Lithium battery coating method, coating system and lithium battery

Abstract

The invention discloses a lithium battery coating method which comprises the following steps: S1, providing electrode slurry, arranging a stripe filling needle nozzle, enabling the stripe filling needle nozzle to form a micro-concave structure, conveying the electrode slurry into a coating system, and enabling the electrode slurry to respectively enter a coating die head and the stripe filling needle nozzle; s2, performing multi-stage filtration on the electrode slurry entering the stripe filling needle nozzle, and controlling the particle size of the electrode slurry; s3, the contact height of the stripe filling needle nozzle and the coating section is adjusted, so that a difference value is formed between the height from the stripe filling needle nozzle to the coating section and the height from the coating die head to the coating section; and S4, a current collector is synchronously input into the coating roller to be matched with the lower die head and the stripe filling needle nozzle for coating operation, so that a stripe filling coating is formed on the surface of the current collector. The invention further provides a coating system and a lithium battery, the linear filling coating is formed on the surface of the current collector through coating, and the performance of the lithium ion battery can be improved while the effect in the original technical scheme is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of lithium battery technology, and in particular to a lithium battery coating method, coating system and lithium battery. Background Technology

[0002] The continuous development of lithium-ion batteries in multiple directions, such as high voltage, high rate, and high safety, has posed more severe challenges to electrode structure design. The coating technology currently widely used is still limited to single and simple coating methods, making it difficult to achieve multi-region, gradient, or microstructure controllable coating designs. Therefore, it cannot meet the electrode performance requirements of high energy density and high power output. To achieve more complex electrode structures, such as improving ion transport efficiency or mitigating volume changes during charging and discharging, additional auxiliary process equipment is usually required. For example, laser etching technology can be used to precisely create holes or scribing lines on the electrode surface, which can effectively improve electrolyte wettability and lithium-ion diffusion kinetics.

[0003] However, these additional processes not only significantly increase equipment investment and production costs, but also introduce new process variables, placing higher demands on coating consistency, drying process and rolling process, which may adversely affect the overall yield, cycle life and safety of the battery cells. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a lithium battery coating method, coating system and lithium battery. This invention achieves the formation of a linear filling coating on the surface of the current collector. In addition to ensuring the effect of the original technical solution, it can also fundamentally improve the performance of lithium-ion batteries through the effect of the coating.

[0005] To achieve the above objectives, the present invention provides a lithium battery coating method, a coating system, and a lithium battery, comprising the following steps:

[0006] S1. Provide electrode paste and set stripe filling nozzle to form a micro-concave structure, and deliver the electrode paste to the coating system so that the electrode paste enters the coating die head and the stripe filling nozzle respectively.

[0007] S2. Perform multi-stage filtration on the electrode slurry entering the stripe filling nozzle to control the particle size of the electrode slurry.

[0008] S3. Adjust the contact height between the stripe filling nozzle and the coating section so that the height of the stripe filling nozzle to the coating section is different from the height of the coating die to the coating section.

[0009] S4. Simultaneously, the current collector is fed into the coating roller and coated with the lower die and stripe filling nozzle to form a stripe filling coating on the surface of the current collector.

[0010] Furthermore, in step S2, the electrode slurry is subjected to two-stage filtration before the stripe filling nozzle to filter out large particles or agglomerates in the electrode slurry.

[0011] Furthermore, in step S2, while performing graded filtration, large particles or agglomerates are also broken up using an ultrasonic device.

[0012] Furthermore, the tip of the striped filling needle has a micro-concave structure, the inner diameter of the striped filling needle is no greater than 2mm, and the concave depth of the needle tip is 5~30μm.

[0013] Furthermore, during the process of injecting the electrode slurry into the striped filling nozzle, it is necessary to maintain temperature compensation for the electrode slurry to keep the electrode slurry temperature constant, and keep the slurry viscosity ≤1000mPa·s and the slurry solid content ≤20%.

[0014] The present invention also provides a lithium battery coating system, comprising:

[0015] A coating roller, used for input current collector;

[0016] A coating die head is placed above the coating roller. The coating die head is composed of an upper die head and a lower die head. The coating die head is connected to a coating delivery pipe for inputting electrode slurry.

[0017] A striped filling nozzle is provided with a needle tip. The striped filling nozzle is positioned in front of the coating die head with the needle tip pointing towards the coating roller. The striped filling nozzle is connected to an auxiliary conveying pipe for inputting electrode slurry.

[0018] A striped filler coating primary filter valve and a striped filler coating secondary filter valve are sequentially connected to the auxiliary conveying pipeline. Both the striped filler coating primary filter valve and the striped filler coating secondary filter valve are equipped with filter screens for filtering the electrode slurry.

[0019] Furthermore, both the striped filling coating primary filter valve and the striped filling coating secondary filter valve are equipped with ultrasonic devices.

[0020] Furthermore, a flexible hose is provided between the striped filling nozzle and the auxiliary delivery pipe, and a bending control device is provided at the connection position between the striped filling nozzle and the auxiliary delivery pipe.

[0021] Furthermore, a temperature compensation device is also installed on the auxiliary conveying pipeline.

[0022] The present invention also provides a lithium battery, comprising a linear stripe-filled positive electrode and a linear stripe-filled negative electrode manufactured by the lithium battery coating method according to any one of claims 1-5.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] This invention achieves linear filling coating on the surface of the current collector by setting a striped filling nozzle. In addition to ensuring the effect of the original technical solution, it can also fundamentally improve the performance of lithium-ion batteries through the effect of the coating.

[0025] For example, linearly filled conductive coatings can significantly improve the interface kinetics of lithium-ion batteries;

[0026] Linear filler safety coatings such as alumina and solid electrolytes can not only improve the electrochemical performance of the battery cell, but also reduce the surface current density distribution of the electrode, enhance the surface stability of the electrode, and greatly improve the safety performance of lithium-ion batteries. Attached Figure Description

[0027] To more clearly illustrate the technology in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0028] Figure 1 This is a schematic flowchart of a method for manufacturing an arc-shaped battery according to the present invention;

[0029] Figure 2 This is a schematic diagram of the structure of a coating system according to the present invention;

[0030] Figure 3 yes Figure 2 Enlarged view of region A in the middle;

[0031] Figure 4 This is a schematic diagram of the assembly of the coating die head and the temperature compensation device in this invention;

[0032] Figure 5 This is a schematic diagram of the structure of the striped filling needle of the present invention;

[0033] Figure 6 This is a schematic diagram showing the connection between the striped filling needle, the bending control device and the auxiliary conveying pipe of the present invention.

[0034] Figure 7 This is a schematic diagram of the cross-sectional structure of the linear stripe-filled positive electrode or the linear stripe-filled negative electrode of the present invention.

[0035] The diagram includes:

[0036] 1. Striped filling nozzle; 11. Micro-concave structure; 2. Coating die head; 21. Discharge port; 22. Coating layer; 23. Striped filling coating; 24. Current collector; 25. Upper die head; 26. Lower die head; 3. Coating conveying pipeline; 31. Coating controller; 4. Auxiliary conveying pipeline; 41. Temperature compensation device; 42. Striped filling coating controller; 5. Striped filling coating primary filter valve; 6. Striped filling coating secondary filter valve; 7. Ultrasonic device; 10. Bending control device; 101. Hose; 9. Coating roller. Detailed Implementation

[0037] The technology of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only one embodiment of the present invention, and not all embodiments. 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.

[0038] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0039] Furthermore, if the embodiments of the present invention involve descriptions such as "first" or "second", such descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated.

[0040] like Figures 1 to 7 As shown, the present invention discloses a lithium battery coating method, a coating system, and a lithium battery.

[0041] Example 1

[0042] like Figure 1 As shown, the present invention provides a lithium battery coating method, comprising the following steps:

[0043] S1. Provide electrode slurry and set stripe filling nozzle 1 to form a micro-concave structure 11, and transport the electrode slurry to the coating system so that the electrode slurry enters the coating die head 2 and the stripe filling nozzle 1 respectively.

[0044] Specifically as follows:

[0045] S101. Prepare the electrode slurry in advance. In this step, it is preferable that the same slurry system is used for the electrode slurry input to the coating die head 2 and the stripe filling nozzle 1.

[0046] When the electrode slurry input to the stripe filling nozzle 1 is an oil-based slurry system, the electrode slurry input to the coating die head 2 is also an oil-based slurry system.

[0047] If the electrode slurry input to the stripe filling nozzle 1 is an aqueous slurry system, then the electrode slurry input to the coating die head 2 is also an aqueous system.

[0048] Of course, in some embodiments, the input electrode slurry is a slurry of a different system. In this case, a dispersant that can reduce interfacial tension needs to be added to the two slurry systems. The dispersant needs to take into account both aqueous and oily system environments, and an amphoteric dispersant is preferred.

[0049] The aforementioned amphoteric dispersant can be anionic, amphoteric, electrically neutral, polymeric, or inorganic dispersant.

[0050] Anionic dispersants can be any one or more of sodium oleate C17H33COO-Na, carboxylates, sulfates (RO-SO3Na), sulfonates (R-SO3Na), etc.

[0051] Amphoteric dispersants can be phosphate ester type polymers, etc.

[0052] Electroneutral dispersants can be electronegative amine salts, polycarboxylate salts, etc.

[0053] Inorganic dispersants can be any one or more of sodium pyrophosphate, sodium tripolyphosphate, sodium hexametaphosphate, etc.

[0054] The polymeric dispersant can be any one or more of paraffin wax, sodium polyacrylate, polyvinyl alcohol, polyethylene glycol, etc.

[0055] S102, electrode slurry is fed into coating die head 2 and stripe filling nozzle 1 through coating conveying pipe 3 and auxiliary conveying pipe 4 respectively.

[0056] S2. Perform multi-stage filtration on the electrode slurry entering the striped filling nozzle 1 to control the particle size of the electrode slurry.

[0057] Preferably, the electrode slurry is subjected to two-stage filtration before the striped filling nozzle 1 to filter out large particles or agglomerates in the electrode slurry. Specifically, a striped filling coating primary filter valve 5 and a striped filling coating secondary filter valve 6 are sequentially installed on the auxiliary conveying pipeline 4. Both filter valves are equipped with filter screens to block large particles or agglomerates in the electrode slurry, so as to obtain an electrode slurry with a particle size of D50≦50µm and DMax≦100µm.

[0058] Considering that the accumulation of large particles or agglomerates can easily cause filter clogging, both the primary filter valve 5 and the secondary filter valve 6 of the stripe filling coating in this embodiment are additionally equipped with ultrasonic devices 7. The ultrasonic devices 7 break up large particles or agglomerates and promote the continuous and stable passage of slurry through the filter, reducing the risk of clogging. The operating frequency of the ultrasonic devices 7 is set in the range of 20-40kHz and can be adjusted in real time according to the viscosity and flow rate of the slurry to ensure filtration efficiency and coating continuity. The electrode slurry after two stages of filtration then enters the stripe filling nozzle 1, providing a stable fluid guarantee for subsequent precision stripe coating.

[0059] Preferably, during the electrode slurry transportation process, the temperature may drop, leading to an increase in the viscosity of the electrode slurry, which in turn affects its fluidity and coating uniformity. In this invention, during the electrode slurry input stripe filling nozzle 1, temperature compensation of the electrode slurry is maintained to keep the electrode slurry temperature constant, maintain the slurry viscosity ≤1000mPa·s, and the slurry solid content ≤20%, so that the electrode slurry maintains good fluidity and prevents slurry blockage.

[0060] S3. Adjust the contact height between the stripe filling nozzle 1 and the coating section so that the height of the stripe filling nozzle 1 to the coating section is different from the height of the coating die head 2 to the coating section.

[0061] Specifically: The vertical position of the stripe filling needle 1 is adjusted by the set bending control device 10, and the maximum distance between the needle tip of the stripe filling needle 1 and the coating section is set to L. 1， The distance between the outlet 21 of the coating die 2 and the coating section is L, such that L1 is greater than half of L, thereby ensuring that the maximum depth of the stripe-filling coating 23 in the final coating 22 is less than half the thickness of the coating 22. By precisely controlling the difference between L1 and L, it is ensured that the stripe-filling nozzle 1 forms a locally micro-convex fluid accumulation in the coating section. The stripe structure is self-positioned and formed by the synergistic effect of the slurry surface tension and the substrate movement speed. At the same time, the setting of L1 avoids flow field interference between the nozzle and the die, prevents slurry backflow or thickness fluctuation, and ensures a clear and smooth interface between the main coating 22 and the stripe area, further improving the uniformity of the electrode surface morphology and the consistency of subsequent assembly.

[0062] S4. Simultaneously, the current collector 24 is input into the coating roller 9 to cooperate with the lower die head 26 and the stripe filling nozzle 1 to perform coating operations, so that the stripe filling coating 23 is formed on the surface of the current collector 24.

[0063] The current collector 24 runs at a uniform speed with the coating roller 9, and the tension control system keeps the surface flat and wrinkle-free. The electrode slurry flows out uniformly from the coating die head 2 to form the coating layer 22. At the same time, the stripe filling nozzle 1 is intermittently fed under precise timing control, and a stripe filling coating 23 with a regular stripe structure is simultaneously constructed on the surface of the coating layer 22.

[0064] The number of stripe-filled coatings 23 formed on the coating layer 22 is determined by the number and arrangement of the stripe-filled nozzles 1. Multiple stripe-filled nozzles 1 are evenly distributed along the coating width direction, which can simultaneously realize the continuous formation of multiple stripes and improve coating efficiency. The number of stripe-filled nozzles 1 can be set as needed to match different electrode design requirements. The arrangement spacing of the stripe-filled nozzles 1 is adapted to the stripe width to ensure the consistency of the stripe structure in the coating direction and the transverse direction.

[0065] The needle tip of the striped filling needle 1 of the present invention is a micro-concave structure 11. The inner diameter of the striped filling needle 1 is no greater than 2 mm, and the concave depth of the needle tip is 5-30 μm. The size of the inner diameter of the striped filling needle 1 affects the width of the striped filling coating 23, and the concave depth of the needle tip affects the depth of the striped filling coating 23.

[0066] Preferably, the maximum width Wmax of the stripe filling coating 23 is ≤1mm, and the maximum depth Lmax is less than 50% of the thickness of a single-sided coating.

[0067] Example 2

[0068] like Figures 2 to 7 As shown, this embodiment provides a lithium battery coating system, including: a coating roller 9, a coating die 2 placed above the coating roller 9, a coating conveying pipe 3, an auxiliary conveying pipe 4, a stripe filling needle 1, a stripe filling coating primary filter valve 5, and a stripe filling coating secondary filter valve 6.

[0069] In this invention, the coating roller 9 is used to carry the current collector 24 and drive it to run continuously and stably. The surface is treated with high-precision grinding to ensure consistent linear speed.

[0070] The coating die 2 is positioned above the coating roller 9. Generally, the coating die 2 of the present invention is composed of an upper die 25 and a lower die 26. A stable fluid extrusion channel is formed between the upper die 25 and the lower die 26 to ensure that the electrode slurry is uniformly coated on the surface of the current collector 24 under constant pressure, forming a coating layer 22 of uniform thickness. The exit edge of the lower die 26 is precision polished to reduce the slurry flow resistance and avoid tailing or accumulation defects.

[0071] The present invention connects the coating conveying pipe 3 to the coating die head 2 to input the electrode slurry into the fluid extrusion channel, thereby realizing the input of the electrode slurry. Preferably, in order to accurately control the input of the electrode slurry, a coating controller 31 is provided on the coating conveying pipe 3, preferably a coating pump or a flow regulating valve, to monitor and adjust the slurry conveying rate in real time, so as to ensure the stability of the coating surface density.

[0072] The auxiliary conveying pipe 4 is connected to the stripe filling nozzle 1 and is used to convey the filling slurry for forming the stripe structure. The auxiliary conveying pipe 4 is equipped with a stripe filling coating primary filter valve 5 and a stripe filling coating secondary filter valve 6 to remove small particles or clumps in the filling slurry step by step, prevent nozzle blockage, and ensure the morphology of the stripe filling coating 23 is stable.

[0073] The striped filling nozzle 1 is installed on one side of the lower die head 26, facing the running direction of the current collector 24. The opening and closing sequence is controlled by the striped filling coating controller 42, and the position is precisely matched with the coating speed.

[0074] The stripe filling nozzle 1 is provided with a needle tip. In this embodiment, the needle tip is set as a micro-concave structure 11 with an inner diameter of no more than 2 mm and a concave depth of 5-30 μm. This micro-concave structure 11 helps to form a stable slurry accumulation pattern on the stripe filling coating 23 and improves the integrity and depth consistency of the stripe edges.

[0075] In this embodiment, the position of the striped filling nozzle 1 is adjustable. Specifically, a flexible hose 101 is provided between the striped filling nozzle 1 and the auxiliary delivery pipe 4. A bending control device 10 is provided at the connection position between the striped filling nozzle 1 and the auxiliary delivery pipe 4. The bending angle of the flexible hose 101 is adjusted by the bending control device 10 to achieve precise positioning of the nozzle in three-dimensional space. That is, the bending control device 10 is used to adjust the contact height between the striped filling nozzle 1 and the coating interface (the contact height between the needle tip and the surface of the current collector 24). The bending control device 10 is a common angle adjustment device. For example, the angle of the striped filling nozzle 1 can be adjusted by adjusting the screw, rotating the joint / hinge and locking the structure. The reciprocating extension or oscillation of the needle tip is achieved by the drive mechanism, thereby accurately controlling the forming position and tilt angle of the striped filling coating 23 on the surface of the current collector 24, ensuring the spatial matching accuracy between the striped structure and the main coating coating 22, adapting to the striped filling requirements of different spacings, and further improving the process flexibility.

[0076] Preferably, the distance from the needle tip to the coating interface is greater than half the distance from the coating die 2 to the coating interface, thereby achieving precise control over the depth and width of the final stripe filling coating 23, i.e., the depth of the stripe filling coating 23 is less than 50% of the thickness of the coating 22.

[0077] The striped filling coating primary filter valve 5 and the striped filling coating secondary filter valve 6 are used for filtering the electrode slurry. Both the primary filter valve 5 and the secondary filter valve 6 are equipped with filter screens, achieving two-stage filtration. Of course, multiple filter valves can be set to achieve multi-stage filtration under some special requirements. By filtering the electrode slurry through two filter valves, the particle size of the electrode slurry can be effectively controlled within D50≤50µm and DMax≤100µm, ensuring good flowability of the slurry in the striped filling nozzle 1 and preventing slurry clogging.

[0078] Meanwhile, to prevent clogging of the striped filler coating primary filter valve 5 and the striped filler coating secondary filter valve 6, both the primary filter valve 5 and the secondary filter valve 6 are equipped with an ultrasonic device 7. The ultrasonic device 7 performs ultrasonic crushing of large particles and agglomerates on the filter screen to ensure continuous and stable slurry flow. It can also work with a pressure sensing system to monitor the pressure difference between the two ends of the filter in real time. When the pressure difference exceeds the threshold, the backwashing program is automatically triggered to remove blockages and maintain the flow rate. The ultrasonic frequency is controlled in the range of 20 to 40 kHz, which can effectively deagglomerate without damaging the rheological properties of the slurry.

[0079] Preferably, a temperature compensation device 41 is also installed on the auxiliary conveying pipeline 4. The temperature compensation device 41 heats and insulates the auxiliary conveying pipeline 4 to maintain the temperature stability of the slurry during the conveying process, preventing viscosity fluctuations caused by ambient temperature differences, which would affect the consistency and accuracy of stripe filling. The temperature compensation device 41 is set within a range of 25–45°C, and dynamically adjusts the heating power in conjunction with a real-time feedback control system to ensure that the slurry maintains uniform flow characteristics within the microchannels, further improving the stability and repeatability of the coating quality.

[0080] Can Figure 2 As shown, the temperature compensation device 41 can be installed on the heating base on the upper die head 25, and then the auxiliary conveying pipe 4 is directly connected to the heating base. The heat from the heating base is used to uniformly heat the auxiliary conveying pipe 4, ensuring that the slurry maintains a constant temperature during the conveying process. This design not only avoids the influence of the external environment on the viscosity of the slurry, but also effectively reduces the risk of condensation or solidification on the inner wall of the pipe, further ensuring the continuity and stability of the stripe filling process. The contact part between the heating base and the auxiliary conveying pipe 4 is wrapped with thermally conductive silicone to improve heat conduction efficiency and reduce heat loss, ensuring a uniform temperature field distribution.

[0081] In some embodiments, a temperature sensor may also be provided, which is embedded in the middle section of the auxiliary conveying pipe 4 to monitor the actual temperature of the slurry in real time and feed the data back to the control system to form a closed-loop regulation, avoiding over-overflow or under-temperature phenomena. Combined with the current ambient temperature and humidity and process parameters, the system can automatically optimize the heating curve to adapt to the rheological requirements of different slurry systems. The structure is compact, easy to maintain, and suitable for high-precision stripe filling coating scenarios, significantly improving long-term operational stability and process reproducibility.

[0082] Example 3

[0083] The present invention also provides a lithium battery, including a linear stripe-filled positive electrode and a linear stripe-filled negative electrode prepared by the above-described lithium battery coating method and equipment, and also includes a separator, an electrolyte and a shaped tab.

[0084] Both the linear stripe-filled positive electrode and the linear stripe-filled negative electrode adopt the linear stripe coating technology described above, such as... Figure 7 As shown, a coating 22 and a stripe-filled coating 23 are formed on the outer surface of the current collector 24. The linear stripe-filled negative electrode is a silicon-graphite composite negative electrode material, and both the coating 22 and the stripe-filled coating 23 are conductive coatings, with SP as the main conductive agent. The linear stripe-filled positive electrode is lithium cobalt oxide, and both the coating 22 and the stripe-filled coating 23 are LATP oxide solid electrolytes.

[0085] The conductive SP of the stripe-filled coating 23 in the linear stripe-filled negative electrode can significantly improve the interfacial conductivity of the silicon-doped negative electrode. Furthermore, the more porous structure of the linear conductive filling layer provides stress relief space for the volume expansion of the silicon negative electrode, effectively reducing its volume expansion. The LATP of the linear stripe-filled coating 23 in the linear stripe-filled positive electrode can improve cell safety performance, significantly mitigating overcharging and over-discharging hazards. LATP also improves the cell's low-temperature performance; due to its high ionic conductivity, LATP effectively increases the lithium-ion migration rate at low temperatures, resulting in a significant improvement in low-temperature performance.

[0086] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A lithium battery coating method, characterized in that, Includes the following steps: S1. Provide electrode slurry and set stripe filling nozzle (1) to form a micro-concave structure (11) of stripe filling nozzle (1) to deliver electrode slurry to coating system so that electrode slurry enters coating die head (2) and stripe filling nozzle (1) respectively. S2. Perform multi-stage filtration on the electrode slurry entering the stripe filling nozzle (1) to control the particle size of the electrode slurry. S3. Adjust the contact height between the stripe filling nozzle (1) and the coating section so that the height of the stripe filling nozzle (1) to the coating section is different from the height of the coating die (2) to the coating section. S4. Simultaneously input the current collector (24) into the coating roller (9) and cooperate with the lower die head (26) and stripe filling nozzle (1) to perform coating operation, so that a stripe filling coating (23) is formed on the surface of the current collector (24).

2. The lithium battery coating method according to claim 1, characterized in that, In step S2, the electrode slurry is filtered in two stages before the striped filling nozzle (1) to filter out large particles or agglomerates in the electrode slurry.

3. The lithium battery coating method according to claim 2, characterized in that, In step S2, while performing graded filtration, an ultrasonic device (7) is used to break up large particles or agglomerates, so that the particle size of the electrode slurry is kept between D50≦50µm and DMax≦100µm.

4. The lithium battery coating method according to claim 1, characterized in that, The inner diameter of the striped filling needle (1) is no greater than 2 mm, and the concave depth of the needle tip is 5~30 μm.

5. The lithium battery coating method according to claim 1, characterized in that, During the process of injecting the electrode slurry into the striped filling nozzle (1), it is necessary to maintain the temperature compensation of the electrode slurry to keep the temperature of the electrode slurry constant, and keep the slurry viscosity ≤1000mPa·s and the slurry solid content ≤20%.

6. A lithium battery coating system, characterized in that, include: Coating roller (9), which is used to input current collector (24); A coating die (2) is placed above the coating roller (9). The coating die (2) is composed of an upper die (25) and a lower die (26). The coating die (2) is connected to a coating conveying pipe (3) for inputting electrode slurry. Striped filling nozzle (1), the striped filling nozzle (1) is provided with a needle tip, the striped filling nozzle (1) is placed in front of the coating die head (2) and the needle tip faces the coating roller (9), the striped filling nozzle (1) is connected to an auxiliary conveying pipe (4) for inputting electrode slurry; The striped filling coating primary filter valve (5) and the striped filling coating secondary filter valve (6) are connected in sequence to the auxiliary conveying pipeline (4). Both the striped filling coating primary filter valve (5) and the striped filling coating secondary filter valve (6) are equipped with filter screens for filtering the electrode slurry.

7. A lithium battery coating system according to claim 6, characterized in that, Both the striped filling coating primary filter valve (5) and the striped filling coating secondary filter valve (6) are equipped with ultrasonic devices (7).

8. A lithium battery coating system according to claim 6, characterized in that, A flexible hose (101) is provided between the striped filling nozzle (1) and the auxiliary conveying pipe (4), and a bending control device (10) is provided at the connection position between the striped filling nozzle (1) and the auxiliary conveying pipe (4).

9. A lithium battery coating system according to claim 6, characterized in that, A temperature compensation device (41) is also installed on the auxiliary conveying pipeline (4).

10. A lithium battery, characterized in that, This includes linear stripe-filled positive electrode sheets and linear stripe-filled negative electrode sheets manufactured by the lithium battery coating method according to any one of claims 1-5.

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