Method for manufacturing a current collector-free pole piece, battery

Abstract

The application discloses a preparation method of a current collector-free pole piece, and a battery, and the preparation method comprises the following steps: S100, mixing an electrode active material, a conductive agent, a binder and a solvent to obtain a coating slurry; S200, performing antistatic treatment on a to-be-coated substrate to obtain a coating substrate; S300, coating the coating slurry in the step S100 on the coating substrate in the step S200 and drying to obtain a pole piece with a coating substrate; and S400, performing film tearing treatment on the pole piece with the coating substrate in the step S300 to obtain the current collector-free pole piece. The preparation method is simple and easy to operate, the current collector-free pole piece prepared by the method has good rate performance, high capacity retention rate and good consistency between parallel samples, and is beneficial to the accuracy of the electrochemical performance test of the battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a method for preparing a current collector-free electrode and a battery. Background Technology

[0002] Lithium-ion batteries are widely used in electronic products across various fields due to their long lifespan and high energy density. Currently, traditional current collector coating methods are commonly used to prepare positive and negative electrode sheets for lithium-ion batteries, which are then assembled into coin cells for electrochemical performance testing. This facilitates rapid screening of high-performance materials suitable for lithium-ion batteries. However, because the active material coating quality of coin cell electrodes is relatively small, fluctuations in the current collector quality can easily affect the measurement of active material quality, leading to significant differences in specific capacity between parallel coin cell samples. This makes it difficult to accurately assess the electrochemical performance of the materials. Existing technology discloses a method for fabricating a flexible current collector-free electrode. This method requires multiple steps after coating to obtain the current collector-free electrode, making the operation complex and costly. Moreover, the rate performance and energy density of the current collector-free electrode prepared by this method are not ideal, thus affecting the electrochemical performance of the battery. Summary of the Invention

[0003] This application provides a method for preparing a current collector-free electrode and a battery. The preparation method described in this application is simple and easy to operate, and the current collector-free electrode prepared has good rate performance, high capacity retention, and good consistency between parallel samples, which is beneficial to the accuracy of battery electrochemical performance testing.

[0004] Firstly, this application provides a method for preparing a current collector-free electrode sheet, the method comprising the following steps: S100: mixing electrode active material, conductive agent, binder and solvent to obtain a coating slurry. S200: subjecting the substrate to be coated to antistatic treatment to obtain a coating substrate. S300: coating the coating slurry obtained in step S100 onto the coating substrate obtained in step S200, and drying to obtain an electrode sheet with a coating substrate. S400: subjecting the electrode sheet with a coating substrate obtained in step S300 to a film-removal treatment to obtain the current collector-free electrode sheet. In step S400, after the film-removal treatment, the electrode sheet is further subjected to punching and cold pressing. By subjecting the substrate to be coated to antistatic treatment, this application can significantly reduce scratches on the electrode sheet surface and reduce the cold pressing pressure required in subsequent steps. The reduction in cold pressing pressure can avoid damage to material particles caused by the cold pressing process, thus protecting the integrity of the material particles to a greater extent and improving the cycle life of the battery.

[0005] In some embodiments, in step S200, the triboelectric voltage of the coating substrate is less than 100V. When the electrostatic index meets the above condition, the van der Waals force between the coating substrate and the electrode can be reduced, thereby reducing the scratches left by the coating substrate and the electrode during peeling and improving the consistency of the current collectorless battery.

[0006] For example, the triboelectric voltage of the coating substrate is 0V, 20V, 50V, 60V, 80V, 90V, 95V, 98V, 99V or any two of the above values.

[0007] It should be noted that this application does not impose any special restrictions on the method of antistatic treatment. In principle, it is sufficient to achieve an antistatic index (i.e., triboelectric voltage) of the coated substrate within the aforementioned range.

[0008] For example, an antistatic treatment method may involve placing the substrate to be coated in a plasma device and using proton bombardment technology in a plasma environment, setting the device operating frequency to 13.56MHz to 2.45GHz, and treating the substrate for 1 to 2 hours. Antistatic treatment methods for the substrate include, but are not limited to, plasma device treatment, laser irradiation, and cryogenic treatment. The above are merely illustrative examples; as long as the antistatic index described in this application can be achieved, this application does not limit the actual operating method used.

[0009] In some embodiments, the triboelectric voltage of the coating substrate is less than or equal to 90V. Further reducing electrostatic adsorption forces allows the prepared electrode to have a lower AC impedance after assembly into a coin cell, which is beneficial for improving the electrochemical reaction kinetics of the battery. It also facilitates the peeling of the electrode during the preparation process, significantly reducing tearing force compared to existing technologies, thus avoiding damage to the electrode during peeling and further reducing cold pressing pressure.

[0010] For example, the triboelectric voltage of the coating substrate is 0V, 10V, 30V, 55V, 65V, 75V, 80V, 85V, 90V or any two of the above values.

[0011] In some embodiments, step S300 includes: laying the coating substrate described in step 2 flat on a glass plate so that the coating substrate and the glass plate are completely adhered, wherein complete adhesion means that the coating substrate is adhered to the glass plate without wrinkles or air bubbles. Then, the coating slurry described in step S100 is applied to the surface of the coating substrate facing away from the glass plate.

[0012] In some embodiments, in step S300, the coating slurry is applied to a thickness of 100 μm to 200 μm. Within this range, the antistatic coating substrate functions better, facilitating complete and undamaged adhesive removal.

[0013] For example, the thickness of the coating slurry is 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm, 170μm, 180μm, 190μm, 200μm or any two of the above values.

[0014] In some embodiments, the drying temperature in step S300 is between 85°C and 110°C. If the temperature is too low (below 85°C), the coating substrate cannot maintain its antistatic state for a long time. The antistatic state refers to the state of the coating substrate after antistatic treatment. If the temperature is too high (above 110°C), the electrode may lift at the edges and cannot maintain a long-term adhesion with the coating substrate. The lifted electrode is prone to breakage or cracking during the adhesive removal process, affecting the electrochemical performance of the battery.

[0015] For example, the drying temperature is 85°C, 90°C, 95°C, 100°C, 105°C, 110°C or a range of any two of the above values.

[0016] In some embodiments, the adhesive force between the coating substrate and the glass plate is greater than the tearing force during the film removal process. This helps ensure the integrity of the electrode sheet during the film removal process and avoids unevenness on the electrode sheet surface caused by regional separation of the coating substrate and the glass plate, or by the formation of bubbles and creases.

[0017] In some embodiments, the adhesion force between the coating substrate and the glass plate is 610 N / mm to 710 N / mm, and the tear force during the film removal process is 347 N / mm to 597 N / mm.

[0018] For example, the adhesive force between the coating substrate and the glass plate is 610 N / mm, 620 N / mm, 630 N / mm, 640 N / mm, 650 N / mm, 660 N / mm, 670 N / mm, 680 N / mm, 690 N / mm, 700 N / mm, 710 N / mm or any two of the above values.

[0019] For example, the tearing force during the film-tearing process is 347 N / mm, 350 N / mm, 360 N / mm, 380 N / mm, 400 N / mm, 430 N / mm, 450 N / mm, 480 N / mm, 500 N / mm, 550 N / mm, 580 N / mm, 590 N / mm, 597 N / mm, or any two of the above values.

[0020] In some embodiments, step S400, the film-peeling process includes peeling the electrode sheet along the coating direction. The coating direction refers to the length direction of the coating, and the length direction of the coating substrate is consistent with the coating direction.

[0021] In some embodiments, the coating substrate is selected from at least one of PE substrate, PVC substrate, BOPP substrate, MOPP substrate or PET substrate.

[0022] Secondly, this application provides a battery comprising an electrode sheet, wherein the electrode sheet is a current collector-free electrode sheet prepared by the above-described preparation method.

[0023] The electrode can be a positive electrode made from a positive active material or a negative electrode made from a negative active material. The choice can be made according to the actual situation, and this application does not limit it.

[0024] The beneficial effects of the technical solutions provided in some embodiments of this application include at least the following: by preparing a current collector-free electrode after antistatic pretreatment of the substrate to be coated, this application can greatly reduce scratches on the electrode surface, reduce the required cold pressing pressure, reduce the breakage of material particles caused by the cold pressing process, and protect the integrity of material particles to a greater extent, thereby improving the cycle life of the battery. Moreover, it can avoid the influence of current collector quality errors on the electrode specific capacity test. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application 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 only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 The AC impedance spectra of Embodiment 1 and Comparative Example 1 of this application are shown.

[0027] Figure 2 These are the specific capacity test curves of Example 1 and Comparative Example 1 of this application at different magnification rates;

[0028] Figure 3 The graphs show the capacity retention rate test curves of Example 1 and Comparative Example 1 at different expansion rates. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0030] Current conventional current collector coating methods involve coating a slurry onto aluminum foil, copper foil, or other commonly used metal foils. Because the active material coating mass of coin cell electrodes is relatively small, fluctuations in the current collector mass easily affect the measurement of the active material mass, leading to significant differences in specific capacity between parallel coin cell samples. This makes it difficult to assess the electrochemical performance of the material. To avoid the impact of current collector mass errors on electrode specific capacity testing, this application provides a convenient method for preparing lithium-ion current collector-free electrodes.

[0031] Example

[0032] The steps for conveniently preparing lithium-ion current collector-free electrodes include:

[0033] 1) Weighing: Before use, the electrode active material, binder, and conductive agent are dried in a forced-air drying oven, and the mass of each material is weighed according to the proportion.

[0034] 2) Pretreatment: The substrate to be coated is subjected to antistatic treatment in a plasma device so that the triboelectric voltage of the substrate after treatment is less than 100V;

[0035] 3) Slurry preparation: First, add the solid binder to an appropriate amount of solvent and stir at room temperature on a magnetic stirrer to mix the solid and liquid. Adjust the speed to 600 r / min to 900 r / min and stir for about 15 min to 20 min until the solid is completely dissolved. Adjust the speed to 400 r / min to 600 r / min until the solution is clear and transparent. Let it stand for 10 min to 15 min to remove air bubbles. Add the conductive agent to the above solution and adjust the speed to 700 r / min to 800 r / min and stir for 15 min to 20 min to form a solid-liquid suspension. Let it stand for 10 min to 15 min to remove air bubbles. Add the electrode active material and adjust the speed to 1800 r / min to 2200 r / min and stir for 60 min to 90 min to disperse the electrode active material and form a stable suspension system. Let it stand for 10 min to 15 min to remove air bubbles to obtain the coating slurry.

[0036] 4) Coating: Place the glass plate flat on the coating table, clean the glass plate with lint-free paper soaked in alcohol, cut the coating substrate to the same length and width as the glass plate, wipe the coating substrate flat in one direction with lint-free paper to make the coating substrate adhere to the glass plate without wrinkles or bubbles, adjust the height of the squeegee to 100μm~200μm, place the squeegee at the top of the glass plate, pour the coating slurry in front of the squeegee, hold the left and right ends of the squeegee, and pull it flat at a uniform speed to the other end of the glass plate. After coating, dry the electrode in a forced-air drying oven at 85℃~110℃ for 1h~2h.

[0037] 5) Peeling off the coating: Gently peel off the electrode sheet along the coating direction;

[0038] 6) Stamping: Use a stamping machine to cut 14mm diameter circular electrode sheets. Press the rod quickly during cutting to ensure that the electrode sheet edges are free of burrs;

[0039] 7) Cold pressing: Before cold pressing, clean the rollers of the cold press, adjust the machine parameters, cut a small piece of cold pressing to test the thickness of the electrode, calculate the cold pressing thickness according to the compaction density range, wrap the electrode with aluminum foil for cold pressing, weigh the electrode and then vacuum dry it at 100℃~110℃ for 3h~5h.

[0040] 8) Assemble the button cell: In the glove box, assemble the button cell in the following order: negative electrode cover - nickel mesh or steel sheet - lithium sheet - separator - electrode - positive electrode cover. The lithium sheet should be placed in the center of the nickel mesh or steel sheet. Add electrolyte to the lithium sheet. The separator should completely cover the lithium sheet and the nickel mesh or steel sheet. Add electrolyte to the separator. The electrode should be in the center of the lithium sheet. When sealing the battery, the negative electrode should be on top. The sealing pressure should be controlled below 700 psi.

[0041] Specifically, in step 1), the types and proportions of the electrode active material, binder, and conductive agent are not limited. For example, the positive electrode active material can be one or more of lithium cobalt oxide, lithium iron phosphate, lithium nickel cobalt manganese oxide, and lithium manganese oxide; the negative electrode active material can be one or more of graphite, lithium titanate, or silicon carbide; the binder can be one or more of carboxymethyl cellulose (CMC), polyvinylidene fluoride (PVDF), polyacrylic acid (PAA), or styrene-butadiene rubber (SBR); and the conductive agent can be one or more of SuperP, acetylene black, or carbon nanotubes. The types of the above substances can be any substances known in the industry. The above are merely illustrative examples; this application does not limit the types of substances, and the above materials can be mixed in any proportion known in the industry.

[0042] In step 2), the electrostatic index should meet the requirement that the friction voltage of the coating substrate is less than 100V. When the electrostatic index meets the above condition, it can reduce the van der Waals force between the coating substrate and the electrode, reduce the scratches left by the coating substrate and the electrode during peeling, and improve the consistency of the current collectorless battery. There are no special restrictions on the antistatic treatment method. In principle, it is sufficient to achieve the requirement of the antistatic index of the tape in this scheme. Among them, preferred antistatic treatment methods can be plasma treatment in a plasma environment, laser irradiation, and cryogenic treatment.

[0043] In step 3), there are no specific restrictions on the stirring process; existing technologies can be referenced. The above are merely illustrative examples, and specific choices can be made according to actual circumstances. This application does not impose any limitations.

[0044] In step 5), the tearing force needs to be controlled. The tearing force range is 347 N / mm to 597 N / mm. When the tearing force is greater than this range, the electrode is prone to breakage; when the tearing force is less than this range, the electrode is difficult to tear off. Tweezers are usually used for tearing. The tip of the tweezers should not have any sharp corners, otherwise it will damage the surface of the electrode. This problem can be solved by attaching / covering Teflon to the sharp part of the tweezers.

[0045] In step 6), there is no specific limitation on the size of the electrode sheets cut from the stamping process; they can be any size known in the industry. Specifically, when manufacturing button cells, the size and shape of the cut electrode sheets are usually circular with a diameter of 12mm to 32mm; when manufacturing stacked cells, the size and shape of the cut electrode sheets are usually square with a diameter of 30*40mm.

[0046] In step 7), there are no special restrictions on the cold pressing process, and existing technologies can be referenced. The above are merely illustrative examples, and specific choices can be made according to actual circumstances; this application does not impose any limitations.

[0047] In step 8), there are no special restrictions on the assembly process, and existing technologies can be referenced. The above are merely illustrative examples, and specific choices can be made according to actual circumstances; this application does not impose limitations.

[0048] The materials used in the embodiments and comparative examples in this application can all be purchased commercially.

[0049] Example 1

[0050] (1) Weighing of materials:

[0051] The mass of lithium cobalt oxide (LiCoO2), conductive carbon (Super-P), and polyvinylidene fluoride (PVDF) was weighed according to a mass ratio of 63:26:11, and the total mass of the above materials was 10g.

[0052] (2) Antistatic treatment:

[0053] PE tape (the substrate to be coated) is placed in a plasma device and bombarded with protons in a plasma environment. The device is set to operate at a frequency of 13.56MHz to 2.45GHz. The tape is treated for 1 hour. After antistatic treatment, the tape is removed, and its electrostatic index is tested. The friction voltage of the tape is found to be 97V. The tape with a friction voltage of 97V after antistatic treatment is the coating substrate. Specifically, the PE tape is 3M 810 PE tape.

[0054] The difference between Examples 2-4 and Example 1 lies in the adjustment of the antistatic treatment time in Examples 2-4, resulting in different friction voltages of the tape in Examples 2-4. For example, in Example 2, the antistatic treatment time was shortened from 1 hour to 45 minutes, and the friction voltage of the tape in Example 2 was 104V. Similarly, the antistatic treatment time was adjusted so that the friction voltage in Example 3 was 96V and the friction voltage in Example 4 was 90V.

[0055] The difference between Comparative Example 1 and Example 1 is that the PE tape in Comparative Example 1 is not treated with antistatic agents.

[0056] (3) Pulping: Add the weighed solid polyvinylidene fluoride (PVDF) to an appropriate amount of N-methylpyrrolidone (NMP) solvent, stir on a magnetic stirrer at room temperature to mix the solid and liquid, adjust the speed to 800 r / min, stir for 15 min until the solid is completely dissolved, adjust the speed to 500 r / min until the solution is transparent and clear, let stand for 10 min to remove air bubbles; then add the weighed conductive carbon (SP) to the above solution, adjust the speed to 800 r / min and stir for 15 min, SP forms a solid-liquid suspension, let stand for 10 min to remove air bubbles; finally add the weighed lithium cobalt oxide (LCO), adjust the speed to 2000 r / min and stir for 60 min, LCO disperses to form a stable suspension system, let stand for 10 min to remove air bubbles.

[0057] (4) Coating: Place the glass plate flat on the coating table, clean the glass plate with lint-free paper soaked in alcohol, cut PE tape that is the same length and width as the glass plate, wipe the PE tape flat in one direction with lint-free paper, and make the PE tape adhere to the glass plate without wrinkles or air bubbles. Control the adhesion force between the PE tape and the glass plate to be between 610 N / mm and 710 N / mm. The height of the scraper is 150 μm. Place the scraper on the upper part of the glass plate, pour the paste in front of the scraper, hold the left and right ends of the scraper with both hands, and pull it flat at a uniform speed to the other end of the glass plate. After coating, dry the plate in a 95℃ forced-air drying oven for 1 hour.

[0058] (5) Tearing off the film: Use tweezers to gently tear off the electrode from the head. The tearing force is tested by a tensile testing machine and the range is 347N / 100mm-597N / 100mm. The tweezers are covered with white Teflon to prevent the sharp ends of the tweezers from damaging the electrode.

[0059] Comparative Example 1 showed a tear strength range of 597 N / 100 mm to 697 N / 100 mm as tested by a tensile testing machine.

[0060] (6) Stamping: Use a stamping machine to cut round electrode sheets with a diameter of 14mm. Press the rod quickly during the cutting process to ensure that there are no burrs on the edge of the electrode sheet.

[0061] (7) Cold pressing: Before cold pressing, the rollers of the cold press are cleaned and the machine parameters are adjusted. A small piece is cut and cold-pressed to test the electrode thickness. The cold-pressed thickness is calculated based on the compaction density range. The electrode is wrapped with aluminum foil for cold pressing. The compaction density of the electrode after cold pressing is 3.905 g / cm³. 3 After weighing, the electrodes were vacuum dried at 105℃ for 4 hours.

[0062] (8) Assemble the button cell: In the glove box, assemble the button cell in the following order: negative electrode cover - nickel mesh - lithium sheet - separator - electrode - positive electrode cover. The lithium sheet should be placed in the center of the nickel mesh or steel sheet. Add electrolyte to the lithium sheet. The separator should completely cover the lithium sheet and nickel mesh. Add electrolyte to the separator. The electrode should be in the middle of the lithium sheet. When sealing the battery, the negative electrode should be on top. The sealing pressure should be controlled below 700 psi.

[0063] Referring to Table 1, which shows the specific capacity distribution test data of the coin cell without current collector electrode prepared in Example 1 of this application and the coin cell with conventional current collector coated electrode, it can be clearly seen that the specific capacity variation coefficient (COV = 0.246%) of the coin cell without current collector electrode is less than that of the coin cell with conventional current collector coated electrode (COV = 0.372%). Therefore, the specific capacity of the coin cell without current collector electrode shows better consistency.

[0064] Table 1

[0065]

[0066]

[0067] Figure 1 For the AC impedance spectra of Example 1 and Comparative Example 1 of this application, the electrode obtained after destaticating the tape and assembling it with the button has a smaller AC impedance, which proves its better electrochemical reaction kinetics.

[0068] Figure 2 and Figure 3The figures show the specific capacity and capacity retention curves of Example 1 and Comparative Example 1 at different magnifications. Examples 1-1 to 1-3 are multiple parallel samples of Example 1, all of which are 12t electrode sheets obtained by destaticating with tape and then cold-pressed to assemble coin cells. Comparative Examples 1-1 to 1-4 are multiple parallel samples of Comparative Example 1, all of which are 12t electrode sheets obtained by not destaticating with tape and then cold-pressed to assemble coin cells. At 0.1C, the average specific capacity of the electrode sheets before and after destaticating with tape is similar, and the range and COV are also comparable. When the magnification exceeds 1C, the average specific capacity of the electrode sheets without destaticating with tape decays rapidly, and the consistency between parallel samples deteriorates. The range and COV increase rapidly. The specific capacity and capacity retention of the electrode sheets after destaticating with tape are higher than those of the electrode sheets without destaticating, and the consistency between parallel samples is good.

[0069] Test method:

[0070] (1) Compacted density calculation: ρ=M / V, V=S*(H-L0). Where M is the electrode coating weight / g, and V is the coating material volume / cm³. 3 L0 is the current collector thickness in cm, and S is the electrode area in cm². 2 H represents the electrode thickness in cm.

[0071] After coating, the electrode sheet is cut into circular pieces with a diameter of 14 mm using a cutting machine. The mass of each piece is weighed and recorded as M (g). Next, the electrode sheet is cold-pressed with aluminum foil under a pressure of 8t. After cold pressing, the thickness of the electrode sheet is measured with a micrometer and recorded as L (mm). The compaction density PD of the cathode electrode sheet can then be expressed as: PD = M / (1540.25 * (LR)) * 1000 (g / cm³) 3 ).

[0072] (2) EIS test: The electrochemical impedance spectroscopy (EIS) in the frequency range of 30mHz to 500kHz at 25℃ was tested using a VMP3B electrochemical workstation.

[0073] (3) Capacity retention rate: At 25℃, the battery was charged to 4.3V at constant current of 0.1C, 0.2C, 0.5C, 1C and 1.5C respectively on the Blue Electric test system. After standing for 5 minutes, it was discharged to 3.0V at constant current of 0.1C, 0.2C, 0.5C, 1C and 1.5C respectively. This is the first cycle. The battery was cycled 300 times under the above conditions. The capacity retention rate after 50 cycles was calculated. The capacity retention rate after the cycle was calculated according to the following formula.

[0074] Capacity retention rate after cycling = (discharge capacity of the corresponding cycle / discharge capacity of the first cycle) × 100%.

[0075] (4) Capacity testing at different expansion rates:

[0076] At 25℃, the battery was charged to 4.3V at 0.1C and left to stand for 5 minutes. Then, it was discharged to 3.0V at 0.1C and left to stand for 5 minutes. The discharge rate was adjusted, and discharge tests were conducted at 0.1C, 0.2C, 0.5C, 1C, and 1.5C respectively. The discharge capacity was obtained for each test. The specific capacity of the battery was obtained by calculating (specific capacity = discharge capacity / mass of active material of electrode).

[0077] (5) Triboelectric voltage test: The triboelectric voltage was tested using a SIMCO FMX-003 electrostatic field tester at room temperature.

[0078] Table 2

[0079]

[0080]

[0081] Compared with Comparative Examples 1-1 to 1-4, Examples 1-1 to 1-3 show that antistatic treatment can reduce the AC impedance of coin cells, which is beneficial to improving the electrochemical kinetic performance of the cells. It can also reduce the cold pressing pressure, which is beneficial to protecting the integrity of material particles, thereby improving the cycle life of the cells.

[0082] Compared with Examples 1-1, Examples 2-4 further adjusted the triboelectric voltage after antistatic treatment. In particular, Example 4 had a triboelectric voltage of 90V on the coated substrate. At this time, the battery had better rate performance, higher capacity retention, and relatively lower cold pressing pressure.

[0083] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A method for preparing a current collector-free electrode, characterized in that, The preparation method includes the following steps: S100: The electrode active material, conductive agent, binder and solvent are mixed to obtain the coating slurry; S200: The substrate to be coated is subjected to antistatic treatment to obtain the coating substrate; S300: The coating slurry described in step S100 is coated onto the coating substrate described in step S200 and dried to obtain an electrode sheet with a coating substrate. S400: The electrode sheet with the coated substrate described in step S300 is subjected to a film-peeling process to obtain the current collector-free electrode sheet; In step S200, the triboelectric voltage of the coating substrate is less than 100V.

2. The preparation method according to claim 1, characterized in that, The triboelectric voltage of the coating substrate is ≤90V.

3. The preparation method according to claim 1, characterized in that, Step S300 includes: laying the coating substrate described in step S200 flat on a glass plate so that the coating substrate and the glass plate are completely adhered, and then applying the coating slurry described in step S100 to the surface of the coating substrate facing away from the glass plate.

4. The preparation method according to claim 1, characterized in that, In step S300, the coating slurry is applied to a thickness of 100 μm to 200 μm. The drying temperature is between 85°C and 110°C.

5. The preparation method according to claim 3, characterized in that, The adhesion between the coating substrate and the glass plate is greater than the tearing force during the film removal process.

6. The preparation method according to claim 5, characterized in that, The adhesion force between the coating substrate and the glass plate is 610 N / mm to 710 N / mm; The tearing force during the film-tearing process is 347 N / mm to 597 N / mm.

7. The preparation method according to claim 1, characterized in that, In step S400, the film peeling process includes peeling the electrode sheet along the coating direction.

8. The preparation method according to claim 1, characterized in that, The coating substrate is selected from at least one of PE substrate, PVC substrate, BOPP substrate, MOPP substrate or PET substrate.

9. A battery, characterized in that, The battery includes electrodes; The electrode is a current collector-free electrode prepared by the preparation method described in any one of claims 1 to 8.

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