Pole piece slicing system and control method thereof

Abstract

This invention provides an electrode slicing system and its control method. The electrode slicing system of this invention includes a first traction roller, a second traction roller, a third traction roller, a fourth traction roller, and an output device arranged sequentially along the electrode conveying direction, as well as two slicing sections disposed on both sides of the second traction roller; each traction roller has the same structure. The electrode slicing system of this invention, by setting up the first, second, third, and fourth traction rollers and placing the two slicing sections on both sides of the second traction roller, has a simple structure and convenient arrangement. It can cut two electrode sheets at a time, which helps improve production efficiency. Furthermore, by controlling the speed of the four traction rollers, the electrode sheets conveyed to the output device can reach a preset spacing, facilitating subsequent operations.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to an electrode slicing system. Furthermore, this invention also relates to a control method for the electrode slicing system. Background Technology

[0002] Lithium-ion batteries are high-capacity, long-life, and environmentally friendly batteries with numerous advantages, widely used in energy storage, electric vehicles, and portable electronic products. Electrodes are the foundation of lithium-ion power batteries, directly determining their electrochemical performance and safety. A lithium battery cell is composed of multiple electrodes and separators stacked in an alternating pattern. Before forming, the electrodes are in a strip-like structure, cut into individual pre-defined electrode sheets by a slicing system. However, limited by the structure and control methods of existing electrode slicing systems, it is difficult to solve the problem of electrode spacing, resulting in low production efficiency while ensuring that the cut electrodes reach the pre-defined spacing during transport. Summary of the Invention

[0003] In view of this, the present invention aims to provide an electrode slicing system that facilitates the achievement of a preset spacing between each cut electrode during the conveying process and improves production efficiency.

[0004] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0005] An polarimeter slicing system, comprising:

[0006] The first traction roller, the second traction roller, the third traction roller, the fourth traction roller and the output device are arranged sequentially along the electrode conveying direction, and two slicing sections are provided on both sides of the second traction roller;

[0007] All traction rollers have the same structure.

[0008] Furthermore, it also includes an adjustment section for adjusting the spacing between two adjacent traction rollers; and / or,

[0009] The sliced ​​section is a laser.

[0010] Furthermore, the distance between the first traction roller and the second traction roller is greater than the distance between the second traction roller and the third traction roller;

[0011] The distance between the second traction roller and the third traction roller is the same as the distance between the third traction roller and the fourth traction roller.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] The electrode slicing system of the present invention has a simple structure and convenient arrangement. It can cut two electrode sheets at a time, which can improve production efficiency. Furthermore, by controlling the speed of the four traction rollers, the electrode sheets conveyed to the output device can reach a preset spacing, which facilitates subsequent operations.

[0014] Another objective of this invention is to provide a control method for an electrode slicing system. The control method includes controlling the conveying device to convey the electrode at a preset speed v0 at a uniform speed, and controlling each traction roller to run in the order of acceleration stage, first uniform speed stage, first deceleration stage, second uniform speed stage and second deceleration stage.

[0015] During the acceleration phase, both the first traction roller and the second traction roller move at a first preset acceleration a. m The third and fourth traction rollers accelerate at a second preset acceleration, where the second preset acceleration a0 is greater than the first preset acceleration a0. m ;

[0016] During the first uniform speed phase, each traction roller rotates at a first preset speed v. m It runs and simultaneously enters the first deceleration phase;

[0017] During the second uniform speed stage, the linear velocity of each traction roller is the same as the conveying speed v0 of the electrode sheet, and the first traction roller, the second traction roller, and the third traction roller enter the second deceleration stage before the fourth traction roller.

[0018] Furthermore, the first traction roller, the second traction roller, and the third traction roller are controlled to operate at the first preset acceleration a during the second deceleration phase. m During deceleration, the fourth traction roller is controlled to operate at a second preset acceleration a during the second deceleration phase. n Slow down the speed.

[0019] Furthermore, the running time t0 of the third traction roller and the fourth traction roller during the acceleration phase satisfies: t0 = v m / a m ;

[0020] The running time t1 of the first traction roller and the second traction roller during the acceleration phase satisfies: t1 = v m / a0,v m (t1-t0) / 2=L0;

[0021] The relationship between the running time t2 of the third traction roller and the fourth traction roller in the first uniform speed stage and the running time t3 in the first deceleration stage satisfies:

[0022] v m t0 / 2+v m t2+(v0+v m )t3 / 2=v0(t0+t2+t3)+L1-L0;

[0023] (v m -v0) / t3=a m Where L0 is the preset target distance between the two electrodes, and L1 is the initial distance between the cut electrode and the uncut strip.

[0024] Furthermore, the relationship between the running time t4 of the first traction roller, the second traction roller, and the third traction roller in the second uniform speed stage and the running time t5 of the first traction roller, the second traction roller, and the third traction roller in the second deceleration stage satisfies:

[0025] v0t4+v0t5 / 2+v m t1 / 2+v m (t2-t1+t0)+(v0+v m )t3 / 2=2L2;

[0026] v0 / t5=a m ;

[0027] Where L2 is the preset length of the electrode.

[0028] Furthermore, the relationship between the running time t6 of the fourth traction roller in the second uniform speed stage and the running time t7 of the fourth traction roller in the second deceleration stage satisfies:

[0029] v0(t6-t5-t4)=L1-L3-v0t5 / 2;

[0030] t7 = v0 / a n ;

[0031] L3 = v0t7;

[0032] Wherein, L3 is the vertical distance between the cut electrode sheet and the axis of the fourth traction roller.

[0033] The control method of the electrode slicing system described in this invention controls each traction roller to operate in the sequence of acceleration stage, first uniform speed stage, first deceleration stage, second uniform speed stage, and second deceleration stage. By differentiating the acceleration of the first and second traction rollers from that of the third and fourth traction rollers in the first acceleration stage, it is beneficial to achieve the electrode tracking distance. Furthermore, the electrode cutting time can be controlled within the time period from when the first, second, and third traction rollers decelerate to 0 until the fourth traction roller decelerates to 0, ensuring the compactness of the electrode cutting and conveying process and improving the production efficiency of the electrode. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0035] Figure 1 This is a schematic diagram of the structure of the electrode slicing system described in an embodiment of the present invention;

[0036] Figure 2 This is a graph showing the speed and time of each traction roller within one motion cycle according to an embodiment of the present invention.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. First traction roller; 2. Second traction roller; 3. Third traction roller; 4. Fourth traction roller; 5. First slicing section; 6. Second slicing section; 7. Uncut strip; 8. Cut electrode sheet; 9. Conveyor belt; 10. Drive roller. Detailed Implementation

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0040] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0041] Furthermore, in the description of this invention, unless otherwise explicitly defined, the terms "installation," "connection," "linking," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention in light of the specific circumstances.

[0042] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0043] Example 1

[0044] This embodiment relates to an electrode slicing system, the overall structure of which is as follows: Figure 1 As shown, the electrode slicing system includes a first traction roller 1, a second traction roller 2, a third traction roller 3, a fourth traction roller 4 and an output device arranged sequentially along the electrode conveying direction, as well as two slicing sections located on both sides of the second traction roller 2. Each traction roller has the same structure.

[0045] The electrode slicing system of this embodiment is equipped with a first traction roller 1, a second traction roller 2, a third traction roller 3, and a fourth traction roller 4, with two slicing sections located on both sides of the second traction roller 2. The structure is simple and easy to arrange, and it can cut two electrode sheets at a time, which helps to improve production efficiency. Furthermore, by controlling the speed of the four traction rollers, the electrode sheets conveyed to the output device can reach a preset spacing, which facilitates subsequent operations.

[0046] Based on the above overview, as a preferred embodiment, the electrode slicing system of this embodiment further includes an adjustment unit for adjusting the spacing between two adjacent traction rollers, and the slicing unit is a laser. In specific implementations, the adjustment unit may include a linear motor commonly used in the prior art, and the linear motor may be configured corresponding to each traction roller. Each traction roller is respectively mounted on its corresponding linear motor, thereby adjusting the position of each traction roller in the horizontal direction, and thus adjusting the spacing between two adjacent traction rollers.

[0047] By incorporating an adjustment mechanism to adjust the distance between adjacent rollers, the production of electrodes of different lengths can be carried out by adjusting the distance between the two rollers accordingly, thus meeting the production requirements of electrodes of different lengths. Furthermore, the cutting section is a laser, which helps to improve cutting efficiency while reducing electrode wear during the cutting process.

[0048] Of course, in this embodiment, the adjustment part is provided to adjust the distance between the two rollers, which is only a preferred implementation. In other embodiments, the adjustment part may not be provided. In addition, in other embodiments, other commonly used electrode cutting devices in the prior art, such as metal punching dies, may be used to cut the electrode sheets.

[0049] In a preferred embodiment, the distance between the first traction roller 1 and the second traction roller 2 is greater than the distance between the second traction roller 2 and the third traction roller 3. The distance between the second traction roller 2 and the third traction roller 3 is the same as the distance between the third traction roller 3 and the fourth traction roller 4.

[0050] It should be noted that, as Figure 1 As shown in the illustration, the electrode tracking distance mentioned in this embodiment specifically refers to the following: During the laser cutting process, the first traction roller 1, the second traction roller 2, and the third traction roller 3 need to be stopped. At this time, since the electrode in front and the cut electrode continue to be conveyed forward, the uncut strip 7 will pull apart from the cut electrode. To facilitate subsequent production, the electrode being cut needs to catch up with the electrode in front after being cut, maintaining a preset distance. Furthermore, since this embodiment has two cutting sections, that is, two electrode sheets can be cut at a time. Immediately after cutting, there is no gap between the two electrode sheets. It is necessary to ensure that a preset gap is also formed after they are conveyed to the output device.

[0051] In this embodiment, the electrode slicing system has four traction rollers and two slicing sections located on both sides of the second traction roller 2. The structure is simple and easy to arrange. At the same time, it can cut two electrode sheets at a time, which helps to improve production efficiency. Furthermore, by controlling the speed of the four traction rollers, the electrode sheets conveyed to the output device can reach a preset spacing, which facilitates subsequent operations.

[0052] Example 2

[0053] This embodiment relates to a control method for an electrode slicing system, used to control the electrode slicing system of Embodiment 1. The control method for the electrode slicing system includes controlling the conveying device to convey the electrode at a preset speed v0 at a uniform speed, and controlling each traction roller to run in the order of acceleration stage, first uniform speed stage, first deceleration stage, second uniform speed stage and second deceleration stage.

[0054] During the acceleration phase, both the first traction roller 1 and the second traction roller 2 move at a first preset acceleration a. m Acceleration is achieved by both the third traction roller 3 and the fourth traction roller 4 accelerating at a second preset acceleration, where the second preset acceleration a0 is greater than the first preset acceleration a. m During the first uniform speed phase, each traction roller rotates at a first preset speed v.m The system operates and simultaneously enters the first deceleration stage. In the second uniform speed stage, the linear velocity of each traction roller is the same as the conveying speed v0 of the electrode sheet, and the first traction roller 1, the second traction roller 2, and the third traction roller 3 enter the second deceleration stage before the fourth traction roller 4.

[0055] By controlling each traction roller to operate in an acceleration phase, a first uniform speed phase, a first deceleration phase, a second uniform speed phase, and a second deceleration phase, it is beneficial for the electrode sheets that are cut later to catch up with the ones that are cut earlier. Furthermore, the acceleration of the third traction roller 3 and the fourth traction roller 4 in the acceleration phase is greater than the acceleration of the first traction roller 1 and the second traction roller 2, facilitating the simultaneous cutting of two electrode sheets and increasing the spacing between them. Additionally, by ensuring that the conveying device transports the electrode sheets at a preset uniform speed, the production efficiency of the electrode sheets is improved.

[0056] Furthermore, by having the first traction roller 1, the second traction roller 2, and the third traction roller 3 enter the second deceleration stage before the fourth traction roller 4, the fourth traction roller 4 can still convey the pre-cut electrode sheets forward after the first traction roller 1, the second traction roller 2, and the third traction roller 3 have decelerated to 0. Moreover, the cutting time of the electrode sheets can be controlled within the time period from when the first traction roller 1, the second traction roller 2, and the third traction roller 3 have decelerated to 0 until the fourth traction roller 4 has decelerated to 0, thus ensuring the compactness of the electrode sheet cutting and conveying process and improving the production efficiency of the electrode sheets.

[0057] Furthermore, the conveying device in this embodiment can be a belt commonly used in the prior art for conveying electrode sheets. For ease of understanding of this embodiment, the following description will use the following example to illustrate the relationships satisfied by the time periods of operation in subsequent stages: manufacturing an electrode sheet with a length of 209.5 mm; the distance between the second traction roller 2 and the third traction roller 3 being 170 mm; the distance between the third traction roller 3 and the fourth traction roller 4 being 170 mm; the distance between the fourth traction roller 4 and the drive roller 10 of the conveyor belt 9 being 186 mm; the distance between the first slicing section 5 on the left and the second traction roller 2 being 174.5 mm; and the distance between the second slicing section 6 on the right and the second traction roller 2 being 35 mm.

[0058] Based on the above overview, as a preferred implementation, in this embodiment, it is preferable to control the first traction roller 1, the second traction roller 2, and the third traction roller 3 to all accelerate at a first preset acceleration a during the second deceleration phase. m During deceleration, the fourth traction roller 4 is controlled to operate at a third preset acceleration a during the second deceleration phase. n Slow down the speed.

[0059] Furthermore, in this embodiment, the running time t0 of the third traction roller 3 and the fourth traction roller 4 during the acceleration phase satisfies: t0 = v m / a mThe running time t1 of the first traction roller 1 and the second traction roller 2 during the acceleration phase satisfies: t1 = v m / a0,v m (t1-t0) / 2=L0. The relationship between the running time t2 of the third traction roller 3 and the fourth traction roller 4 in the first uniform speed stage and the running time t3 in the first deceleration stage satisfies:

[0060] v m t0 / 2+v m t2+(v0+v m )t3 / 2=v0(t0+t2+t3)+L1-L0;

[0061] (v m -v0) / t3=a m Where L0 is the preset target distance between the two electrodes, and L1 is the initial distance between the cut electrode and the uncut strip 7.

[0062] In practical applications, the acceleration or deceleration of each traction roller is typically a maximum of 20 m / s². 2 The maximum speed of the rollers is generally limited to 1.6 m / s to ensure the safe operation of each traction roller. In this embodiment, preferably, a... m =20m / s 2 , so that a n =20.58m / s 2 And make the speeds v of the first traction roller 1, the second traction roller 2, the third traction roller 3, and the fourth traction roller 4 in the first uniform speed phase. m =1.6m / s, then the time for the third traction roller 3 and the fourth traction roller 4 in the fourth acceleration stage can be calculated as follows:

[0063] t0 = v m / a m =1.6 / 20 = 0.08s

[0064] Furthermore, in this embodiment, the conveying device can be a conveyor belt 9 commonly used in the prior art, and its uniform motion speed v0 = 0.71 m / s. Therefore, the running time t3 of the third traction roller 3 and the fourth traction roller 4 in the first uniform deceleration stage can be calculated:

[0065] t3=(v m -v0) / a m = (1.6 - 0.71) / 20 = 0.0445s

[0066] In addition, by Figure 1It can be seen that the initial distance L1 between the cut electrode 8 and the uncut strip 7 is equal to the distance L4 between the uncut strip 7 and the fourth traction roller 4 plus the distance L3 between the cut electrode and the fourth traction roller 4. Wherein, L4 = 170mm - (209.5mm + 35mm - 170mm) = 95.5mm.

[0067] Furthermore, as mentioned above, in this embodiment, the electrode cutting time is controlled within the period from when the first traction roller 1, the second traction roller 2, and the third traction roller 3 decelerate to 0 until the fourth traction roller 4 decelerates to 0. Once the fourth traction roller 4 decelerates to 0, the next operating cycle can begin immediately. To further ensure production efficiency, after the cut electrode leaves the fourth traction roller 4, the fourth traction roller 4 can be controlled to decelerate at an a... n The acceleration decelerates, and t7 = v0 / a n =0.71 / 20.58=0.0345s, L3=v0t7=0.71*0.345=24.5mm.

[0068] L1=L3+L4=24.5+94.5=120mm

[0069] a m =20m / s 2 v m Substituting the given values ​​of 1.6 m / s, t0 = 0.08 s, v0 = 0.71 m / s, t3 = 0.0445 s, L0 = 4 mm, and L1 = 120 mm into the given equations for the running time t2 of the third traction roller 3 and the fourth traction roller 4 in the first uniform speed phase and the running time t3 in the first deceleration phase, we can obtain the running time t2 = 0.1 s for the third traction roller 3 and the fourth traction roller 4 in the first uniform speed phase.

[0070] In addition, by v m From (t1-t0) / 2=L0, we can deduce t1=0.085s, and from t1=v m From / a0, we can derive a0 = 18.8235 m / s 2 Furthermore, since the first traction roller 1, the second traction roller 2, the third traction roller 3, and the fourth traction roller 4 all enter the first uniform deceleration stage together, it can be concluded that the time for the first traction roller 1 and the second traction roller to run in the first uniform speed stage is t8 = t2 + t0 - t1 = 0.095s.

[0071] Furthermore, in this embodiment, the relationship between the running time t4 of the first traction roller 1, the second traction roller 2, and the third traction roller 3 during the second uniform speed stage and the running time t5 of the first traction roller 1, the second traction roller 2, and the third traction roller 3 during the second deceleration stage satisfies:

[0072] v0t4+v0t5 / 2+v m t1 / 2+v m (t2-t1+t0)+(v0+v m )t3 / 2=2L2;

[0073] v0 / t5=a m ;

[0074] Where L2 is the preset length of the electrode.

[0075] Calculations show that t4 = 0.19015s and t5 = 0.0355s.

[0076] Furthermore, in this embodiment, the relationship between the running time t6 of the fourth traction roller 4 in the second uniform speed stage and the running time t7 of the fourth traction roller 4 in the second deceleration stage satisfies:

[0077] v0(t6-t5-t4)=L1-L3-v0t5 / 2;

[0078] t7 = v0 / a n ;

[0079] L3 = v0t7;

[0080] Wherein, L3 is the vertical distance between the axis of the cut electrode sheet 8 and the axis of the fourth traction roller 4.

[0081] Where t7 = 0.0345s, t6 = 0.3424s.

[0082] The speed and time curves of each roller in this embodiment are as follows: Figure 2 As shown in the diagram. It is worth noting that if it is necessary to cut electrode sheets of other lengths, the spacing between each roller and the spacing between each cutting section and the second traction roller 2 can be adjusted adaptively according to the length of the electrode sheet, and within the defined a... m a0, a n and v m After determining the values ​​of v0 and L0, the running time of each traction roller in each working stage can be obtained.

[0083] Furthermore, in the specific implementation process, servo motion function blocks and cam function blocks commonly used in existing technologies can be employed to establish a motion relationship between the four active rollers and the virtual main shaft through the cam function. This allows for the fitting of speed and time curves for each traction shaft, verifying the feasibility of the tracking distance effect of this control method. In this way, there is no need to verify the method using related mechanical components, which improves verification efficiency and reduces verification costs.

[0084] The control method of the electrode slicing system in this embodiment controls each traction roller to run in the sequence of acceleration stage, first uniform speed stage, first deceleration stage, second uniform speed stage and second deceleration stage. By setting different accelerations for the first traction roller 1 and the second traction roller 2, and the third traction roller 3 and the fourth traction roller 4 in the first acceleration stage, it is beneficial to achieve the electrode tracking distance. Furthermore, the electrode cutting time can be controlled within the time period from when the first traction roller 1, the second traction roller 2 and the third traction roller 3 decelerate to 0 until the fourth traction roller 4 decelerates to 0, ensuring the compactness of the electrode cutting and conveying process and improving the production efficiency of the electrode.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrode slicing system, characterized in that, include: The first traction roller, the second traction roller, the third traction roller, the fourth traction roller and the output device are arranged sequentially along the electrode conveying direction, and two slicing sections are provided on both sides of the second traction roller; All traction rollers have the same structure; The control method of the electrode slicing system includes controlling the conveying device to convey the electrode at a preset speed v0 at a uniform speed, and controlling each traction roller to run in the order of acceleration stage, first uniform speed stage, first deceleration stage, second uniform speed stage and second deceleration stage. During the acceleration phase, both the first and second traction rollers accelerate at a first preset acceleration a0, while the third and fourth traction rollers accelerate at a second preset acceleration a0. m Accelerate operation, and the second preset acceleration a m Greater than the first preset acceleration a0; During the first uniform speed phase, each traction roller rotates at a first preset speed v. m It runs and simultaneously enters the first deceleration phase; During the second uniform speed stage, the linear velocity of each traction roller is the same as the preset speed v0, and the first traction roller, the second traction roller, and the third traction roller enter the second deceleration stage before the fourth traction roller.

2. The electrode slicing system according to claim 1, characterized in that: It also includes an adjustment section for adjusting the spacing between two adjacent traction rollers; and / or, The sliced ​​section is a laser.

3. The electrode slicing system according to claim 1, characterized in that: The distance between the first traction roller and the second traction roller is greater than the distance between the second traction roller and the third traction roller; The distance between the second traction roller and the third traction roller is the same as the distance between the third traction roller and the fourth traction roller.

4. The electrode slicing system according to claim 1, characterized in that: Controlling the first traction roller, the second traction roller, and the third traction roller to operate at the second preset acceleration a during the second deceleration phase. m During deceleration, the fourth traction roller is controlled to operate at a third preset acceleration a during the second deceleration phase. n Slow down the speed.

5. The electrode slicing system according to claim 4, characterized in that: The running time t0 of the third traction roller and the fourth traction roller during the acceleration phase satisfies: t0 = v m / a m ; The running time t1 of the first traction roller and the second traction roller during the acceleration phase satisfies: t1 = v m / a0,v m (t1-t0) / 2=L0; The relationship between the running time t2 of the third traction roller and the fourth traction roller in the first uniform speed stage and the running time t3 in the first deceleration stage satisfies: v m t0 / 2+ v m t2+(v0+ v m )t3 / 2= v0(t0+t2+t3)+L1-L0; (v) m - v0) / t3 = a m Where L0 is the preset target distance between the two electrodes, and L1 is the initial distance between the cut electrode and the uncut strip.

6. The electrode slicing system according to claim 5, characterized in that: The relationship between the running time t4 of the first traction roller, the second traction roller, and the third traction roller in the second uniform speed stage and the running time t5 of the first traction roller, the second traction roller, and the third traction roller in the second deceleration stage satisfies: v0t4+ v0t5 / 2+ v m t1 / 2+ v m (t2-t1+t0)+(v0+v m )t3 / 2=2L2; v0 / t5= a m ; Where L2 is the preset length of the electrode.

7. The electrode slicing system according to claim 6, characterized in that: The relationship between the running time t6 of the fourth traction roller in the second uniform speed stage and the running time t7 of the fourth traction roller in the second deceleration stage satisfies: v0(t6-t5-t4)=L1-L3- v0t5 / 2; t7= v0 / a n ; L3=v0t7; Wherein, L3 is the vertical distance between the cut electrode sheet and the axis of the fourth traction roller.

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