A device for monitoring the compaction and ductility of a roll

Abstract

The utility model provides a kind of roll compaction extension monitoring device, it is related to lithium battery production technical field, comprising: roll, the front side of the roll is equipped with pole piece area density acquisition device, the rear side of the roll compaction is equipped with pole piece area density and thickness acquisition device.Affirmative effect is by setting pole piece area density acquisition device and pole piece area density and thickness acquisition device in the front and rear of roll respectively, the area density and thickness of pole piece before and after roll compaction can be realized to continuous acquisition, without shutdown sampling manual acquisition, greatly shorten the acquisition cycle and reduce test error;By combining the area density before and after roll compaction and the thickness of pole piece after roll compaction, operating personnel can master compaction condition, and then can be adjusted according to design compaction demand, avoid the hysteresis caused by manual sampling adjustment.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery production technology, and in particular to a roller compaction and extension monitoring device. Background Technology

[0002] In the complex manufacturing process of lithium batteries, the rolling process plays a crucial role in the overall performance and quality of the battery. It is not only a key step in the physical transformation of the coated electrode sheets, but also directly affects the subsequent assembly and overall performance of the lithium battery. The core task of the rolling process is to apply precise extrusion to the coated electrode sheets according to a pre-set pressure value and roll gap width. Through this extrusion, the electrode sheets can be shaped to a specific thickness, aiming to increase the coating density. Increased coating density enhances the tightness of the electrode materials, reduces internal porosity, and thus improves the electron conduction efficiency and ion diffusion rate during charging and discharging, laying the foundation for high-performance battery output. Simultaneously, ensuring that the electrode thickness meets the dimensional requirements for battery assembly is also a critical mission of the rolling process. Battery assembly is a precise process, and the dimensional matching of each component directly affects the overall structural stability and performance of the battery. If the electrode thickness does not meet the requirements, it may lead to deviations in the internal structure of the battery, such as uneven gaps between the electrodes and the separator, which in turn affects the lithium-ion transport efficiency and may even cause safety hazards such as short circuits.

[0003] However, during the rolling process, the electrode sheet is not uniformly stressed. Due to differences in material properties, the material area will stretch to a certain extent when compressed. This stretching is not a simple increase in length or width, but is accompanied by subtle changes in the internal structure, directly leading to a change in the areal density of the material area. Changes in areal density can cause significant deviations in subsequent calculations of the actual electrode compaction. These deviations may lead to incorrect judgments about the electrode compaction, thus affecting the precise control of the entire battery production process. For example, if the electrode compaction is misjudged as too high, problems such as poor contact between the electrode and the separator may occur in subsequent battery assembly stages; if the compaction is misjudged as too low, serious consequences such as insufficient battery capacity and shortened cycle life may result.

[0004] In existing technologies, compaction testing is typically performed using manual sampling. However, in practice, human error makes it difficult to accurately sample from the same location, resulting in samples that cannot truly reflect the overall state of the electrode sheets before and after rolling, leading to inaccurate test results. Furthermore, on fast-paced rolling production lines, manual sampling takes time; the process from sampling to testing and obtaining results often lags behind the production rhythm. By the time the test results are available, a batch of electrode sheets may have already completed subsequent processes. If the test results indicate problems, this batch of electrode sheets may be irreversible, resulting in wasted production resources. Moreover, the accuracy of manual sampling is also subject to significant deviations. Different operators' techniques, pressure, and sampling locations all affect the representativeness of the samples, thus impacting the reliability of the test results. This inaccuracy can lead to misjudgments of electrode compaction, affecting the overall quality and efficiency of battery production. Utility Model Content

[0005] To address the problems existing in the prior art, this utility model provides a roller compaction and extension monitoring device, including a roller, with an electrode surface density acquisition device provided on the front side of the roller and an electrode surface density and thickness acquisition device provided on the rear side of the roller.

[0006] Preferably, the electrode surface density acquisition device is a surface density meter.

[0007] Preferably, the electrode surface density and thickness acquisition device is a surface density meter with thickness acquisition function.

[0008] Preferably, the electrode surface density and thickness acquisition device includes a surface density meter and a thickness gauge disposed on the rear side of the roll.

[0009] Preferably, the thickness gauge is located on the side of the areal density meter away from the roll.

[0010] Preferably, the electrode surface density acquisition device is disposed between the unwinding device and the roll.

[0011] Preferably, the electrode surface density and thickness acquisition device is located between the roll and the winding device.

[0012] Preferably, it also includes a central control unit, which is connected to the electrode surface density acquisition device and the electrode surface density and thickness acquisition device, respectively, and is used to calculate the rolling compaction and rolling extension based on the density before rolling acquired by the electrode surface density acquisition device and the density after rolling and the thickness after rolling acquired by the electrode surface density and thickness acquisition device.

[0013] Preferably, the rolls include a first horizontal roll and a second horizontal roll arranged vertically in the same vertical plane;

[0014] The central control unit is also used to adjust the rolling pressure between the first horizontal roll and the second horizontal roll in real time when the rolling compaction is not within the preset range.

[0015] The above technical solution has the following advantages or beneficial effects:

[0016] 1) By setting electrode surface density acquisition devices and electrode surface density and thickness acquisition devices on the front and rear sides of the roll respectively, it is possible to continuously acquire the surface density and thickness of the electrode before and after rolling, without stopping the machine to manually sample, which greatly shortens the acquisition cycle and reduces test errors.

[0017] 2) By combining the areal density before and after roller pressing and the thickness of the electrode sheet after roller pressing, the operator can grasp the compaction situation and then adjust it according to the design compaction requirements, avoiding the lag caused by manual sampling and adjustment. Attached Figure Description

[0018] Figure 1 A schematic diagram of the structure of a roller compaction and elongation monitoring device is shown in a preferred embodiment of this utility model.

[0019] Figure 2 This is a schematic diagram of the electrical connection of a roller compaction and elongation monitoring device in a preferred embodiment of the present invention. Detailed Implementation

[0020] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within its scope.

[0021] In a preferred embodiment of this utility model, based on the above-mentioned problems existing in the prior art, a roller compaction and elongation monitoring device is provided, such as... Figure 1 As shown, it includes a roll 1, with an electrode surface density acquisition device 2 on the front side of the roll 1 and an electrode surface density and thickness acquisition device 3 on the rear side of the roll 1.

[0022] Specifically, in this embodiment, by installing an electrode surface density acquisition device 2 in front of the roll 1, the surface density of the electrode before entering the rolling process can be collected in real time. At the same time, by installing an electrode surface density and thickness acquisition device 3 behind the roll 1, the surface density of the electrode after rolling and the thickness of the electrode after rolling can be collected in real time.

[0023] Furthermore, compaction refers to the degree to which the coating material is compressed during the rolling process of the electrode, usually expressed as compaction density. According to the law of conservation of mass, the mass of the active material in the electrode remains unchanged before and after rolling; that is, the areal density before rolling multiplied by the area before rolling equals the areal density after rolling multiplied by the area after rolling. Simultaneously, combined with the electrode thickness after rolling, the compaction density can be calculated. By acquiring the areal density before and after rolling and the thickness after rolling in real time, the current compaction density and extension can be quickly calculated, enabling real-time monitoring of the compaction and extension status.

[0024] The formula for calculating compacted density is as follows:

[0025] Compaction = Density after roll forming / (Thickness of electrode sheet after roll forming - Thickness of foil)

[0026] The formula for calculating the extension is as follows:

[0027] Extension = Density before rolling / Density after rolling - 1.

[0028] In a preferred embodiment of this invention, the electrode surface density acquisition device 2 is a surface density meter.

[0029] Specifically, in this embodiment, since the electrode surface density acquisition device 2 is located in front of the roll 1, and before entering the rolling process, the electrode thickness is the foil thickness, and the foil thickness is usually accurately measured and recorded before production, and is a known quantity, the surface density meter here can be a surface density meter that only has the surface density acquisition function.

[0030] In a preferred embodiment of this utility model, the electrode surface density and thickness acquisition device 3 is a surface density meter with thickness acquisition function.

[0031] Specifically, in this embodiment, since it is necessary to collect the compaction density, and based on the above calculation formula for compaction density, it can be seen that when calculating compaction density, not only the density after rolling is needed, but also the thickness of the electrode sheet after rolling. Therefore, if only a surface density meter is used here, it needs to have both surface density collection function and thickness collection function.

[0032] In a preferred embodiment of the present invention, the electrode surface density and thickness acquisition device 3 includes a surface density meter 31 and a thickness gauge 32 disposed on the rear side of the roll.

[0033] Specifically, in this embodiment, in order to simultaneously obtain the surface density and the thickness of the electrode sheet after rolling, if both a surface density meter 31 and a thickness gauge 32 are provided, then the surface density meter 31 here can be a surface density meter that only has the surface density acquisition function.

[0034] In a preferred embodiment of the present invention, the thickness gauge 32 is located on the side of the surface density gauge 31 away from the roll.

[0035] In a preferred embodiment of this invention, the electrode surface density acquisition device 2 is disposed between the unwinding device 4 and the roll 1.

[0036] In a preferred embodiment of this invention, the electrode surface density and thickness acquisition device 3 is disposed between the roll 1 and the winding device 5.

[0037] In a preferred embodiment of this utility model, such as Figure 2 As shown, it also includes a central control unit 6, which is connected to the electrode surface density acquisition device 2 and the electrode surface density and thickness acquisition device 3, respectively. It is used to calculate the rolling compaction and rolling extension based on the density before rolling acquired by the electrode surface density acquisition device 2 and the density after rolling and the thickness after rolling acquired by the electrode surface density and thickness acquisition device 3.

[0038] Specifically, in this embodiment, the central control unit 6 may be equipped with a corresponding memory to store the calculation formulas for compaction and extension, thereby enabling the central control unit 6 to calculate the compaction and extension of the roll based on the collected density before and after roll pressing and the thickness after roll pressing. The calculation formulas for compaction and extension are existing technologies.

[0039] In a preferred embodiment of this utility model, there is a preset distance between the electrode surface density acquisition device 2 and the electrode surface density and thickness acquisition device 3.

[0040] The central control unit 6 sends out the first control signal and the second control signal respectively to control the electrode surface density acquisition device 2 and the electrode surface density and thickness acquisition device 3 to perform acquisition actions.

[0041] The time interval between the first control signal and the second control signal is equal to the preset distance divided by the roller speed.

[0042] Specifically, in this embodiment, to improve the accuracy of real-time data acquisition, it is necessary to ensure that the electrode surface density acquisition device 2 and the electrode surface density and thickness acquisition device 3 acquire data from the same location on the electrode. Considering that the electrode surface density acquisition device 2 and the electrode surface density and thickness acquisition device 3 are located in successive positions on the rolling production line, the central control computer 6 controls the electrode surface density acquisition device 2 to first acquire the surface density of a certain location on the electrode. Then, when the central control computer 6 moves to the location of the electrode surface density and thickness acquisition device 3, the central control computer 6 controls the electrode surface density and thickness acquisition device 3 to acquire the surface density of that location. This ensures that the two acquisition locations are the same, guaranteeing the accuracy and reliability of the data acquisition.

[0043] In a preferred embodiment of the present invention, the roller 1 includes a first horizontal roller 11 and a second horizontal roller 12 arranged vertically in the same vertical plane;

[0044] The central control unit 6 is also used to adjust the rolling pressure between the first horizontal roll 11 and the second horizontal roll 12 in real time when the rolling compaction is not within the preset range.

[0045] Specifically, in this embodiment, the surface density meter and thickness gauge form a closed-loop system before and after roller pressing, which can be adjusted in a timely manner according to the design compaction requirements, avoiding the lag caused by manual sampling and subsequent adjustment. Through online real-time data acquisition, the compaction and elongation changes during the roller pressing process can be monitored throughout the entire process. The roller pressing pressure can be adjusted according to the actual surface density of the incoming material, ensuring the designed compaction and roller pressing thickness. There is no need to stop the machine for manual sampling, reducing testing errors.

[0046] The above description is only a preferred embodiment of the present utility model and does not limit the implementation method and protection scope of the present utility model. Those skilled in the art should realize that all solutions obtained by equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present utility model.

Claims

1. A roller compaction and elongation monitoring device, characterized in that, It includes a rolling mill, with an electrode surface density acquisition device on the front side of the rolling mill and an electrode surface density and thickness acquisition device on the rear side of the rolling mill.

2. The roller compaction and elongation monitoring device according to claim 1, characterized in that, The electrode surface density acquisition device is a surface density meter.

3. The roller compaction and elongation monitoring device according to claim 1, characterized in that, The electrode surface density and thickness acquisition device is a surface density meter with thickness acquisition function.

4. The roller compaction and elongation monitoring device according to claim 1, characterized in that, The electrode surface density and thickness acquisition device includes a surface density meter and a thickness gauge located on the rear side of the roll.

5. The roller compaction and elongation monitoring device according to claim 4, characterized in that, The thickness gauge is located on the side of the areal density meter away from the roll.

6. The roller compaction and elongation monitoring device according to claim 1, characterized in that, The electrode surface density acquisition device is located between the unwinding device and the roll.

7. The roller compaction and elongation monitoring device according to claim 1, characterized in that, The electrode surface density and thickness acquisition device is located between the roll and the winding device.

8. The roller compaction and elongation monitoring device according to claim 1, characterized in that, It also includes a central control unit, which is connected to the electrode surface density acquisition device and the electrode surface density and thickness acquisition device, respectively, and is used to calculate the rolling compaction and rolling extension based on the density before rolling collected by the electrode surface density acquisition device and the density and thickness after rolling collected by the electrode surface density and thickness acquisition device.

9. The roller compaction and elongation monitoring device according to claim 8, characterized in that, The rolls include a first horizontal roll and a second horizontal roll arranged vertically in the same vertical plane; The central control unit is also used to adjust the rolling pressure between the first horizontal roll and the second horizontal roll in real time when the rolling compaction is not within the preset range.

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