A pre-lithium battery cell manufacturing method

Abstract

The application discloses a kind of prelithium battery cell manufacturing method, comprising the following steps: S1: first diaphragm, negative pole piece, second diaphragm, positive pole piece are sequentially wound to form roll core semi-finished product along the direction of rotation of winding needle;S2: negative pole piece and positive pole piece are cut according to set length;S3: first lithium sheet is cut to length, and first lithium sheet is sent into composite mechanism, and first diaphragm, first lithium sheet, second diaphragm are sequentially compounded to form composite lithium belt assembly in composite mechanism, when first lithium sheet is sent into composite mechanism, winding needle continues to rotate along the direction of rotation;S4: first diaphragm and second diaphragm are cut, and after subsequent tape sticking, hot pressing, roll core manufacturing is completed.The battery cell manufacturing method completes the compounding of lithium sheet and two diaphragms during the winding process of battery cell, and then the composite lithium belt assembly continues to be wound along with the winding of roll core semi-finished product, which avoids the safety hazard caused by long-term exposure of lithium sheet to air.

Description

Technical Field

[0001] This invention relates to the field of lithium battery manufacturing technology, and in particular to a method for manufacturing a pre-lithium battery cell. Background Technology

[0002] With societal development, the application of electrochemical energy storage devices has garnered increasing attention. However, due to limitations in materials, the initial efficiency of electrochemical energy storage devices is becoming increasingly apparent, making the development of a technology to address this issue an urgent priority.

[0003] Traditional positive electrode lithium replenishment mainly uses lithium compounds as additives. However, the addition of these substances introduces ineffective components, reducing energy density. Negative electrode lithium replenishment primarily uses lithium powder and ultra-thin lithium foil. Lithium particles have large diameters (D50 ≥ 40 micrometers), which are classified as explosive dust and pose a high hazard. Furthermore, lithium is highly reactive, and pre-cut lithium sheets exposed to air for extended periods pose certain safety risks. Summary of the Invention

[0004] Based on the technical problems existing in the background technology, the present invention proposes a method for manufacturing pre-lithium battery cells, in which the composite lithium strip assembly is wound along with the winding of the core semi-finished product, thereby avoiding the safety hazards caused by the long-term exposure of lithium sheets to air.

[0005] The present invention proposes a method for manufacturing a pre-lithium battery cell, comprising the following steps:

[0006] S1: The first diaphragm, negative electrode sheet, second diaphragm, and positive electrode sheet are wound sequentially along the rotation direction of the winding needle to form a core semi-finished product;

[0007] S2: Cut the negative electrode and positive electrode to the set length;

[0008] S3: Cut the first lithium sheet to a fixed length and feed it into the composite mechanism. In the composite mechanism, the three are combined in the order of the first diaphragm, the first lithium sheet, and the second diaphragm to form a composite lithium strip assembly. When the first lithium sheet is fed into the composite mechanism, the winding needle continues to rotate in the rotation direction.

[0009] S4: Cut the first and second diaphragms, and complete the core fabrication after applying tape and hot pressing.

[0010] Furthermore, the core semi-finished product is horizontal in the middle and curved on both sides. In step S3, one or more first lithium sheets are wound on the same core semi-finished product, and the first lithium sheets are sequentially arranged at two opposite middle horizontal positions.

[0011] Furthermore, the substrate of the first lithium sheet is a metal substrate, which is coated with a lithium metal-rich coating on one or both sides and does not contain the coating at the tab. The metal substrate includes one or more of copper, copper alloys, or other negative electrode conductive metal materials.

[0012] Furthermore, the first and second diaphragms are adhesive-coated diaphragms, and the size of the first lithium sheet is no larger than the size of the horizontal plane of the core semi-finished product.

[0013] Furthermore, the composite mechanism is provided with a heating component, the heating temperature of which is 50-100 degrees Celsius.

[0014] Furthermore, the first diaphragm is obtained by unwinding through a first diaphragm feeding mechanism;

[0015] The second diaphragm is obtained by unwinding through the second diaphragm feeding mechanism;

[0016] The negative electrode sheet is obtained by unwinding through a negative electrode sheet feeding mechanism;

[0017] The positive electrode sheet is obtained by unwinding through a positive electrode sheet feeding mechanism;

[0018] The first lithium sheet is obtained by unwinding through a lithium strip feeding mechanism.

[0019] Furthermore, the winding needle is located in the middle, and the first diaphragm feeding mechanism, lithium strip feeding mechanism, negative electrode feeding mechanism, second diaphragm feeding mechanism, and positive electrode feeding mechanism are arranged adjacent to each other in sequence.

[0020] Furthermore, the unwinding ends of the first diaphragm feeding mechanism, the lithium strip feeding mechanism, the negative electrode feeding mechanism, and the second diaphragm feeding mechanism are connected to the composite mechanism, and the unwinding end of the positive electrode feeding mechanism is connected to the winding needle.

[0021] Furthermore, a first cutting mechanism for cutting the first separator, a second cutting mechanism for cutting the second separator, a third cutting mechanism for cutting the negative electrode sheet, and a fourth cutting mechanism for cutting the positive electrode sheet are provided near the winding needle, and a fifth cutting mechanism for cutting the first lithium sheet is provided near the winding needle.

[0022] Furthermore, a clamping and conveying mechanism is provided on one side of the fifth cutting mechanism for conveying the cut first lithium sheet to the composite mechanism.

[0023] The advantages of the pre-lithium battery cell manufacturing method provided by this invention are as follows: In the pre-lithium battery cell manufacturing method provided by this invention, the lithium sheet is composited with two separators during the cell winding process. Then, the composite lithium strip assembly continues to be wound along with the winding of the core semi-finished product, avoiding the safety hazards caused by the lithium sheet being exposed to air for a long time. Simultaneously, before the added lithium sheet participates in the winding, it is first composited with the two separators, ensuring the relative position of the lithium sheet during the manufacturing process. Furthermore, the lithium sheet and separator composite process is synchronized with the continuous winding of the core semi-finished product. During this process, the winding needle rotates continuously, improving the cell winding efficiency. In the subsequent hot pressing process, it completely forms a whole with the battery cell, avoiding positional shifts during subsequent assembly and improving the yield rate of the core manufacturing. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 A schematic cross-sectional view of a pre-lithiated winding core;

[0026] Figure 3 A schematic diagram of a cross-section of another type of pre-lithiated core;

[0027] Among them, 10-first separator feeding mechanism, 20-negative electrode feeding mechanism, 30-second separator feeding mechanism, 40-positive electrode feeding mechanism, 50-lithium strip feeding mechanism, 100-needle winding, 101-first separator, 102-negative electrode, 103-second separator, 104-positive electrode, 200-composite mechanism, 501-first lithium sheet. Detailed Implementation

[0028] The technical solution of the present invention will now be described in detail through specific embodiments. Many specific details are set forth in the following description to provide a thorough understanding of the invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] like Figures 1 to 3 As shown, the present invention proposes a method for manufacturing a pre-lithium battery cell, which includes the following steps:

[0030] S1: The first diaphragm 101, the negative electrode 102, the second diaphragm 103, and the positive electrode 104 are wound sequentially along the rotation direction of the winding needle 100 to form a core semi-finished product;

[0031] For square lithium batteries, the rolled core semi-finished product is horizontal in the middle and curved on both sides, with an appearance of waist shape. The first separator 101 and the second separator 103 are single-sided or double-sided coated separators with a thickness of 12um. The negative electrode 102 and the positive electrode 104 are made of ternary or common battery material systems such as lithium iron phosphate and lithium manganese oxide.

[0032] The number of winding layers of the core semi-finished product can be one, two, or more. In this step, the lithium strip feeding mechanism 50 does not participate in the winding.

[0033] The first diaphragm 101 is obtained by unwinding through the first diaphragm feeding mechanism 10. The first diaphragm unwinding system includes the first diaphragm feeding mechanism 10, the first roller passing mechanism, and the first cutting mechanism arranged in sequence. The first roller passing mechanism is composed of multiple rollers and is equipped with a first correction component and a first tension component. These two components are used to assist in the stable conveying of the first diaphragm 101. The first diaphragm 10 unwound by the first diaphragm feeding mechanism 10 is conveyed by the first roller passing mechanism, wound on the winding needle 100, and cut by the first cutting mechanism when it is unwound to a set length.

[0034] The second diaphragm 103 is obtained by unwinding through the second diaphragm feeding mechanism 30. The second diaphragm unwinding system includes the second diaphragm feeding mechanism 30, the second roller passing mechanism, and the second cutting mechanism arranged in sequence. The second roller passing mechanism is composed of multiple rollers and is equipped with a second correction component and a second tension component. These two components are used to assist in the stable conveying of the second diaphragm 103. The second diaphragm 103 unwound by the second diaphragm feeding mechanism 30 is conveyed by the second roller passing mechanism, wound on the winding needle 100, and cut by the second cutting mechanism when it is unwound to a set length.

[0035] The negative electrode sheet 102 is obtained by unwinding through the negative electrode sheet feeding mechanism 20. The negative electrode sheet unwinding system includes the negative electrode sheet feeding mechanism 20, the third roller passing mechanism, the first shaping mechanism and the third cutting mechanism arranged in sequence. The third roller passing mechanism is composed of multiple rollers. The third roller passing mechanism is equipped with a third correction component and a third tension component. These two components are used to assist in the stable conveying of the negative electrode sheet 102. The negative electrode sheet 102 unwound by the negative electrode sheet feeding mechanism 20 is conveyed by the third roller passing mechanism and shaped by the first shaping mechanism. It is wound on the winding needle 100 and cut by the third cutting mechanism when it is unwound to a set length.

[0036] The positive electrode sheet 104 is obtained by unwinding through the positive electrode sheet feeding mechanism 40. The positive electrode sheet unwinding system includes the positive electrode sheet feeding mechanism 40, the fourth roller passing mechanism, the second shaping mechanism, and the fourth cutting mechanism arranged in sequence. The fourth roller passing mechanism is composed of multiple rollers and is equipped with a fourth correction component and a fourth tension component. These two components are used to assist in the stable conveying of the positive electrode sheet 104. The positive electrode sheet 104 unwound by the positive electrode sheet feeding mechanism 40 is conveyed by the fourth roller passing mechanism and shaped by the second shaping mechanism. It is wound on the winding needle 100 and cut by the fourth cutting mechanism when it is unwound to a set length.

[0037] S2: Cut the negative electrode 102 and the positive electrode 104 to the set length;

[0038] When the negative electrode 102 and the positive electrode 104 are cut, the first separator 101 and the second separator 103 are not cut. That is, the electrode can be completely wound through the separator, which provides a basis for the subsequent thermal bonding of the separator with the lithium sheet.

[0039] S3: Cut the first lithium sheet 501 to a fixed length and feed the first lithium sheet 501 into the composite mechanism. In the composite mechanism 200, the three are composited in the order of the first diaphragm 101, the first lithium sheet 501, and the second diaphragm 103 to form a composite lithium strip assembly. When the first lithium sheet 501 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction.

[0040] The cutting of the first lithium sheet 501 can occur during, before, or after the cutting of the negative electrode 102 and the positive electrode 104. That is, the cutting of the lithium sheet and the cutting of the electrode are two independent cutting processes, and the cutting operations do not affect each other.

[0041] The substrate of the first lithium sheet 501 is a metal substrate, which is coated with a lithium metal-rich coating on one or both sides and does not contain the coating at the electrode tab. The metal substrate includes one or more of copper, copper alloys or other negative electrode conductive metal materials.

[0042] The composite mechanism is equipped with a heating component, and the heating temperature of the heating component is 50-100 degrees. This embodiment is not limited to a specific heat-sealing component structure. The preferred solution is one that can effectively composite the lithium sheet. Two composite mechanisms are described below.

[0043] The first method: The composite mechanism specifically includes a heat-sealing assembly that encapsulates the first lithium sheet 501 around its perimeter. The heat-sealing assembly can be achieved by using a telescopic cylinder to drive rollers, where the rollers are hollow. Hot oil is added to the hollow rollers to achieve thermal bonding. During this process, the unwinding ends of the first diaphragm feeding mechanism 10, the lithium strip feeding mechanism 50, the negative electrode feeding mechanism 20, and the second diaphragm feeding mechanism 30 are connected to the composite mechanism. The unwinding end of the positive electrode feeding mechanism 40 is connected to the winding needle 100. Before the first lithium sheet 501 participates in winding, the first diaphragm feeding mechanism... 10. When the negative electrode feeding mechanism 20 and the second diaphragm feeding mechanism 30 pass through the composite mechanism, the telescopic cylinder retracts and drives the roller to move away from the electrode, so that the first diaphragm feeding mechanism 10, the negative electrode feeding mechanism 20, and the second diaphragm feeding mechanism 30 can feed material to the winding needle 100 without obstruction. After the first lithium sheet 501 participates in the winding, the telescopic cylinder extends and drives the roller to abut against the composite lithium strip assembly. The first lithium sheet 501 is thermally composited by heat sealing to avoid the problem of affecting the lithium replenishment effect of the cell due to the active characteristics of lithium.

[0044] The second method: The composite mechanism specifically includes a heat-sealing roller formed by composited a first lithium sheet 501 and its two sides, a first separator 101 and a second separator 103. The heat-sealing roller can be driven by a servo motor to rotate and driven by a telescopic cylinder to move up and down. The heat-sealing roller has a hollow structure, and hot oil is added to the hollow heat-sealing roller to achieve the thermal composite effect. In this process, the unwinding ends of the first separator feeding mechanism 10, the lithium strip feeding mechanism 50, the negative electrode feeding mechanism 20, and the second separator feeding mechanism 30 are connected to the composite mechanism, and the unwinding end of the positive electrode feeding mechanism 40 is connected to the winding needle 100. Before the first lithium sheet 501 participates in the winding... When the first diaphragm feeding mechanism 10, the negative electrode feeding mechanism 20, and the second diaphragm feeding mechanism 30 pass through the composite mechanism, the telescopic cylinder retracts, driving the heat-sealing roller to move away from the electrode, so that the first diaphragm feeding mechanism 10, the negative electrode feeding mechanism 20, and the second diaphragm feeding mechanism 30 can feed materials to the winding needle 100 without obstruction; after the first lithium sheet 501 participates in the winding, the telescopic cylinder extends, driving the heat-sealing roller to abut against the composite lithium strip assembly, and the servo motor drives the heat-sealing roller to rotate, performing thermal composite on the first lithium sheet 501 through heat sealing, so as to avoid the problem of affecting the lithium replenishment effect of the cell due to the active characteristics of lithium.

[0045] The difference between the two methods is that the first method involves heat-sealing the edges of the first diaphragm feeding mechanism 10 and the second diaphragm feeding mechanism 30, which is equivalent to heat-sealing the first diaphragm feeding mechanism 10 and the second diaphragm feeding mechanism 30 around their perimeter to form a bag, in which the first lithium sheet 501 is placed; the second method involves directly attaching a heat-sealing roller to the top of the stacked first diaphragm feeding mechanism 10, the first lithium sheet 501, and the second diaphragm feeding mechanism 30, and achieving thermal bonding of the first lithium sheet 501 through direct attachment and heat pressing; both methods can achieve effective thermal bonding of the first lithium sheet 501.

[0046] It should be noted that during the encapsulation process of the first lithium sheet 501, one method is to pause the winding of the winding needle 100 and then resume winding after the first lithium sheet 501 is encapsulated. While this method achieves effective thermal bonding of the first lithium sheet 501, it increases the overall cell winding time, affecting the production efficiency of the pre-lithium cell. Another method is to continuously wind the winding needle 100, activating the heat-sealing assembly to thermally bond the first lithium sheet 501 when one end of it is fed into the bonding mechanism 200. This method not only achieves effective thermal bonding but also does not affect the overall cell winding time, thus improving the production efficiency of the pre-lithium cell. For prismatic batteries, to maximize the lithium replenishment effect of the first lithium sheet 501, it is positioned at the horizontal level of the semi-finished core to maximize the lithium replenishment operation of the cell.

[0047] As the first lithium sheet 501 is fed into the composite mechanism 200 after being cut, a clamping and conveying mechanism is provided on one side of the fifth cutting mechanism. The clamping and conveying mechanism can adopt an existing structure, with the clamping and conveying of the first lithium sheet 501 being the preferred solution. The specific structure of the clamping and conveying mechanism is not limited here.

[0048] It should be noted that, in order to effectively replenish lithium on both sides of the square battery, a second lithium sheet 502 is wound around the core semi-finished product at a position away from the first lithium sheet 501. The setting and winding of the second lithium sheet 502 are the same as those of the first lithium sheet 501. At the same time, multiple layers of the first lithium sheet 501 or the second lithium sheet 502 can be set on both sides of the core semi-finished product (the lithium sheet on the same side of the core semi-finished product is used as the first lithium sheet 501 or the second lithium sheet 502).

[0049] The specific arrangement of the structure on which the pre-lithium battery cell is based is as follows: the winding needle 100 is located in the middle, and the first separator feeding mechanism 10, the lithium strip feeding mechanism 50, the negative electrode feeding mechanism 20, the second separator feeding mechanism 30, and the positive electrode feeding mechanism 40 are arranged adjacent to each other in sequence.

[0050] S4: Cut the first diaphragm 101 and the second diaphragm 103, and complete the core fabrication after subsequent tape application and hot pressing.

[0051] The first diaphragm 101 and the second diaphragm 103 are cut by the first cutting mechanism and the second cutting mechanism. The tape application and hot pressing processes can both be achieved using existing core forming structures.

[0052] Through steps S1 to S4, the lithium sheet and the two separators are combined during the battery cell winding process. Then, the composite lithium strip assembly continues to be wound along with the winding core semi-finished product, avoiding the safety hazards caused by the long-term exposure of the lithium sheet to the air. At the same time, before the lithium sheet is added to participate in the winding, it is first combined with the two separators to ensure the relative position of the lithium sheet during the manufacturing process. In addition, the lithium sheet and separator combination process and the continuous winding of the winding core semi-finished product are carried out synchronously. During this process, the winding needle 100 rotates continuously, which improves the battery cell winding efficiency. In the subsequent hot pressing process, it completely forms a whole with the battery cell, avoiding positional displacement during subsequent assembly and improving the pass rate of the winding core manufacturing.

[0053] Steps S1 to S4 are the process of setting lithium sheets on one side of the core semi-finished product. The following describes the process of setting one or more lithium sheets on both sides of the core semi-finished product.

[0054] First embodiment, such as Figure 1 and 2 As shown:

[0055] S11: The first diaphragm 101, the negative electrode 102, the second diaphragm 103, and the positive electrode 104 are wound sequentially along the rotation direction of the winding needle 100 to form a core semi-finished product;

[0056] S12: Cut the negative electrode 102 and the positive electrode 104 to the set length;

[0057] S13: Cut the first lithium sheet 501 to a fixed length and feed the first lithium sheet 501 into the composite mechanism 200. In the composite mechanism 200, the three are composited in the order of the first diaphragm 101, the first lithium sheet 501, and the second diaphragm 103 to form a composite lithium strip assembly. When the first lithium sheet 501 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the first lithium sheet 501 in the horizontal direction of the core semi-finished product.

[0058] S14: Cut the second lithium sheet 502 to a fixed length and feed the second lithium sheet 502 into the composite mechanism 200. In the composite mechanism 200, the three are composited in the order of the first diaphragm 101, the second lithium sheet 502, and the second diaphragm 103 to form a composite lithium strip assembly. When the second lithium sheet 502 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the second lithium sheet 502 on the horizontal direction of the core semi-finished product.

[0059] The first lithium sheet 501 and the second lithium sheet 502 are respectively disposed on the upper and lower horizontal surfaces of the core semi-finished product.

[0060] S15: Cut the first diaphragm 101 and the second diaphragm 103, and complete the core fabrication after subsequent tape application and hot pressing.

[0061] Steps S11 to S15 are used to set a lithium sheet on each side of the semi-finished core.

[0062] Second embodiment, such as Figure 1 and 2 As shown:

[0063] S21: The first diaphragm 101, the negative electrode 102, the second diaphragm 103, and the positive electrode 104 are wound sequentially along the rotation direction of the winding needle 100 to form a core semi-finished product;

[0064] S22: Cut the negative electrode 102 and the positive electrode 104 to the set length;

[0065] S23: Cut the first lithium sheet 501 to a fixed length and feed the first lithium sheet 501 into the composite mechanism 200. In the composite mechanism 200, the three are combined in the order of the first diaphragm 101, the first lithium sheet 501, and the second diaphragm 103 to form a composite lithium strip assembly. When the first lithium sheet 501 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the first lithium sheet 501 in the horizontal direction of the core semi-finished product.

[0066] S24: Cut the second lithium sheet 502 to a fixed length and feed the second lithium sheet 502 into the composite mechanism 200. In the composite mechanism 200, the three are composited in the order of the first diaphragm 101, the second lithium sheet 502, and the second diaphragm 103 to form a composite lithium strip assembly. When the second lithium sheet 502 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the second lithium sheet 502 on the horizontal direction of the core semi-finished product.

[0067] S25: Repeat steps S23 to S24 until one or more first lithium sheets 501 and one or more second lithium sheets 502 are respectively wound together.

[0068] S26: Cut the first diaphragm 101 and the second diaphragm 103, and complete the core fabrication after subsequent tape application and hot pressing.

[0069] Steps S21 to S26 are used to set one or more lithium sheets on both sides of the semi-finished core.

[0070] The third embodiment, such as Figure 1 ,2 As shown in Figure 3:

[0071] S31: The first diaphragm 101, the negative electrode 102, the second diaphragm 103, and the positive electrode 104 are wound sequentially along the rotation direction of the winding needle 100 to form a core semi-finished product;

[0072] S32: Cut the negative electrode 102 and the positive electrode 104 to the set length;

[0073] S33: Cut the first lithium sheet 501 to a fixed length and feed the first lithium sheet 501 into the composite mechanism 200. In the composite mechanism 200, the three are combined in the order of the first diaphragm 101, the first lithium sheet 501, and the second diaphragm 103 to form a composite lithium strip assembly. When the first lithium sheet 501 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the first lithium sheet 501 in the horizontal direction of the core semi-finished product.

[0074] S34: Cut the second lithium sheet 502 to a fixed length and feed the second lithium sheet 502 into the composite mechanism 200. In the composite mechanism 200, the three are composited in the order of the first diaphragm 101, the second lithium sheet 502, and the second diaphragm 103 to form a composite lithium strip assembly. When the second lithium sheet 502 is fed into the composite mechanism 200, the winding needle 100 continues to rotate in the rotation direction. The winding needle 100 drives the composite lithium strip assembly to rotate half a turn to wind the second lithium sheet 502 on the horizontal direction of the core semi-finished product.

[0075] S35: The negative electrode 102 is fed between the first separator 101 and the core semi-finished product after step S34, and the positive electrode 104 is fed between the second separator 103 and the first separator 101. Steps S33 to S34 are repeated until one or more first lithium sheets 501 and one or more second lithium sheets 502 are respectively composite wound.

[0076] S36: Cut the first diaphragm 101 and the second diaphragm 103, and complete the core fabrication after subsequent tape application and hot pressing.

[0077] Steps S31 to S36 are used to set one or more lithium sheets on both sides of the semi-finished core.

[0078] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for manufacturing a pre-lithium battery cell, characterized in that, Includes the following steps: S1: The first diaphragm (101), the negative electrode (102), the second diaphragm (103), and the positive electrode (104) are wound sequentially along the rotation direction of the winding needle (100) to form a core semi-finished product; S2: Cut the negative electrode (102) and the positive electrode (104) to the set length; S3: Cut the first lithium sheet (501) to a fixed length and feed the first lithium sheet (501) into the composite mechanism (200). In the composite mechanism (200), the three are combined in the order of the first diaphragm (101), the first lithium sheet (501), and the second diaphragm (103) to form a composite lithium strip assembly. When the first lithium sheet (501) is fed into the composite mechanism (200), the winding needle (100) continues to rotate in the rotation direction. S4: Cut the first diaphragm (101) and the second diaphragm (103), and complete the core production after subsequent tape application and hot pressing.

2. The method for manufacturing a pre-lithium battery cell according to claim 1, characterized in that, The core semi-finished product is horizontal in the middle and curved on both sides. In step S3, one or more first lithium sheets (501) are wound on the same core semi-finished product. The first lithium sheets (501) are arranged in sequence at two opposite middle horizontal positions.

3. The method for manufacturing a pre-lithium battery cell according to claim 1, characterized in that, The substrate of the first lithium sheet (501) is a metal substrate, which is coated with a lithium metal-rich coating on one or both sides and does not contain the coating at the tab. The metal substrate includes one or more of copper, copper alloy or other negative electrode conductive metal materials.

4. The method for manufacturing a pre-lithium battery cell according to claim 2, characterized in that, The first diaphragm (101) and the second diaphragm (103) are coated diaphragms, and the size of the first lithium sheet (501) is not greater than the size of the horizontal plane of the core semi-finished product.

5. The method for manufacturing a pre-lithium battery cell according to claim 1, characterized in that, The composite mechanism is equipped with a heating component, and the heating temperature of the heating component is 50-100 degrees Celsius.

6. The method for manufacturing a pre-lithium battery cell according to claim 1, characterized in that, The first diaphragm (101) is obtained by unwinding through the first diaphragm feeding mechanism (10); The second diaphragm (103) is obtained by unwinding through the second diaphragm feeding mechanism (30); The negative electrode sheet (102) is obtained by unwinding through the negative electrode sheet feeding mechanism (20); The positive electrode sheet (104) is obtained by unwinding through the positive electrode sheet feeding mechanism (40); The first lithium sheet (501) is obtained by unwinding through the lithium strip feeding mechanism (50).

7. The method for manufacturing a pre-lithium battery cell according to claim 6, characterized in that, The winding needle (100) is located in the middle, and the first diaphragm feeding mechanism (10), the lithium strip feeding mechanism (50), the negative electrode feeding mechanism (20), the second diaphragm feeding mechanism (30), and the positive electrode feeding mechanism (40) are arranged adjacent to each other in sequence.

8. The method for manufacturing a pre-lithium battery cell according to claim 7, characterized in that, The unwinding ends of the first diaphragm feeding mechanism (10), the lithium strip feeding mechanism (50), the negative electrode feeding mechanism (20), and the second diaphragm feeding mechanism (30) are connected to the composite mechanism, and the unwinding end of the positive electrode feeding mechanism (40) is connected to the winding needle (100).

9. The method for manufacturing a pre-lithium battery cell according to claim 8, characterized in that, A first cutting mechanism for cutting the first separator (101), a second cutting mechanism for cutting the second separator (103), a third cutting mechanism for cutting the negative electrode (102), and a fourth cutting mechanism for cutting the positive electrode (104) are provided near the winding needle (100), and a fifth cutting mechanism for cutting the first lithium sheet (501) is provided near the winding needle (100).

10. The method for manufacturing a pre-lithium battery cell according to claim 9, characterized in that, The fifth cutting mechanism is provided with a gripping and conveying mechanism on one side for conveying the cut first lithium sheet (501) to the composite mechanism (200).

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