A method for winding an electrode group

Abstract

This invention discloses an adjustable tab misalignment method for battery cell winding. It relates to the field of battery cell winding technology. Specifically, this application includes the following steps: Step S1: Unwinding the cathode electrode, anode electrode, and separator onto a winding needle; Step S2: Winding the cathode electrode, anode electrode, and separator onto the winding needle; Step S3: Obtaining the tab misalignment amount and comparing it with a standard misalignment amount; Step S4: Adjusting the tension of the separator unwinding; Step S5: Flipping the battery cell roll; Step S6: Unloading the battery cell roll. The adjustment of the tab misalignment in this invention is achieved by adjusting the tension of the separator unwinding through a tension adjustment mechanism. This causes the separator to exert a force on the flipped battery cell roll, resulting in relative displacement of the tabs of the multiple cathode and anode electrodes in the battery cell roll. This simplifies and improves the efficiency of adjusting the tab misalignment, increasing production efficiency, improving the accuracy of the tab misalignment adjustment, increasing the winding yield of the battery cell roll, and reducing production costs.

Description

Technical Field

[0001] This invention relates to the field of battery cell winding technology, and in particular to a battery cell winding with adjustable tab misalignment.

[0002] The bypass method. Background Technology

[0003] Currently, in the field of secondary battery production, the winding process is the mainstream process for square battery cells, characterized by high cell yield, good safety performance, and high energy density. In the winding process, the commonly used method is to first die-cut the electrode sheets, and then wind and bond the cathode electrode sheet, anode electrode sheet, and two layers of separator film on a winding needle in the order of "separator film-cathode electrode sheet-separator film-anode electrode sheet".

[0004] Because the thickness of the same coil of electrode sheets can fluctuate, this thickness variation during the winding process can cause misalignment of the electrode tabs on the wound battery cell. This affects the assembly and welding current carrying capacity of subsequent processes, so it is necessary to adjust the misalignment of the electrode tabs during the winding process. In existing technology, operators typically adjust the circumference of the winding needles frequently by peeling off Teflon tape to correct the electrode tab misalignment. This method is time-consuming and labor-intensive, and cannot guarantee the accuracy of the adjustment, thus reducing production efficiency and winding yield, and increasing production costs. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of the prior art by providing an adjustable tab misalignment method for battery cell winding, which simplifies and improves the efficiency of adjusting the tab misalignment, thereby increasing production efficiency and improving the accuracy of tab misalignment adjustment, thus improving winding yield and reducing production costs.

[0006] This invention proposes a cell winding method with adjustable tab misalignment, comprising the following steps:

[0007] Step S1: Unwind the cathode electrode, anode electrode, and diaphragm onto the winding needle;

[0008] Step S2: The coil is wound around the cathode electrode, the anode electrode, and the separator to form a cell coil, and the separator isolates the cathode electrode and the anode electrode.

[0009] Step S3: Obtain the tab misalignment of the cathode and anode plates in the battery cell roll, and compare the obtained tab misalignment with the standard misalignment.

[0010] Step S4: Based on the comparison result between the electrode misalignment amount and the standard misalignment amount, the tension adjustment mechanism adjusts the tension of the diaphragm unwinding;

[0011] Step S5: The flipping mechanism operates, driving the winding needle to flip, and the winding needle drives the battery cell winding to flip;

[0012] Step S6: The battery cell roll on the winding needle is unloaded by the unloading needle clamping mechanism.

[0013] Further, obtaining the tab misalignment of the cathode and anode plates in the battery cell roll includes:

[0014] The misalignment of the cathode and anode electrodes in the battery cell roll is measured by a CCD vision inspection unit to obtain the numerical value of the misalignment.

[0015] Further, the obtained electrode misalignment amount is compared with the standard misalignment amount, including:

[0016] Determine whether the electrode misalignment exceeds the standard misalignment. If the electrode misalignment exceeds the standard misalignment, proceed to step S4; if the electrode misalignment does not exceed the standard misalignment, skip step S4 and proceed to step S5.

[0017] Further, the standard misalignment is D1, the tab misalignment is D2, and the difference between the tab misalignment and the standard misalignment is ΔD, where ΔD = D2 - D1. Step S4 includes:

[0018] Step S4.1: Fit the data to derive the relationship between ΔD and the tension F during the unwinding of the diaphragm;

[0019] Step S4.2: Record the current value of ΔD, and calculate the tension F of the diaphragm unwinding according to the current value of ΔD using the formula.

[0020] Step S4.3: Adjust the tension F of the diaphragm unwinding to the calculated value using the tension adjustment mechanism.

[0021] Further, step S1 includes:

[0022] Step S1.1: Unwind the first layer of diaphragm to the winding needle using the first diaphragm unwinding mechanism.

[0023] Step S1.2: Unwind the cathode electrode to the winding needle using the cathode electrode unwinding mechanism;

[0024] Step S1.3: Unwind the second diaphragm to the winding needle using the second diaphragm unwinding mechanism;

[0025] Step S1.4: Unwind the anode sheet to the winding needle using the anode sheet unwinding mechanism.

[0026] Further, both the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism include a diaphragm unwinding shaft and a diaphragm guide roller. The tension adjusting mechanism is located between the diaphragm guide roller and the winding needle. Step S1.2 includes:

[0027] The diaphragm unwinding shaft outputs the diaphragm, which, after passing through the diaphragm roller and the tension adjusting mechanism in sequence, is wound onto the winding needle.

[0028] Further, the battery cell roll includes an initial battery cell roll, and step S2 includes:

[0029] The winding needle rotates around its own axis to wind together a certain length of the cathode electrode, the anode electrode, and the diaphragm to form the initial battery cell roll.

[0030] Furthermore, the battery cell roll also includes a formed battery cell roll, the flipping mechanism includes a turntable, and the winding needle is located on the turntable at a position off-axis. Step S5 includes:

[0031] Step S5.1: The turntable rotates around its own axis, driving the winding needle to flip around the axis of the turntable, and the winding needle drives the initial battery cell to flip around the axis of the turntable;

[0032] Step S5.2: The separator on the initial cell roll is cut by a cutting mechanism to form the shaped cell roll.

[0033] Furthermore, the turntable is provided with a working position and a feeding position, and the winding needle includes a first winding needle and a second winding needle. Initially, the first winding needle is located at the working position, and the second winding needle is located at the feeding position. Step S5.1 includes:

[0034] The turntable rotates around its own axis, driving the first winding needle and the second winding needle to rotate synchronously around the axis of the turntable, so that the first winding needle rotates from the working position to the unloading position, and the second winding needle rotates from the unloading position to the working position. The first winding needle drives the initial battery cell roll to rotate from the working position to the unloading position.

[0035] Furthermore, the feeding needle clamping mechanism includes an inner clamping needle and an outer clamping roller, and step S6 includes:

[0036] Step S6.1: The inner clamping pin extends into the battery cell roll and opens the battery cell roll, separating the battery cell roll from the winding pin. The winding pin is then pulled out of the battery cell roll. During the process of the inner clamping pin opening the battery cell roll, the remaining misalignment of the cathode electrode and the anode electrode in the battery cell roll is eliminated.

[0037] Step S6.2: The outer clamping roller clamps the battery cell roll on the outside, and the inner clamping needle is pulled away from the battery cell roll.

[0038] The adjustable tab misalignment battery cell winding method proposed in this invention has the following beneficial effects:

[0039] (1) In this cell winding method, the adjustment of the cell winding tab misalignment is achieved by adjusting the tension of the diaphragm unwinding through the tension adjustment mechanism, so that the diaphragm applies a certain force to the flipped cell winding, thereby causing the tabs of the cathode and anode plates in the cell winding to move in the same direction and in the same manner. This makes the adjustment of the winding cell tab misalignment simple and efficient, improves production efficiency, improves the adjustment accuracy of the tab misalignment, improves the winding yield of the cell winding, and reduces production costs.

[0040] (2) In this cell winding method, due to the influence of the thickness of the cathode electrode, anode electrode and separator, the tabs of the cathode electrode and anode electrode in the cell roll formed by winding have the same misalignment in the same direction. Therefore, the tabs of the cathode electrode and anode electrode in the cell roll are photographed by the CCD vision detection unit, and the photographed information is analyzed to obtain the accurate value of the tab misalignment in the cell roll.

[0041] (3) The battery cell winding method first fits the data to find the relationship between ΔD and the tension F of the diaphragm unwinding; then, based on the calculated value of the current ΔD, the tension F of the diaphragm unwinding can be calculated through the relationship; finally, based on the calculated tension F of the diaphragm unwinding, the tension adjustment mechanism adjusts the tension F of the diaphragm unwinding to the specified value, so that after the diaphragm adjusts the misalignment of the electrode tabs of the battery cell roll, the misalignment of the electrode tabs is within the range of the standard misalignment, thereby improving the adjustment accuracy of the electrode tab misalignment, improving the winding yield of the battery cell roll, and reducing the production cost.

[0042] (4) In this cell winding method, the cathode electrode unwinding mechanism places the cathode electrode of the required length, the anode electrode unwinding mechanism places the anode electrode of the required length, and the diaphragm length placed on the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism exceeds the required diaphragm length. Thus, in the process of making the cell roll, the cutting process of the cathode electrode and the anode electrode is eliminated, which makes the production of the cell roll simpler and more efficient and improves production efficiency.

[0043] (5) The turntable of this cell winding method is provided with a working position and a feeding position. The winding needle includes a first winding needle and a second winding needle. Initially, the first winding needle is located at the working position and the second winding needle is located at the feeding position. Therefore, by driving the first winding needle and the second winding needle to exchange positions through the turntable, the first winding needle and the second winding needle can alternately wind the cell roll, thereby making the cell roll production simpler and more efficient and improving production efficiency.

[0044] (6) When the inner clamping pin of this cell winding method applies force to the forming cell roll on the inside, it will cause the cathode and anode plates in the forming cell roll to move to a certain extent, thereby eliminating the residual misalignment of the plates in the forming cell roll, so that the forming cell roll meets the standard of qualified cell roll, further improving the winding yield of the cell roll and reducing the production cost. Attached Figure Description

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In these drawings, similar reference numerals are used to denote similar elements.

[0046] Figure 1 This is a schematic diagram of the structure of a diaphragm adjusting the amount of electrode misalignment in a battery cell winding method with adjustable electrode misalignment according to an embodiment of the present invention.

[0047] Figure 2 This is a plan view of the battery cell roll before diaphragm adjustment in a battery cell winding method with adjustable tab misalignment according to an embodiment of the present invention.

[0048] Figure 3 This is a plan view of the battery cell roll after diaphragm adjustment, according to an embodiment of the present invention, of a battery cell winding method with adjustable tab misalignment.

[0049] Figure 4 This is a plan view of the battery cell roll after the feeding clamp needle is adjusted, according to an embodiment of the present invention, of a battery cell winding method with adjustable tab misalignment.

[0050] In the diagram: 1. First winding needle; 2. Second winding needle; 3. Turntable; 4. Tension adjustment mechanism; 5. Diaphragm unwinding shaft; 6. Diaphragm roller; 7. Diaphragm; 8. Initial cell roll; 9. Formed cell roll; 10. Tab. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] An embodiment of the present invention provides a method for winding a battery cell with adjustable tab misalignment, comprising the following steps:

[0053] Step S1: Unwind the cathode electrode, anode electrode, and diaphragm 7 onto the winding needle;

[0054] Step S2: The coil is wound around the cathode electrode, the anode electrode, and the separator 7 to form a cell coil. The separator 7 isolates the cathode electrode and the anode electrode.

[0055] Step S3: Obtain the tab misalignment of the cathode and anode plates in the battery cell roll, and compare the obtained tab misalignment with the standard misalignment.

[0056] Step S4: Based on the comparison between the electrode misalignment and the standard misalignment, the tension adjustment mechanism 4 adjusts the unwinding tension of the diaphragm 7.

[0057] Step S5: The flipping mechanism operates, driving the winding needle to flip, and the winding needle drives the battery cell winding to flip;

[0058] Step S6: The battery cell roll on the winding needle is unloaded by the unloading clamping needle mechanism.

[0059] In this patent, during the winding of the battery cell, the cathode electrode, anode electrode, and two layers of separator 7 are first unwound onto the winding needle. Then, the cathode electrode, anode electrode, and two layers of separator 7 are wound in the order of "separator 7-cathode electrode-separator 7-anode electrode" to form a battery cell roll. The separator 7 isolates the cathode electrode and anode electrode, preventing short circuits caused by contact between the cathode electrode and anode electrode.

[0060] Then, the tab misalignment of the cathode and anode plates in the battery cell roll is obtained, and the obtained tab misalignment is compared with the standard misalignment. Based on the comparison result, the tension of the diaphragm 7 is adjusted by the tension adjustment mechanism 4. After the tension adjustment is completed, the flipping mechanism is run, driving the winding needle to flip, and the winding needle drives the battery cell roll to flip synchronously.

[0061] Due to the thickness of the cathode electrode, anode electrode, and separator 7, the tabs 10 of the cathode and anode electrodes in the wound cell coil exhibit the same misalignment in the same direction. During the cell coil tumbling process, the separator 7 is not cut, thus applying a force to the cell coil through the separator 7, causing the tabs 10 of the multiple layers of cathode and anode electrodes in the cell coil to produce a relative displacement in the same direction, and the direction of this displacement is opposite to the direction of the misalignment of the tabs 10 in the cell coil, thereby adjusting the misalignment of the tabs 10 in the cell coil.

[0062] Finally, the battery cell roll on the winding needle is unloaded by the unloading clamping needle mechanism, thus completing the production of the battery cell roll. In this patent, the adjustment of the misalignment of the battery cell roll tabs 10 is automatically completed during the battery cell roll production process, making the adjustment of the misalignment of the winding battery cell tabs 10 simple and efficient, thereby improving production efficiency.

[0063] Furthermore, the adjustment of the misalignment of the battery cell roll tabs 10 is achieved by precisely adjusting the tension of the diaphragm 7 during unwinding through the tension adjustment mechanism 4. This allows the diaphragm 7 to apply a specified force to the flipped battery cell roll, thereby precisely controlling the relative displacement of the tabs 10 of the multi-layer cathode and anode plates in the battery cell roll. This improves the adjustment accuracy of the tab misalignment, increases the winding yield of the battery cell roll, and reduces production costs.

[0064] Specifically, in this embodiment, obtaining the tab misalignment of the cathode and anode plates in the battery cell roll includes: measuring the tab misalignment of the cathode and anode plates in the battery cell roll using a CCD vision detection unit to obtain the value of the tab misalignment.

[0065] Due to the influence of the thickness of the cathode electrode, anode electrode, and separator 7, the tabs 10 of the cathode and anode electrodes in the wound cell roll exhibit the same misalignment in the same direction. Therefore, the tabs 10 of the cathode and anode electrodes in the cell roll are photographed by a CCD vision inspection unit, and the photographed information is analyzed to obtain the accurate value of the tab misalignment in the cell roll.

[0066] In this patent, due to the different lengths of the cathode, anode, and separator 7 in the battery cell rolls of different products, the misalignment of the tabs 10 in the wound battery cell rolls will also vary. After obtaining the precise value of the tab misalignment in the battery cell roll, the obtained tab misalignment is first compared with the standard misalignment.

[0067] If the current electrode misalignment of the battery cell roll is within the standard misalignment range, the electrode misalignment of the battery cell roll can be adjusted within a small range in the subsequent winding process to obtain a qualified battery cell roll. Therefore, it is not necessary to adjust the misalignment of the electrode 10 through the diaphragm 7. That is, in the steps of this battery cell winding method, step S4 can be skipped and step S5 can be directly performed. By operating the flipping mechanism, the winding needle is driven to flip, so that the winding needle drives the battery cell roll to flip. Finally, at the designated position, the battery cell roll on the winding needle is unloaded to complete the production of the battery cell roll.

[0068] If the current electrode misalignment of the battery cell roll exceeds the standard misalignment range, subsequent winding processes, which make minor adjustments to the electrode misalignment, will not yield a qualified battery cell roll. In this case, step S4 needs to be performed first, so that the tension adjustment mechanism 4 adjusts the unwinding tension of the diaphragm 7 according to the current electrode misalignment of the battery cell roll.

[0069] Next, in step S5, the flipping mechanism drives the winding needle to flip, causing the winding needle to rotate the battery cell roll. During the flipping process, the diaphragm 7 applies force to the battery cell roll, causing relative displacement of the tabs 10 of the multi-layer cathode and anode plates in the battery cell roll. This adjusts the tab misalignment of the battery cell roll, ensuring that the misalignment of the tabs 10 is within the standard misalignment range. Subsequent winding processes further adjust the tab misalignment within a small range, resulting in a qualified battery cell roll, thereby improving production efficiency and reducing production costs.

[0070] Specifically, in this embodiment, the standard misalignment is D1, the tab misalignment is D2, and the difference between the tab misalignment and the standard misalignment is ΔD, where ΔD = D2 - D1. Step S4 includes:

[0071] Step S4.1: Fit the data to derive the relationship between ΔD and the unwinding tension F of the diaphragm 7;

[0072] Step S4.2: Record the current value of ΔD, and calculate the tension F value of the unwinding of the diaphragm 7 based on the current value of ΔD using the formula;

[0073] Step S4.3: Adjust the tension F of the diaphragm 7 during unwinding to the calculated value using the tension adjustment mechanism 4.

[0074] As mentioned in the previous embodiment, when the tab misalignment of the battery cell roll exceeds the standard misalignment range, the tension of the diaphragm 7 is adjusted by the tension adjustment mechanism 4 to apply force to the battery cell roll during the battery cell roll flipping process, causing the tabs 10 of the multilayer cathode and anode plates in the battery cell roll to undergo relative displacement, thereby adjusting the tab misalignment of the battery cell roll so that the tab misalignment of the tabs 10 is within the standard misalignment range.

[0075] Therefore, the diaphragm 7 applies a force to the battery cell roll, adjusting the tab misalignment amount. This adjustment is made by adjusting the difference ΔD between the tab misalignment amount D2 and the standard misalignment amount D1. Since the standard misalignment amount D1 is a fixed value, after obtaining the value of the tab misalignment amount D2 through the CCD vision detection unit, the difference ΔD between the tab misalignment amount D2 and the standard misalignment amount D1 can be calculated.

[0076] In this patent, the relationship between ΔD and the unwinding tension F of the diaphragm 7 is first obtained by data fitting; then, based on the calculated current value of ΔD, the unwinding tension F of the diaphragm 7 can be calculated using the relationship; finally, based on the calculated unwinding tension F of the diaphragm 7, the tension adjustment mechanism 4 adjusts the unwinding tension F of the diaphragm 7 to a specified value. Thus, after the diaphragm 7 adjusts the tab misalignment of the battery cell roll, the tab misalignment is kept within the standard misalignment range, thereby improving the adjustment accuracy of the tab misalignment, increasing the winding yield of the battery cell roll, and reducing production costs.

[0077] In this embodiment, step S1 includes:

[0078] Step S1.1: Unwind the first layer of diaphragm to the winding needle using the first diaphragm unwinding mechanism.

[0079] Step S1.2: Unwind the cathode electrode to the winding needle using the cathode electrode unwinding mechanism;

[0080] Step S1.3: Unwind the second diaphragm to the winding needle using the second diaphragm unwinding mechanism;

[0081] Step S1.4: Unwind the anode sheet to the winding needle using the anode sheet unwinding mechanism.

[0082] Specifically, in actual implementation, when unwinding the cathode electrode, anode electrode, and diaphragm 7, the first layer of diaphragm is first unwound to the winding needle through the first diaphragm unwinding mechanism, that is, the first layer of diaphragm is located in the first layer. Then, the cathode electrode is unwound to the winding needle through the cathode electrode unwinding mechanism, that is, the cathode electrode is located in the second layer. Finally, the second layer of diaphragm is unwound to the winding needle through the second diaphragm unwinding mechanism, that is, the second layer of diaphragm is located in the third layer.

[0083] Finally, the anode electrode is unwound to the winding needle by the anode electrode unwinding mechanism, that is, the anode electrode is located in the fourth layer. This allows the cathode electrode, anode electrode, and two layers of diaphragms 7 to be unwound to the winding needle in the order of "diaphragm 7-cathode electrode-diaphragm 7-anode electrode". This allows the diaphragm 7 to isolate the cathode electrode and anode electrode, preventing the cathode electrode and anode electrode from coming into contact and causing a short circuit.

[0084] In this patent, based on the required lengths of the cathode electrode, anode electrode, and separator 7 in different product cell rolls, a cathode electrode of a corresponding length is placed on the cathode electrode unwinding mechanism, and an anode electrode of a corresponding length is placed on the anode electrode unwinding mechanism. However, the length of the separator 7 placed on the first separator unwinding mechanism and the second separator unwinding mechanism exceeds the required length of the separator 7.

[0085] Therefore, when the winding needle winds the cathode electrode, anode electrode, and diaphragm 7, it winds all the cathode electrodes on the cathode electrode unwinding mechanism and all the anode electrodes on the anode electrode unwinding mechanism into the battery cell roll. After the diaphragm 7 of a specified length on the first and second diaphragm unwinding mechanisms is wound into the battery cell roll, the diaphragm 7 remains uncut. This allows the tension adjustment mechanism 4 to adjust the tension of the unwinding of the diaphragm 7. During the flipping process of the battery cell roll, the diaphragm 7 applies a force to the battery cell roll, causing the tabs 10 of the multiple layers of cathode and anode electrodes in the battery cell roll to undergo relative displacement, thereby adjusting the amount of tab misalignment of the battery cell roll.

[0086] After the battery cell roll is flipped to the designated position, the diaphragm 7 is cut by the cutting mechanism, and finally the battery cell roll is unloaded to complete the battery cell roll production. In this way, the cutting process of the cathode and anode plates is eliminated in the battery cell roll production process, making the battery cell roll production simpler and more efficient, and improving production efficiency.

[0087] In this embodiment, both the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism include a diaphragm unwinding shaft 5 and a diaphragm guide roller 6. The tension adjusting mechanism 4 is located between the diaphragm guide roller 6 and the winding needle. Step S1.2 includes:

[0088] The diaphragm unwinding shaft 5 outputs the diaphragm 7, which is then wound onto the winding needle after passing through the diaphragm roller 6 and the tension adjustment mechanism 4 in sequence.

[0089] In this patent, both the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism include a diaphragm unwinding shaft 5 and a diaphragm guide roller 6. A diaphragm roll of a certain length is placed on the diaphragm unwinding shaft 5, and the end of the diaphragm roll is conveyed out on the diaphragm unwinding shaft 5. The tension adjustment mechanism 4 consists of two parts, one between the first diaphragm unwinding mechanism and the winding needle, and the other between the second diaphragm unwinding mechanism and the winding needle.

[0090] The end of the diaphragm roll, which originates from the diaphragm unwinding shaft 5, passes sequentially through the diaphragm guide roller 6 and the tension adjusting mechanism 4 before being wound onto the winding needle. The winding needle then winds the diaphragm 7 originating from the diaphragm unwinding shaft 5. During the winding process, the tension adjusting mechanism 4 regulates the tension of the diaphragm 7. This ensures proper tension during normal winding and, when the battery cell roll flips, applies a force to the battery cell roll, causing relative displacement of the tabs 10 of the multi-layered cathode and anode plates, thus adjusting the tab misalignment of the battery cell roll.

[0091] In this embodiment, the battery cell roll includes an initial battery cell roll 8, and step S2 includes:

[0092] The winding needle rotates around its own axis, winding together a certain length of cathode electrode, anode electrode and separator 7 to form the initial cell roll 8.

[0093] In this patent, a cathode electrode of a certain length is placed on the cathode electrode unwinding mechanism, and an anode electrode of a corresponding length is placed on the anode electrode unwinding mechanism. The length of the diaphragm 7 placed on the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism exceeds the required length of the diaphragm 7.

[0094] When the first diaphragm unwinding mechanism unwinds the first layer of diaphragm 7 onto the winding needle, the cathode electrode unwinding mechanism unwinds the cathode electrode onto the winding needle, the second diaphragm unwinding mechanism unwinds the second layer of diaphragm 7 onto the winding needle, and the anode electrode unwinding mechanism unwinds the anode electrode onto the winding needle, the winding needle rotates around its own axis to wind the cathode electrode, anode electrode, and two layers of diaphragm 7 until the cathode electrode on the cathode electrode unwinding mechanism and the anode electrode on the anode electrode unwinding mechanism are unwound. At this time, the diaphragm 7 wound onto the winding needle remains uncut, thus forming the initial cell roll 8 on the winding needle.

[0095] Furthermore, in this embodiment, the battery cell roll also includes a formed battery cell roll 9, the flipping mechanism includes a turntable 3, and the winding needle is located on the turntable 3 at a position off-axis. Step S5 includes:

[0096] Step S5.1: The turntable 3 rotates around its own axis, driving the winding needle to flip around the axis of the turntable 3, and the winding needle drives the initial battery cell roll 8 to flip around the axis of the turntable 3.

[0097] Step S5.2: The diaphragm 7 on the initial cell roll 8 is cut by the cutting mechanism to form the shaped cell roll 9.

[0098] As mentioned in the previous embodiment, the winding needle rotates around its own axis to wind the cathode electrode, the anode electrode, and the two layers of diaphragms 7 until the cathode electrode on the cathode electrode unwinding mechanism and the anode electrode on the anode electrode unwinding mechanism are unwound. The diaphragm 7 wound onto the winding needle remains uncut, and at this time, an initial cell roll 8 is formed on the winding needle.

[0099] In this patent, the flipping mechanism includes a turntable 3, with the winding needle positioned off-axis of the turntable 3. After the tension adjustment mechanism 4 adjusts the tension F of the diaphragm 7 to a specified value, the turntable 3 rotates around its own axis, driving the winding needle to flip around the axis of the turntable 3, thereby causing the initial battery cell roll 8 formed on the winding needle to flip synchronously.

[0100] During this process, since the diaphragm 7 wound onto the winding needle remains uncut, the diaphragm 7 will exert a force on the initial cell roll 8, causing the tabs 10 of the multilayer cathode and anode plates in the initial cell roll 8 to undergo relative displacement, thereby adjusting the tab misalignment of the initial cell roll 8.

[0101] When the initial cell roll 8 is flipped to the designated position and the tab misalignment is adjusted, the diaphragm 7 is cut at that position by the cutting mechanism, so that the initial cell on the winding needle is formed into a shaped cell roll 9. Finally, the shaped cell roll 9 on the winding needle is unloaded to complete the production of the cell roll.

[0102] In this embodiment, the turntable 3 is provided with a working position and a feeding position. The needle winding includes a first needle winding 1 and a second needle winding 2. Initially, the first needle winding 1 is located at the working position, and the second needle winding 2 is located at the feeding position. Step S5.1 includes:

[0103] Turntable 3 rotates around its own axis, driving the first winding needle 1 and the second winding needle 2 to rotate synchronously around the axis of turntable 3, so that the first winding needle 1 rotates from the working position to the unloading position, and the second winding needle 2 rotates from the unloading position to the working position. The first winding needle 1 drives the initial battery cell roll 8 to rotate from the working position to the unloading position.

[0104] In this patent, a working position and a feeding position are provided on the turntable 3 at a position off-axis, and the working position and the feeding position are symmetrically arranged with the axis of the turntable 3 as the center. The needle coil includes a first needle coil 1 and a second needle coil 2. Initially, the first needle coil 1 is set at the working position, and the second needle coil 2 is set at the feeding position.

[0105] When making the battery cell roll, the cathode electrode, anode electrode, and two layers of separator 7 are rolled onto the first winding needle 1. The first winding needle 1 rotates around its own axis to achieve the winding of the cathode electrode, anode electrode, and separator 7, thereby forming the initial battery cell roll 8 on the first winding needle 1.

[0106] In actual implementation, it is preferable to set the working position directly above the unloading position. When the turntable 3 rotates around its own axis, it rotates 180° counterclockwise, driving the first winding needle 1 and the second winding needle 2 to rotate 180° around the axis of the turntable 3 simultaneously, so that the first winding needle 1 rotates from the working position to the unloading position, and the second winding needle 2 rotates from the unloading position to the working position.

[0107] When the first coil needle 1 flips, it drives the initial cell coil 8 to flip synchronously around the axis of the turntable 3. During this process, the diaphragm 7 applies a force to the initial cell coil 8 on the first coil needle 1, causing the tabs 10 of the multilayer cathode and anode plates in the initial cell coil 8 to undergo relative displacement, thereby adjusting the amount of tab misalignment.

[0108] The adjustment of the electrode misalignment ends when the first coil needle 1 flips from the unloading position to the working position, causing the initial cell coil 8 to flip from the working position to the unloading position. This makes it easier for the cutting mechanism to cut the diaphragm 7 at the unloading position, so that the initial cell coil 8 on the first coil needle 1 forms a shaped cell coil 9. Finally, the unloading clamping needle mechanism unloads the shaped cell coil 9 on the first coil needle 1 at the unloading position, thus completing the production of the cell coil.

[0109] The second winding needle 2, which is flipped to the working position, can be used to make the next battery cell roll. That is, the cathode electrode, anode electrode and two layers of separator 7 for making the next battery cell roll are first unwound onto the second winding needle 2. By rotating the second winding needle 2 around its own axis, the cathode electrode, anode electrode and separator 7 are wound, thereby forming the next initial battery cell roll 8 on the second winding needle 2.

[0110] Then, the turntable 3 continues to rotate counterclockwise by 180° around its own axis, driving the first winding needle 1 and the second winding needle 2 to rotate 180° around the axis of the turntable 3 in sync, so that the second winding needle 2 rotates from the working position to the unloading position, and the first winding needle 1 rotates from the unloading position to the working position.

[0111] At this time, the second winding needle 2 drives the next initial cell winding 8 to flip from the working position to the unloading position. During this process, the diaphragm 7 applies a force to the initial cell winding 8 on the second winding needle 2, causing the tabs 10 of the multilayer cathode and anode plates in the initial cell winding 8 to undergo relative displacement, thereby adjusting the amount of tab misalignment.

[0112] When the next initial cell roll 8 reaches the unloading position, the adjustment of its tab misalignment is completed. Then, the diaphragm 7 is cut at the unloading position by the cutting mechanism, so that the initial cell roll 8 on the second winding needle 2 is formed into a shaped cell roll 9. Finally, the shaped cell roll 9 on the second winding needle 2 is unloaded at the unloading position by the unloading clamping needle mechanism, thereby completing the production of the next cell roll, making the production of cell rolls simpler and more efficient, and improving production efficiency.

[0113] In this embodiment, the feeding needle clamping mechanism includes an inner clamping needle and an outer clamping roller, and step S6 includes:

[0114] Step S6.1: The inner clamping needle extends into the battery cell roll and opens the battery cell roll to separate the battery cell roll from the winding needle. The winding needle is then pulled out of the battery cell roll. During the process of the inner clamping needle opening the battery cell roll, the remaining misalignment of the cathode and anode plates in the battery cell roll is eliminated.

[0115] Step S6.2: The outer clamping roller clamps the battery cell roll on the outside, and the inner clamping pin is pulled away from the battery cell roll.

[0116] When the winding needle drives the initial battery cell roll 8 to flip to the unloading position, the cutting mechanism cuts the diaphragm 7 at the unloading position, and the initial battery cell roll 8 on the winding needle forms a shaped battery cell roll 9. In this patent, the unloading clamping needle mechanism includes an inner clamping needle. After the initial battery cell roll 8 on the winding needle forms the shaped battery cell roll 9, the inner clamping needle extends into the shaped battery cell roll 9 and applies a force to the shaped battery cell roll 9 from the inside, thereby opening the shaped battery cell roll 9 and separating the shaped battery cell roll 9 from the winding needle, thus facilitating the removal of the winding needle from the shaped battery cell roll 9.

[0117] As mentioned in the previous embodiment: if the current electrode misalignment of the battery cell roll is within the range of the standard misalignment, the step of adjusting the unwinding tension of the diaphragm 7 by the tension adjustment mechanism 4 is skipped, and the battery cell roll on the winding needle is directly flipped to the unloading position by the flipping mechanism.

[0118] If the current electrode misalignment of the battery cell roll exceeds the standard misalignment range, the tension of the diaphragm 7 is adjusted by the tension adjustment mechanism 4 to unwind the battery cell roll on the winding needle. During the process of the flipping mechanism flipping the battery cell roll on the winding needle to the unloading position, the diaphragm 7 applies a force to the battery cell roll, causing the electrode tabs 10 of the multilayer cathode and anode plates in the battery cell roll to undergo relative displacement, thereby adjusting the electrode misalignment of the battery cell roll to the standard misalignment.

[0119] Therefore, the remaining misalignment of the tabs in the formed cell roll 9 located at the unloading position is less than or equal to the standard misalignment. When the inner clamping pin applies force to the formed cell roll 9 from the inside and opens it up, it will cause a certain degree of relative displacement of the tabs 10 of the multi-layer cathode and anode plates in the formed cell roll 9. This eliminates the remaining misalignment of the tabs in the formed cell roll 9, enabling the formed cell roll 9 to meet the standard of a qualified cell roll, further improving the winding yield of the cell roll and reducing production costs.

[0120] In this patent, the feeding clamping needle mechanism also includes an outer clamping roller. After the coiling needle is pulled out from the forming cell roll 9, the outer clamping roller clamps the forming cell roll 9 on the outside, thereby facilitating the extraction of the inner clamping needle from the forming cell roll 9, and thus realizing the feeding of the forming cell roll 9 and completing the production of the cell roll.

[0121] The above-described contents can be implemented individually or in various combinations, and these variations are all within the protection scope of this invention.

[0122] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for winding a battery cell with adjustable tab misalignment, characterized in that, Includes the following steps: Step S1: Unwind the cathode electrode, anode electrode, and diaphragm (7) onto the winding needle; Step S2: The coil is wound around the cathode electrode, the anode electrode and the separator (7) to form a cell coil, and the separator (7) isolates the cathode electrode and the anode electrode; Step S3: Obtain the tab misalignment of the cathode and anode plates in the battery cell roll, and compare the obtained tab misalignment with the standard misalignment. The obtained electrode misalignment amount is compared with the standard misalignment amount, including: determining whether the electrode misalignment amount exceeds the standard misalignment amount; if the electrode misalignment amount exceeds the standard misalignment amount, then step S4 is executed; if the electrode misalignment amount does not exceed the standard misalignment amount, then step S4 is skipped and step S5 is executed. Step S4: Based on the comparison result of the electrode misalignment amount and the standard misalignment amount, the tension adjustment mechanism (4) adjusts the unwinding tension of the diaphragm (7); The standard misalignment is D1, the tab misalignment is D2, and the difference between the tab misalignment and the standard misalignment is ΔD, where ΔD = D2 - D1. Step S4 includes: Step S4.1: Fit the data to derive the relationship between ΔD and the unwinding tension F of the diaphragm (7); Step S4.2: Record the current value of ΔD, and calculate the tension F of the unwinding of the diaphragm (7) based on the current value of ΔD using the formula; Step S4.3: Adjust the unwinding tension F of the diaphragm (7) to the calculated value using the tension adjustment mechanism (4); Step S5: The flipping mechanism operates, driving the winding needle to flip, and the winding needle drives the battery cell winding to flip; If the tab misalignment exceeds the standard misalignment, during the cell roll flipping process, the diaphragm (7) applies force to the cell roll, causing the tabs (10) of the multiple cathode and anode plates in the cell roll to undergo relative displacement, thereby adjusting the tab misalignment of the cell roll so that the tab misalignment (10) is within the standard misalignment range. Then, the tab misalignment of the cell roll is adjusted within a small range through the subsequent winding process to obtain a qualified cell roll. If the tab misalignment does not exceed the standard misalignment, the tab misalignment of the cell roll is adjusted within a small range in the subsequent winding process to obtain a qualified cell roll. Step S6: The battery cell roll on the winding needle is unloaded by the unloading clamping needle mechanism; The feeding clamping needle mechanism includes an inner clamping needle and an outer clamping roller. Step S6 includes: Step S6.1: The inner clamping pin extends into the battery cell roll and opens the battery cell roll, separating the battery cell roll from the winding pin. The winding pin is then pulled out of the battery cell roll. During the process of the inner clamping pin opening the battery cell roll, the remaining misalignment of the cathode electrode and the anode electrode in the battery cell roll is eliminated. Step S6.2: The outer clamping roller clamps the battery cell roll on the outside, and the inner clamping needle is pulled away from the battery cell roll.

2. The cell winding method with adjustable tab misalignment as described in claim 1, characterized in that, Obtaining the tab misalignment of the cathode and anode plates in the battery cell roll includes: The misalignment of the cathode and anode electrodes in the battery cell roll is measured by a CCD vision inspection unit to obtain the numerical value of the misalignment.

3. The cell winding method with adjustable tab misalignment as described in claim 1, characterized in that, Step S1 includes: Step S1.1: Unwind the first layer of diaphragm to the winding needle using the first diaphragm unwinding mechanism. Step S1.2: Unwind the cathode electrode to the winding needle using the cathode electrode unwinding mechanism; Step S1.3: Unwind the second diaphragm to the winding needle using the second diaphragm unwinding mechanism; Step S1.4: Unwind the anode sheet to the winding needle using the anode sheet unwinding mechanism.

4. The cell winding method with adjustable tab misalignment as described in claim 3, characterized in that, Both the first diaphragm unwinding mechanism and the second diaphragm unwinding mechanism include a diaphragm unwinding shaft (5) and a diaphragm guide roller (6). The tension adjustment mechanism (4) is located between the diaphragm guide roller (6) and the winding needle. Step S1.2 includes: The diaphragm unwinding shaft (5) outputs the diaphragm (7), and the diaphragm (7) is wound onto the winding needle after passing through the diaphragm roller (6) and the tension adjusting mechanism (4) in sequence.

5. The cell winding method with adjustable tab misalignment as described in claim 1, characterized in that, The battery cell roll includes an initial battery cell roll (8), and step S2 includes: The winding needle rotates around its own axis to wind together a certain length of the cathode electrode, the anode electrode, and the diaphragm (7) to form the initial battery cell roll (8).

6. The cell winding method with adjustable tab misalignment as described in claim 5, characterized in that, The battery cell roll also includes a shaped battery cell roll (9), the flipping mechanism includes a turntable (3), and the winding needle is located on the turntable (3) at a position off-axis. Step S5 includes: Step S5.1: The turntable (3) rotates around its own axis, driving the winding needle to flip around the axis of the turntable (3), and the winding needle drives the initial battery cell roll (8) to flip around the axis of the turntable (3); Step S5.2: The diaphragm (7) on the initial cell roll (8) is cut by the cutting mechanism to form the shaped cell roll (9).

7. The cell winding method with adjustable tab misalignment as described in claim 6, characterized in that, The turntable (3) is provided with a working position and a feeding position. The winding needle includes a first winding needle (1) and a second winding needle (2). Initially, the first winding needle (1) is located at the working position, and the second winding needle (2) is located at the feeding position. Step S5.1 includes: The turntable (3) rotates around its own axis, driving the first winding needle (1) and the second winding needle (2) to rotate synchronously around the axis of the turntable (3), so that the first winding needle (1) rotates from the working position to the unloading position, and the second winding needle (2) rotates from the unloading position to the working position. The first winding needle (1) drives the initial battery cell roll (8) to rotate from the working position to the unloading position.

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