Lithium battery pole piece pre-lithium composite belt, preparation equipment and method

Abstract

The application discloses a kind of lithium battery pole piece pre-lithium composite tape, preparation equipment and method, belong to lithium battery technical field, pre-lithium composite tape, including substrate, substrate includes first area and two sides second area, first area is between two second areas;Second area is continuously coated with lithium layer, first area is intermittently coated with lithium layer.Preparation equipment, including lithium fusion coating mechanism, lithium fusion coating mechanism includes lithium fusion coating bin, lithium fusion coating bin includes middle bin and side bin on the two sides of middle bin, the side of middle bin and side bin towards substrate is provided with lithium coating hole;Side bin is continuously coated with lithium to substrate, and middle bin is intermittently coated with lithium to substrate.Preparation method: motor drives middle bin rotation, middle bin rotation makes lithium liquid level lower than lithium coating hole and middle lithium flow hole and side lithium flow hole are aligned, realize that substrate middle part is intermittently coated.The application can make that substrate surface both sides are coated with lithium and middle part is not coated with lithium, save resources and avoid to cause security risk.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and more specifically, to a pre-lithium composite strip for lithium battery electrodes, its preparation equipment, and a method. Background Technology

[0002] During the first charge and discharge of a lithium-ion battery, the organic electrolyte will be reduced and decomposed on the surface of the negative electrode such as graphite, forming a solid electrolyte interphase (SEI) film. This permanently consumes a large amount of lithium from the positive electrode, resulting in a low coulombic efficiency (ICE) for the first cycle, which reduces the capacity, energy density and lifespan of the lithium-ion battery.

[0003] "Pre-lithiation" refers to adding lithium to the inside of a lithium-ion battery before it is put into operation to replenish lithium ions, thereby offsetting the irreversible lithium loss caused by the formation of the SEI film and improving the battery's total capacity, energy density, and cycle life.

[0004] There is relevant research on "pre-lithiation" in the prior art. For example, Chinese patent document with publication number CN113964374A and publication date of January 21, 2022 discloses a pre-lithiation device and its pre-physicochemical method for electrode sheets. The rotation of the transfer roller of the pre-lithiation device causes the lithium layer on the outer surface of the transfer roller corresponding to the molten lithium liquid to be recovered by the melting tank after passing through the lithium rolling unit. The pre-lithiation has good uniformity.

[0005] Existing technologies also employ physical pressing of lithium strips and copper or aluminum foil. For example, Chinese patent document CN114103386A, published on March 1, 2022, discloses a lithium strip calendering apparatus, a lithium-copper double-sided composite apparatus, and a lithium-copper double-sided composite method. In this method, the lithium strip is calendered to thin it, with both the upper and lower calendering rollers protected by a protective film during calendering. After calendering, a traction film is applied to the lithium strip, and then it is wound up. The lithium strip and copper foil are then double-sided composited, and the traction film is removed before winding. The lithium-copper double-sided composite method in this application, which first calenders and thins the lithium strip before composite formation, reduces the possibility of lithium strip deformation. Simultaneously, the traction film reduces the possibility of lithium strip sticking to the rollers.

[0006] While the lithiation equipment and methods described in the two patent documents offer certain advantages, they also have drawbacks. For example, the lithiation equipment has a relatively complex structure and low precision, and the lithium layer in the produced copper-lithium or aluminum-lithium composite strips is planar, covering the entire surface of the composite strip. When using copper-lithium or aluminum-lithium composite strips with planar lithium layers for pre-lithiation, lithium ions are significantly consumed at the edges of the strip, while almost none are consumed in the middle, resulting in significant lithium residue. This not only wastes resources but also poses serious battery safety hazards. Summary of the Invention

[0007] 1. The technical problem that the invention aims to solve.

[0008] In addressing the problem that existing technologies using copper-lithium composite strips or aluminum-lithium composite strips with planar lithium layers for pre-lithiation result in significant lithium ion consumption at the edges of the strip while almost none is consumed in the middle, leaving noticeable lithium residue, this invention proposes a lithium battery electrode pre-lithiation composite strip. The substrate has continuous lithium coating layers on both sides and intermittently spaced lithium coating layers in the middle. Therefore, the lithium layers at the edges of the substrate can be used for pre-lithiation consumption, while the absence of lithium coating in the middle prevents lithium residue, saving resources and avoiding safety hazards.

[0009] This invention also proposes a lithium battery electrode pre-lithiation composite strip preparation equipment, which can prepare a composite strip with lithium coating on both sides of the substrate surface and no lithium coating in the middle. Therefore, the lithium layer on both sides of the composite strip can be consumed during pre-lithiation, while the absence of lithium coating in the middle will not produce lithium strip residue, thus saving resources and avoiding safety hazards.

[0010] This invention also proposes a method for preparing pre-lithium composite strips for lithium-ion batteries, which uses the aforementioned equipment for preparing pre-lithium composite strips for lithium-ion batteries.

[0011] 2. Technical Solution

[0012] To achieve the above objectives, the present invention provides a lithium battery electrode pre-lithiation composite strip, comprising a substrate, the substrate comprising a first region and two second regions on both sides, the first region being located between the two second regions; the second regions are continuously coated with a lithium layer, and the first region is intermittently coated with a lithium layer.

[0013] The present invention also provides a lithium battery electrode pre-lithiation composite strip preparation device, including a lithium melting coating mechanism, which applies lithium to the substrate; the lithium melting coating mechanism includes a lithium melting coating chamber, which includes a middle chamber and side chambers attached to both sides of the middle chamber, and both the middle chamber and the side chambers are provided with lithium coating holes on the side facing the substrate; the side chambers apply lithium continuously to the substrate, and the middle chamber applies lithium intermittently to the substrate.

[0014] Furthermore, a motor is provided on one side of the intermediate compartment. The output end of the motor is connected to the intermediate compartment through a connecting shaft and a coupling to control the rotation of the intermediate compartment. The rotation of the intermediate compartment causes the lithium coating holes of the intermediate compartment to deviate from the substrate, thereby realizing the intermittent lithium coating of the substrate by the intermediate compartment.

[0015] Furthermore, the intermediate chamber is equipped with a partition that divides the intermediate chamber into a lithium melting section and a lithium coating section. The lithium coating hole is located on one side of the lithium coating section, and the lithium melting section has a feed inlet on one side.

[0016] Furthermore, one end of the partition is seamlessly connected to the inner wall of the intermediate chamber, and the other end is rotatably connected to the baffle plate; the baffle plate rotates unidirectionally toward the lithium coating section so that the lithium liquid flows unidirectionally from the lithium melting section to the lithium coating section.

[0017] Furthermore, the intermediate chamber is cylindrical, and the chamber wall is a sandwich vacuum structure. A heating device is installed inside the sandwich for melting lithium. Intermediate lithium flow holes are provided on both sides of the intermediate chamber, and the intermediate lithium flow holes are located in the lithium coating section. Side lithium flow holes are provided on the side of the side chamber that is in contact with the intermediate chamber. The intermediate chamber is rotated so that the intermediate lithium flow holes and the side lithium flow holes coincide, so that the lithium liquid flows from the intermediate chamber into the side chamber.

[0018] Furthermore, a vacuum hole is provided on the top of the side compartment, and the vacuum hole is connected to a vacuum pumping device through a vacuum pipe.

[0019] Furthermore, it also includes an unwinding mechanism, which includes a substrate, an air shaft, and a first guide roller. The substrate is sleeved on the air shaft, and the first guide roller is disposed between the air shaft and the lithium melting coating mechanism to maintain the uniform tension of the substrate.

[0020] Furthermore, it also includes a calendering mechanism, a cutting mechanism, and a receiving mechanism. The calendering mechanism calenders the lithium-coated substrate transferred from the lithium melting and coating mechanism, the cutting mechanism cuts the calendered substrate, and the receiving mechanism collects the cut substrate.

[0021] This invention also provides a method for preparing a pre-lithiation composite strip for lithium-ion battery electrodes. The method utilizes the aforementioned equipment for preparing the pre-lithiation composite strip for lithium-ion battery electrodes. The substrate reaches below the lithium melting coating chamber, and the molten lithium liquid is coated through the lithium coating holes. A motor regularly drives the intermediate chamber to rotate. The lithium liquid level is controlled by the speed of lithium melting, ensuring that when the intermediate chamber rotates, the lithium liquid level is below the lithium coating holes and the intermediate and side lithium flow holes are aligned, achieving intermittent coating of the first region in the middle of the substrate. When the intermediate and side lithium flow holes are aligned, lithium liquid flows from the intermediate chamber into the side chamber to replenish the lithium liquid lost in the side chamber.

[0022] 3. Beneficial effects

[0023] Compared with existing known technologies, the technical solution provided by this invention has the following beneficial effects:

[0024] (1) A lithium battery electrode pre-lithiation composite strip of the present invention has continuous lithium coating layers on both sides of the composite strip substrate and intermittent lithium coating layers in the middle. Therefore, the lithium layers on both sides of the substrate can be consumed during pre-lithiation, while the absence of lithium coating in the middle will not produce lithium strip residue, thus saving resources and avoiding safety hazards.

[0025] (2) The present invention provides a lithium battery electrode pre-lithiation composite strip preparation equipment, wherein the intermediate chamber intermittently applies lithium to the substrate, and the side chambers on both sides of the intermediate chamber continuously apply lithium, thereby preparing a composite strip with lithium applied to both sides of the substrate surface and no lithium applied in the middle. Therefore, the lithium layer on both sides of the composite strip can be used for consumption during pre-lithiation to replenish lithium ions, and the absence of lithium applied in the middle will not produce lithium strip residue, thus saving resources and avoiding safety hazards.

[0026] (3) A lithium battery electrode pre-lithiation composite strip preparation device of the present invention, wherein a partition divides the intermediate chamber into a lithium melting section and a lithium coating section, and a flow baffle can control the lithium liquid to flow unidirectionally from the lithium melting section to the lithium coating section, while preventing the lithium liquid from flowing back to the lithium melting section when the intermediate chamber rotates. The chamber wall of the intermediate chamber is a sandwich vacuum structure, and a heating device is installed inside the sandwich to melt the lithium material to form lithium liquid. The intermediate lithium flow hole of the intermediate chamber and the side lithium flow hole of the side chamber can overlap when the intermediate chamber rotates to a certain position, so that the lithium liquid inside the intermediate chamber can flow into the side chamber to compensate for the loss of lithium coating in the side chamber. The vacuum hole can provide a vacuum working environment for the side chamber through a vacuum pumping device.

[0027] (4) The lithium battery electrode pre-lithiation composite strip preparation equipment of the present invention realizes continuous production of copper-lithium composite strips and aluminum-lithium composite strips through the continuous operation of the unwinding mechanism, the lithium melting and coating mechanism, the calendering mechanism, the cutting mechanism, and the receiving mechanism. The thickness of the copper-lithium composite strip or aluminum-lithium composite strip is adjusted by the speed and the amount of lithium coating to ensure the lithium content in the composite strip per unit area. At the same time, it avoids the multiple rolling processes of traditional pre-lithiation pressing equipment. Only one rolling process is needed to ensure product consistency, which maximizes the preservation of the original state of the substrate and does not increase or greatly increases the deformation of the substrate, so that the lithium strip and the substrate can better adhere and improve the composite effect.

[0028] (5) The present invention provides a method for preparing a lithium battery electrode pre-lithiation composite strip. The rotation of the intermediate chamber simultaneously aligns the intermediate lithium flow hole and the side lithium flow hole, enabling intermittent coating of the middle part of the substrate. This achieves "U"-shaped lithium coating to meet actual needs. Therefore, the lithium layer on both sides of the substrate can be consumed during pre-lithiation, while the absence of lithium coating in the middle will prevent the generation of lithium strip residue, thus saving resources and avoiding safety hazards. Attached Figure Description

[0029] The dimensions and scales in the accompanying drawings do not represent the actual dimensions and scales of the product. The drawings are for illustrative purposes only, and some non-essential elements or features have been omitted for clarity.

[0030] Figure 1 This is a schematic diagram of the structure of the lithium battery electrode pre-lithium composite strip preparation equipment according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure of the lithium melting coating chamber according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the intermediate compartment according to an embodiment of the present invention;

[0033] Figure 4 This is a schematic diagram of the side compartment according to an embodiment of the present invention;

[0034] Figure 5 This is a schematic diagram of the rolling mechanism according to an embodiment of the present invention;

[0035] Figure 6 This is a schematic diagram of the structure of the pre-lithium composite strip of the lithium battery electrode according to an embodiment of the present invention.

[0036] Explanation of the labels in the diagram:

[0037] 10. Unwinding mechanism; 101. Substrate; 102. Air shaft; 103. First guide roller; 1011. First region; 1012. Second region; 1013. Lithium layer; 1014. Clamping part;

[0038] 20. Lithium melting and coating mechanism; 201. Coating roller; 202. Intermediate chamber; 203. Feed inlet; 204. Side chamber; 205. Connecting shaft; 206. Motor; 207. Coupling; 208. Vacuum hole; 209. Partition plate; 210. Intermediate lithium flow hole; 211. Lithium coating hole; 212. Lithium liquid; 213. Side lithium flow hole; 214. Heating plate; 215. Baffle plate;

[0039] 30. Calendering mechanism; 301. Upper pressure roller; 302. Lower pressure roller; 303. Spray oil tank; 304. Scraper; 305. Waste collection plate; 306. Second pass roller; 307. Encoding roller;

[0040] 40. Cutting mechanism; 401. Die-cutting die; 402. Cutting blade;

[0041] 50. Receiving mechanism; 501. Robotic arm; 502. Receiving platform; 503. Receiving clip. Detailed Implementation

[0042] To further understand the content of this invention, a detailed description of the invention is provided in conjunction with the accompanying drawings and embodiments. The description herein is merely a preferred embodiment of the invention; those skilled in the art can conceive of other ways to implement the invention based on the preferred embodiments, and such other ways also fall within the scope of this invention.

[0043] In the description of this invention, it should be noted that the terms "center," "middle," "upper," "lower," "left," "right," "inner," "outer," "top," "bottom," "side," "vertical," and "horizontal," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and 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, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0044] Example

[0045] Reference Figures 1-5 This embodiment provides a lithium battery electrode pre-lithium composite strip preparation equipment, including an unwinding mechanism 10, a lithium melting and coating mechanism 20, a rolling mechanism 30, a cutting mechanism 40, and a receiving mechanism 50. Through the continuous operation of the above mechanisms, continuous production of copper-lithium composite strips and aluminum-lithium composite strips is realized.

[0046] Specifically, in this embodiment, as follows: Figure 1 As shown, the unwinding mechanism 10 includes a substrate 101, an air shaft 102, and a first guide roller 103. The substrate 101 is sleeved on the air shaft 102, and the first guide roller 103 is disposed between the air shaft 102 and the lithium melting coating mechanism 20, maintaining the uniform tension of the substrate 101 through the first guide roller 103. It should be noted that the air shaft 102 can expand and contract by inflating and deflating to maintain the tension and relaxation of the substrate 101. The number of first guide rollers 103 is 3 to 6, configured according to the size of the equipment space, and is used for tension and stretching control of the substrate 101. The substrate 101 can be copper foil, aluminum foil, copper-plastic composite current collector, or aluminum-plastic composite current collector.

[0047] In this embodiment, as Figure 2 , Figure 3 and Figure 4As shown, the lithium melting coating mechanism 20 includes a coating roller 201 and a lithium melting coating chamber, wherein the lithium melting coating chamber includes a central chamber 202 and side chambers 204. There are two side chambers 204, located on both sides of the central chamber 202 and arranged symmetrically, closely fitting the central chamber 202. The top of the side chambers 204 is designed with a vacuum hole 208 for vacuum requirements during production. The central chamber 202 is cylindrical, and its walls are a sandwich vacuum structure. A heating device, typically a heating plate 214, is installed inside the sandwich for lithium melting. The walls of the side chambers 204 are also equipped with heating plates 214 to maintain the molten lithium 212. The feed inlet 203 is located above the central chamber 202 and features an embedded sealing ring design to ensure the airtightness of the entire lithium melting coating mechanism 20 after feeding. The motor 206 is located on one side of the intermediate compartment 202 and is connected to the intermediate compartment 202 via a connecting shaft 205 and a coupling 207, used to control the rotation of the intermediate compartment 202. A partition 209 is installed inside the intermediate compartment 202, with one end seamlessly connected to the inner wall of the intermediate compartment 202 and the other end rotatably connected to a baffle plate 215. The baffle plate 215 can rotate counterclockwise but not clockwise, ensuring that the lithium liquid 212 does not flow back above the partition plate 209 when the intermediate compartment 202 rotates. A lithium coating hole 211 is designed at the bottom of the intermediate compartment 202 for coating the lithium liquid 212. A central lithium flow hole 210 is designed on each of the two sides, which aligns with the side lithium flow holes 213 when the intermediate compartment 202 rotates, ensuring that the lithium liquid 212 flows from the intermediate compartment 202 into the side compartment 204. The bottom of the side compartment 204 also has a lithium coating hole 211, enabling simultaneous lithium coating on both sides and in the middle.

[0048] It should be noted that the rotation of the intermediate chamber 202 causes the lithium coating hole 211 of the intermediate chamber 202 to deviate from the substrate 101, so that the intermediate chamber 202 intermittently applies lithium to the substrate 101, while the side chambers 204 on both sides of the intermediate chamber 202 continuously apply lithium, so that the surface of the substrate 101 is coated with lithium on both sides but not in the middle. Therefore, the lithium layer 1013 on both sides of the substrate 101 can be used for consumption during pre-lithiation, while the absence of lithium coating in the middle will not produce lithium strip residue, thus saving resources and avoiding safety hazards.

[0049] It is worth noting that intermittent lithium coating of the intermediate chamber 202 can also be achieved in other ways, such as by using a mechanism that periodically seals the lithium coating holes 211 of the intermediate chamber 202, which can also achieve intermittent lithium coating of the intermediate chamber 202. Therefore, there is no single way to achieve intermittent lithium coating.

[0050] Furthermore, in this embodiment, the sum of the lengths of the baffle plate 215 and the partition plate 209 is greater than the inner diameter of the intermediate chamber 202. Due to the position of the baffle plate 215, it can only rotate counterclockwise and not clockwise. Therefore, the lithium liquid 212 can only flow from the melting lithium section above the partition plate 209 into the coating lithium section below. The position of the baffle plate 215 can also be opposite to that in this embodiment. In this case, the baffle plate 215 can only rotate clockwise and not counterclockwise, which also ensures that the lithium liquid 212 can only flow from the melting lithium section above the partition plate 209 into the coating lithium section below.

[0051] In this embodiment, as Figure 1 and Figure 5 As shown, the calendering mechanism 30 includes an upper pressure roller 301, a lower pressure roller 302, a spray oil tank 303, a scraper 304, a waste collection plate 305, a second pass roller 306, and a coding roller 307. The upper pressure roller 301 and lower pressure roller 302 are cylindrical rollers of the same material and size, installed vertically, with a diameter of 200mm to 400mm. The gap and pressure between the two rollers are adjustable. They calender the coated composite strip to ensure consistent thickness. The spray oil tank 303 is installed on the feed side to spray oil onto the upper pressure roller 301 to prevent lithium strip from sticking to the roller. The scraper 304 and waste collection plate 305 are installed on the discharge side of the upper pressure roller 301 for cleaning lithium residue. The second pass roller 306 maintains even tension on the composite strip. The coding roller 307 is used for production counting to ensure consistent cutting dimensions.

[0052] In this embodiment, refer to Figure 1 The cutting mechanism 40 includes a die-cutting mold 401 and a cutting blade 402. The die-cutting mold 401 is used for forming the tabs of the coated and calendered product. The cutting blade 402 is used to cut each composite tape unit, and the surface roughness of the cutting blade 402 needs to reach the Ra 0.025um level or higher.

[0053] In this embodiment, refer to Figure 1 The receiving mechanism 50 includes a robotic arm 501, a receiving platform 502, and a receiving clip 503. The robotic arm 501 is designed as a vacuum non-marking suction cup to ensure no damage to the product. The robotic arm 501 picks up the cut composite tape unit that has arrived on the receiving platform 502 and sends it to the receiving clip 503 to complete the entire production process.

[0054] This embodiment also provides a method for preparing a pre-lithium composite strip for lithium battery electrodes, the specific steps of which are as follows:

[0055] S1. Place lithium ingots or lithium strips into the intermediate chamber 202 through the feed port 203. The motor 206 drives the intermediate chamber 202 to rotate counterclockwise by about 30°, so that the intermediate lithium flow hole 210 and the side lithium flow hole 213 are aligned. Turn on the vacuum to make the negative pressure inside the lithium melting coating chamber reach below -50Pa. Turn on the heating to make the temperature reach above 220°C.

[0056] S2. When the lithium ingot or lithium strip is melted, start the equipment. The substrate 101 passes through the first roller 103 and reaches the bottom of the lithium melting coating chamber. The melted lithium liquid 212 is coated with lithium through the lithium coating hole 211.

[0057] S3. To achieve the purpose of "U"-shaped lithium coating, the motor 206 needs to regularly drive the intermediate chamber 202 to rotate counterclockwise. The liquid level of the lithium liquid 212 is controlled by the speed of lithium melting. When the intermediate chamber 202 rotates, the liquid level of the lithium liquid 212 is lower than the lithium coating hole 211, and the intermediate flow lithium hole 210 and the side flow lithium hole 213 are aligned to ensure that the middle part of the composite strip is intermittently coated. When the intermediate flow lithium hole 210 and the side flow lithium hole 213 are aligned, the lithium liquid 212 flows from the intermediate chamber 202 into the side chamber 204 to replenish the lithium liquid 212 loss in the side chamber 204.

[0058] S4. Motor 206 drives intermediate chamber 202 to reciprocate, realizing uninterrupted production. The lithium-coated substrate 101 reaches the calendering mechanism 30 and passes between the upper pressure roller 301 and the lower pressure roller 302. The pressure of the pressure roller is controlled to calender the composite belt to achieve the target thickness.

[0059] S5. The calendered composite strip passes through the coding roller 307 to the cutting mechanism 40. The die-cutting mold 401 forms tabs on the composite strip, and the cutting blade 402 cuts the continuously coated composite strip into independent units.

[0060] S6. After the composite belt of the independent unit arrives at the receiving platform 502, the robot arm 501 picks up the independent unit and puts it into the receiving clip 503, and continues to operate to complete the entire production process.

[0061] Using the above equipment and methods for preparing pre-lithium composite strips for lithium-ion battery electrodes, it is possible to obtain, as follows: Figure 6 The lithium battery electrode pre-lithiation composite strip shown includes a substrate 101, which includes a first region 1011 and two second regions 1012 on both sides. The first region 1011 is located between the two second regions 1012, that is, in the middle part of the substrate 101. The second regions 1012 are continuously coated with a lithium layer 1013 through side compartments 204, and the first region 1011 is intermittently coated with a lithium layer 1013 through a middle compartment 202. The lithium layer 1013 is generally U-shaped. A clamping part 1014 is also provided at one end of the substrate 101 to facilitate the clamping of the composite strip.

[0062] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. A lithium battery electrode pre-lithiation composite strip preparation apparatus, comprising a lithium melting coating mechanism (20), wherein the lithium melting coating mechanism (20) applies lithium to the pre-lithiation composite strip; characterized in that, The pre-lithiation composite strip includes a substrate (101), the substrate (101) includes a first region (1011) and two second regions (1012) on both sides, the first region (1011) is located between the two second regions (1012); the second regions (1012) are continuously coated with a lithium layer (1013), and the first region (1011) is intermittently coated with a lithium layer (1013); the lithium melting coating mechanism (20) includes a lithium melting coating chamber, the lithium melting coating chamber includes a middle chamber (202) and side chambers (204) attached to both sides of the middle chamber (202), the middle chamber (202) and the side chambers (204) are attached to both sides of the middle chamber (202). 04) Lithium coating holes (211) are provided on one side facing the substrate (101); the side chamber (204) continuously applies lithium to the substrate (101), and the middle chamber (202) applies lithium intermittently to the substrate (101); a motor (206) is provided on one side of the middle chamber (202), and the output end of the motor (206) is connected to the middle chamber (202) through a connecting shaft (205) and a coupling (207) to control the rotation of the middle chamber (202). The rotation of the middle chamber (202) causes the lithium coating holes (211) of the middle chamber (202) to deviate from the substrate (101), thereby realizing the intermittent lithium application of the middle chamber (202) to the substrate (101).

2. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 1, characterized in that, The intermediate chamber (202) is provided with a partition (209) inside, which divides the intermediate chamber (202) into a lithium melting section and a lithium coating section. The lithium coating hole (211) is located on one side of the lithium coating section, and the lithium melting section has a feed inlet (203) on one side.

3. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 2, characterized in that, One end of the partition (209) is seamlessly connected to the inner wall of the intermediate chamber (202), and the other end is rotatably connected to the baffle plate (215); the baffle plate (215) rotates unidirectionally toward the lithium coating section so that the lithium liquid (212) flows unidirectionally from the lithium melting section to the lithium coating section.

4. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 2, characterized in that, The intermediate chamber (202) is cylindrical, and the chamber wall of the intermediate chamber (202) is a sandwich vacuum structure. A heating device is installed inside the sandwich for melting lithium. Intermediate lithium flow holes (210) are provided on both sides of the intermediate chamber (202), and the intermediate lithium flow holes (210) are located in the lithium coating section. The side compartment (204) and the middle compartment (202) are fitted with a side lithium flow hole (213). The middle compartment (202) is rotated so that the middle lithium flow hole (210) and the side lithium flow hole (213) overlap, so that the lithium liquid (212) flows from the middle compartment (202) into the side compartment (204).

5. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 4, characterized in that, The top of the side compartment (204) is provided with a vacuum hole (208), which is connected to a vacuum pumping device through a vacuum pipe.

6. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 1, characterized in that, It also includes an unwinding mechanism (10), which includes a substrate (101), an air shaft (102) and a first guide roller (103). The substrate (101) is sleeved on the air shaft (102), and the first guide roller (103) is disposed between the air shaft (102) and the lithium melting coating mechanism (20) to maintain the average tension of the substrate (101).

7. The lithium battery electrode pre-lithiation composite strip preparation equipment according to claim 1, characterized in that, It also includes a calendering mechanism (30), a cutting mechanism (40) and a receiving mechanism (50). The calendering mechanism (30) calenders the lithium-coated substrate (101) transferred from the lithium melting coating mechanism (20), the cutting mechanism (40) cuts the calendered substrate (101), and the receiving mechanism (50) collects the cut substrate (101).

8. A method for preparing a pre-lithium composite strip for lithium battery electrodes, characterized in that, The lithium battery electrode pre-lithiation composite strip preparation equipment according to any one of claims 1-7 is used. The substrate (101) reaches below the lithium melting coating chamber. The molten lithium liquid (212) is coated with lithium through the lithium coating hole (211). The motor (206) drives the intermediate chamber (202) to rotate regularly. The liquid level of the lithium liquid (212) is controlled by the lithium melting speed. When the intermediate chamber (202) rotates, the liquid level of the lithium liquid (212) is lower than the lithium coating hole (211) and the intermediate lithium flow hole (210) and the side lithium flow hole (213) are aligned. The first area (1011) of the middle part of the substrate (101) is intermittently coated. When the intermediate lithium flow hole (210) and the side lithium flow hole (213) are aligned, the lithium liquid (212) flows from the intermediate chamber (202) into the side chamber (204) to replenish the lithium liquid (212) loss of the side chamber (204).

Images