system comprises a rolling unit for rolling the pole sheet, including: A first thickness measuring device is installed before the inlet of the rolling unit and is arranged above the pole piece; The second thickness measuring device is installed before the inlet of the rolling unit and is symmetrically arranged below the pole piece with the first thickness measuring device.
2. The pole piece detection system according to claim 1, characterized in that: The pole piece comprises: a pole ear area and a membrane area; The first thickness measuring device and the second thickness measuring device are symmetrically arranged on both sides of the tab area, or symmetrically arranged on both sides of the membrane area.
3. The pole piece detection system according to claim 2, characterized in that: Also includes: a first track and a second track, the first thickness measuring device being mounted on the first track, and the second thickness measuring device being mounted on the second track; The first thickness measuring device and the second thickness measuring device move synchronously between the tab area and the membrane area along the first track and the second track respectively.
4. The pole piece detection system according to claim 2 or 3, characterized in that: Also includes: A plurality of thickness measurement groups, the thickness measurement groups comprising: the first thickness measurement device and the second thickness measurement device; The plurality of thickness measurement groups include: a first thickness measurement group and a second thickness measurement group; The first thickness measurement group is arranged at two sides of the membrane area, and the second thickness measurement group is arranged at two sides of the tab area.
5. The pole piece detection system according to claim 4, characterized in that: The measurement range of the first thickness measurement group is determined based on the size of the tab area, and the measurement range of the second thickness measurement group is determined based on the size of the film area.
6. The pole piece detection system according to any one of claims 1 to 3, characterized in that: The first thickness measuring device and the second thickness measuring device are ultrasonic thickness gauges.
7. The pole piece detection system according to any one of claims 1 to 3, characterized in that: The battery pole sheet rolling system also includes a tension roller for stretching the pole sheet; The first thickness measuring device and the second thickness measuring device are installed after the tension roller exit.
8. A battery pole sheet rolling system, characterized in that: include: Tension roller, used to stretch the pole piece; A pole piece detection system according to any one of claims 1 to 7 disposed after the tension roller outlet; And a rolling unit arranged after the pole piece detection system is used to roll the pole piece.