Positive electrode binder, positive electrode material, positive electrode plate, preparation method of positive electrode plate and battery
By using acrylonitrile polymers and hydrogenated nitrile butadiene as cathode binders in lithium-ion batteries, the problems of poor flexibility and rate performance were solved, and the flexibility and rate performance of the batteries were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- EVE ENERGY CO LTD
- Filing Date
- 2025-12-30
- Publication Date
- 2026-05-15
AI Technical Summary
In existing lithium-ion batteries, non-fluorinated binders such as polyacrylonitrile and polyimide suffer from poor flexibility and rate performance, which affect the battery's kinetic and cycle performance.
Acrylonitrile polymers and hydrogenated nitrile butadiene nitrile are used as positive electrode binders. By adjusting their mass ratio and using thermally cross-linked hydrogenated nitrile butadiene nitrile, a polymer network is formed, which improves the flexibility and adhesion of the electrode sheet and enhances the dispersibility and continuity of the conductive agent.
It improves the flexibility and peeling force of the positive electrode, enhances the rate performance and dynamic performance of the battery, improves the continuity of lithium-ion conduction and conductive network, and improves the overall performance of the battery.
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Abstract
Description
Technical Field
[0001] This application relates to the field of battery technology, specifically to a positive electrode binder, a positive electrode material, a positive electrode sheet, a method for preparing the same, and a battery. Background Technology
[0002] Lithium-ion batteries mainly rely on the movement of lithium ions between the positive and negative electrodes to work. The positive electrode binder is usually polyvinylidene fluoride (PVDF), but PVDF and its raw materials such as 1,1-difluoro-1-chloroethane (R-142b) are not environmentally friendly.
[0003] In related technologies, non-fluorinated binders such as polyacrylonitrile (PAN) and polyimide (PI) are used to replace polyvinylidene fluoride (PVDF). However, PAN and PI are brittle and can weaken the kinetic performance of the battery. Hydrogenated nitrile butadiene rubber (HNBR) can improve the flexibility and peel strength of the positive electrode, but it has a significant impact on the kinetic performance of the battery. For rate-type (power-type) batteries, it can also affect the cycle performance. Summary of the Invention
[0004] This application provides a positive electrode binder, a positive electrode material, a positive electrode sheet, a method for preparing the same, and a battery, aiming to solve the problems of poor flexibility and poor rate performance of non-fluorinated binders.
[0005] This application provides a positive electrode binder comprising an acrylonitrile polymer and hydrogenated butadiene nitrile, wherein the acrylonitrile polymer comprises at least one of acrylonitrile-acrylate copolymer, acrylonitrile-acrylamide copolymer, and acrylonitrile-acrylate-acrylamide copolymer.
[0006] Optionally, in some embodiments of this application, the mass ratio of the acrylonitrile polymer to the hydrogenated butyronitrile is (55-95):(5-45).
[0007] Optionally, in some embodiments of this application, the hydrogenated nitrile butadiene is a thermally crosslinked type of hydrogenated nitrile butadiene, and the positive electrode binder further includes a crosslinking agent.
[0008] Accordingly, this application also provides a positive electrode material, including a positive electrode active material, a conductive agent, and the above-mentioned positive electrode binder.
[0009] Optionally, in some embodiments of this application, the positive electrode active material includes at least one of ternary positive electrode materials and lithium cobalt oxide; and / or The conductive agent includes one or more of conductive carbon black, conductive carbon fiber, conductive graphite, and carbon nanotubes.
[0010] Optionally, in some embodiments of this application, a dispersant is also included, said dispersant comprising at least one of polyvinylpyrrolidone and polyester dispersants.
[0011] Optionally, in some embodiments of this application, the polyester dispersant includes at least one of polyphosphate esters and nitrogen-containing heterocyclic polyesters.
[0012] Optionally, in some embodiments of this application, the mass of the dispersant is 0.05%-0.4% of the mass of the conductive agent; and / or The mass ratio of the positive electrode active material, the conductive agent, and the positive electrode binder is (96-98.6):(0.7-2):(0.7-2).
[0013] Accordingly, this application also provides a positive electrode sheet, including a current collector and a positive active layer disposed on the surface of the current collector, wherein the positive active layer is formed of the aforementioned positive electrode material.
[0014] Accordingly, this application also provides a method for preparing a positive electrode sheet, comprising: The above-mentioned positive electrode material is placed on the surface of the current collector and then pressed to form a positive electrode active layer, thus obtaining a positive electrode sheet.
[0015] Optionally, in some embodiments of this application, the hydrogenated butyronitrile includes thermally crosslinked hydrogenated butyronitrile, and the method further includes: baking the current collector after pressing and providing the positive electrode material, so that the thermally crosslinked hydrogenated butyronitrile undergoes a thermal crosslinking reaction.
[0016] Optionally, in some embodiments of this application, the baking temperature is 100℃-130℃, and the baking time is 0.5h-6h.
[0017] In addition, this application also provides a battery, including the above-mentioned positive electrode sheet, or a positive electrode sheet prepared by the above-mentioned method for preparing the positive electrode sheet.
[0018] This application uses a combination of acrylonitrile polymers and hydrogenated butadiene nitrile as a positive electrode binder, which can improve the flexibility of the positive electrode sheet, thereby making the electrode sheet less prone to cracking and poor conductivity, and thus improving the rate performance of the battery. Detailed Implementation
[0019] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments in this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0020] This application provides a positive electrode binder, a positive electrode material, a positive electrode sheet, a method for preparing the same, and a battery. These are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative and do not impose numerical requirements or establish an order. Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.
[0021] This application provides a positive electrode binder comprising an acrylonitrile polymer and hydrogenated nitrile butadiene (HNBR), wherein the acrylonitrile polymer comprises at least one of acrylonitrile-acrylate copolymer, acrylonitrile-acrylamide copolymer, and acrylonitrile-acrylate-acrylamide copolymer.
[0022] In this application, acrylonitrile polymers are hard and brittle, with an elongation at break generally below 300%, while hydrogenated nitrile butadiene oxide (HNO₃) has high flexibility, with an elongation at break typically greater than 1000%. Combining these two materials reduces the brittleness of acrylonitrile polymers, thereby improving the flexibility of the positive electrode sheet. This prevents cracking and poor conductivity, thus improving the battery's rate performance. Simultaneously, the cyano groups in HNO₃ provide adhesion, enhancing the peel strength of the positive electrode sheet. HNO₃ has good voltage resistance (>4.5V), making it compatible with lithium-ion battery positive electrode systems. The HNO₃ backbone provides steric hindrance, improving the dispersion and stability of the positive electrode material, enhancing the continuity of the conductive network in the positive electrode sheet, and further improving the battery's rate performance.
[0023] It is understandable that the combination of acrylonitrile polymers and hydrogenated butyronitrile can improve the problem of lithium-ion conduction obstruction caused by the excellent film-forming properties of hydrogenated butyronitrile. At the same time, the steric hindrance of hydrogenated butyronitrile can improve the problem of uneven distribution of conductive agents in the cathode material caused by the large number of polar groups in acrylonitrile polymers.
[0024] Understandably, polyacrylonitrile exhibits strong inter-cyano polarity. By introducing acrylates into copolymerization with acrylonitrile, the acrylate units can disrupt the regularity of the acrylonitrile chain segments and the strong intermolecular polarity, thereby improving the flexibility of the flexible polyacrylonitrile and consequently enhancing the flexibility of the positive electrode sheet. The strong hydrogen bonding of the amide groups can improve the wettability and affinity of the binder to the foil (positive electrode current collector aluminum foil), thereby increasing the peel strength of the positive electrode sheet.
[0025] Optionally, in some embodiments of this application, the mass ratio of the acrylonitrile polymer to the hydrogenated butyronitrile is (55-95):(5-45), for example, it can be 55:45, 60:40, 65:35, 70:30, 75:25, 80:20, 85:15, 90:10, 95:5, etc.
[0026] Optionally, in some embodiments of this application, the hydrogenated butyronitrile includes at least one of non-crosslinked hydrogenated butyronitrile and thermally crosslinked hydrogenated butyronitrile.
[0027] Optionally, in some embodiments of this application, the hydrogenated nitrile butadiene is a thermally crosslinked type of hydrogenated nitrile butadiene, and the positive electrode binder further includes a crosslinking agent.
[0028] It is understandable that thermally crosslinked hydrogenated butyronitrile retains some double bonds in the hydrogenated butyronitrile, which can react with the crosslinking agent to achieve crosslinking under high temperature conditions (such as 100℃-130℃), thereby improving the strength of the hydrogenated butyronitrile and reducing its swelling in the electrolyte, thus improving the kinetic performance of the battery.
[0029] This application provides a positive electrode material, including a positive electrode active material, a conductive agent, and the above-mentioned positive electrode binder.
[0030] Optionally, in some embodiments of this application, the positive electrode active material includes at least one of ternary positive electrode materials and lithium cobalt oxide (LCO).
[0031] Understandably, the cathode binder of this application can meet the flexibility and dispersibility requirements of ternary batteries and lithium cobalt oxide batteries.
[0032] As an example, ternary cathode materials include at least one of nickel-cobalt-manganese (NCM) ternary cathode materials and nickel-cobalt-aluminum (NCA) ternary cathode materials.
[0033] Optionally, in some embodiments of this application, the conductive agent includes one or more of conductive carbon black, conductive carbon fiber, conductive graphite, and carbon nanotubes (CNTs).
[0034] Optionally, in some embodiments of this application, a dispersant is also included, said dispersant comprising at least one of polyvinylpyrrolidone (PVP) and polyester dispersants.
[0035] It is understandable that polyvinylpyrrolidone (PVP) and polyester dispersants are amphiphilic (lipophilic and hydrophilic). One end of them can be adsorbed onto the surface of particles (such as conductive agent particles), while the other end is a long molecular chain that can form a physical barrier, thereby generating a steric hindrance effect that improves the dispersibility of conductive agents.
[0036] Optionally, in some embodiments of this application, the polyester dispersant includes at least one of polyphosphate esters and nitrogen-containing heterocyclic polyesters.
[0037] Understandably, polyphosphates and nitrogen-containing heterocyclic polyesters have good pressure resistance and are compatible with lithium battery cathode systems.
[0038] Optionally, in some embodiments of this application, the mass of the dispersant is 0.05%-0.4% of the mass of the conductive agent.
[0039] Optionally, in some embodiments of this application, the mass ratio of the positive electrode active material, the conductive agent, and the positive electrode binder is (96-98.6):(0.7-2):(0.7-2), for example, it can be 96:2:2, 97:1:2, 97:2:1, 97:1.5:1.5, 98:1:1, 98:0.7:1.3, 98:1.3:0.7, 98.6:0.7:0.7, etc.
[0040] Optionally, in some embodiments of this application, the viscosity of the cathode material is 3000 mPa·s-6000 mPa·s, for example, it can be 3000 mPa·s, 3500 mPa·s, 4000 mPa·s, 4500 mPa·s, 5000 mPa·s, 5500 mPa·s, 6000 mPa·s, etc. This can improve the stability and coating leveling properties of the cathode material.
[0041] It is understandable that the cathode material also contains solvent, and the viscosity of the cathode material can be adjusted by adjusting the solvent content.
[0042] This application provides a method for preparing a cathode material, including: A positive electrode material is obtained by mixing a conductive agent, a positive electrode binder, and a positive electrode active material in a solvent. The positive electrode binder is the positive electrode binder described above.
[0043] Optionally, in some embodiments of this application, mixing the conductive agent and the positive electrode binder in a solvent includes: The positive electrode binder is dispersed in a solvent to form a gel, and then a conductive agent and a positive electrode active material are added.
[0044] Understandably, when acrylonitrile polymers are in powder form, they can be first blended with a solvent to form a colloid, and then mixed with hydrogenated nitrile butyrate (HNBR) and a conductive agent to form a stable and uniform positive electrode material. When acrylonitrile polymers are in liquid form, they can be directly mixed with hydrogenated nitrile butyrate (HNBR) and a conductive agent in a solvent.
[0045] This application provides a positive electrode sheet, including a current collector and a positive electrode active layer disposed on the surface of the current collector, wherein the positive electrode active layer is formed of the aforementioned positive electrode material.
[0046] This application provides a method for preparing a positive electrode sheet, comprising: The above-mentioned positive electrode material is placed on the surface of the current collector and then pressed to form a positive electrode active layer, thus obtaining a positive electrode sheet.
[0047] Optionally, in some embodiments of this application, the pressing pressure is 150kN / m-300kN / m, for example, it can be 150kN / m, 180kN / m, 200kN / m, 220kN / m, 250kN / m, 270kN / m, 300kN / m, etc., and the pressing is carried out at room temperature.
[0048] Optionally, in some embodiments of this application, the hydrogenated butyronitrile includes thermally crosslinked hydrogenated butyronitrile, and the method further includes: baking the current collector after pressing and providing the positive electrode material, so that the thermally crosslinked hydrogenated butyronitrile undergoes a thermal crosslinking reaction.
[0049] It is understandable that when the hydrogenated butyronitrile in the positive electrode binder is non-crosslinked hydrogenated butyronitrile, baking is not required.
[0050] Optionally, in some embodiments of this application, the baking temperature is 100℃-130℃, for example, it can be 100℃, 102℃, 105℃, 107℃, 110℃, 112℃, 115℃, 117℃, 120℃, 122℃, 125℃, 127℃, 130℃, etc., and the baking time is 0.5h-6h, for example, it can be 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, etc.
[0051] This application provides a battery including the above-described positive electrode.
[0052] Optionally, in some embodiments of this application, the battery further includes a negative electrode sheet, wherein the active material of the negative electrode sheet is graphite or silicon-doped graphite.
[0053] Example 1 A positive electrode sheet and its preparation method include: Acrylonitrile-acrylate copolymer was blended with N-methylpyrrolidone (NMP) and then mixed with a conductive agent (conductive carbon black and CNT in a mass ratio of 2:1) and thermally crosslinked hydrogenated butyronitrile (TC-HNBR, which includes the crosslinking agent dicumyl peroxide). Next, a ternary active material (lithium nickel cobalt manganese oxide (NCM)) was added, and then N-methylpyrrolidone (NMP) was added to adjust the viscosity to obtain the positive electrode material (wherein, the mass ratio of acrylonitrile-acrylate copolymer to hydrogenated butyronitrile is 95:5, and the mass ratio of binder (acrylonitrile-acrylate copolymer and hydrogenated butyronitrile), conductive agent and positive electrode material is 1.5:1:97.5). The positive electrode material is coated onto the surface of the current collector, then pressed at 200 kN / m, and then baked at 115℃ for 3 hours to obtain the positive electrode sheet.
[0054] Example 2 This embodiment is basically the same as Embodiment 1, except that the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the cathode material in this embodiment is 85:15.
[0055] Example 3 This embodiment is basically the same as Embodiment 1, except that the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the cathode material in this embodiment is 75:25.
[0056] Example 4 This embodiment is basically the same as Embodiment 1, except that the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the cathode material in this embodiment is 65:35.
[0057] Example 5 This embodiment is basically the same as Embodiment 1, except that the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the cathode material in this embodiment is 55:45.
[0058] Example 6 This embodiment is basically the same as Embodiment 1, except that the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the cathode material in this embodiment is 45:55.
[0059] Example 7 This embodiment is basically the same as embodiment 4, except that the acrylonitrile-acrylate copolymer is replaced with acrylonitrile-acrylamide copolymer in this embodiment.
[0060] Example 8 This embodiment is basically the same as embodiment 4, except that the acrylonitrile-acrylate copolymer is replaced with acrylonitrile-acrylate-acrylamide copolymer in this embodiment.
[0061] Example 9 This embodiment is basically the same as embodiment 4, except that the thermally cross-linked hydrogenated nitrile butadiene nitrile (TC-HNBR) is replaced with the non-cross-linked hydrogenated nitrile butadiene nitrile (NC-HNBR) and the baking at 115°C for 3 hours is cancelled.
[0062] Example 10 This embodiment is basically the same as embodiment 4, except that the positive electrode material in this embodiment also includes a dispersant (polyethylene glycol phosphate). The mass ratio of the binder, conductive agent, dispersant and positive electrode material in the positive electrode material in this embodiment is 1.5:0.998:0.002:97.5.
[0063] Example 11 This embodiment is basically the same as Embodiment 10, except that in this embodiment, polyethylene glycol phosphate is replaced with polyvinylpyrrolidone polyethylene glycol phosphate.
[0064] Comparative Example 1 This comparative example is basically the same as Example 1, except that acrylonitrile-acrylate copolymer and hydrogenated butyronitrile are replaced with polyvinylidene fluoride (PVDF).
[0065] Comparative Example 2 This comparative example is basically the same as Example 1, except that hydrogenated butyronitrile is replaced with acrylonitrile-acrylate copolymer in this comparative example.
[0066] Comparative Example 3 This comparative example is basically the same as Example 1, except that the acrylonitrile-acrylate copolymer is replaced with hydrogenated butyronitrile in this comparative example.
[0067] Comparative Example 4 This comparative example is basically the same as Example 1, except that acrylonitrile-acrylate copolymer and hydrogenated butadiene nitrile are replaced with polyacrylonitrile in this comparative example.
[0068] Test example: The positive electrode sheets obtained from the examples and comparative examples were assembled into a battery (model 18650) and their performance was tested. The test results are shown in Table 1.
[0069] Peel strength test procedure: Cut the positive electrode sheet into strips 300mm long and 30mm wide along the coating direction; attach double-sided tape to the stainless steel plate, attach the positive electrode sheet to the double-sided tape, and roll it 3 times with a roller; clamp one end of the stainless steel plate in the lower fixture of the universal tensile testing machine, and clamp the positive electrode sheet in the upper fixture of the universal tensile testing machine at the other end; the test speed is 500mm / min, and the peel strength test angle is 180°.
[0070] To determine the diameter of the steel needle: Fix a 100mm long steel needle to the fixture; cut the positive electrode sheet into a strip 300mm long and 30mm wide along the coating direction; wrap one end of the positive electrode strip around the steel needle 360°, aligning the two ends, and pull the two ends of the electrode sheet back and forth on the steel needle 3 times; remove the positive electrode sheet and observe whether there are cracks on the inner and outer sides of the positive electrode sheet; initially use the largest diameter steel needle (6mm). If there are no cracks, replace the electrode sheet and reduce the diameter of the steel needle by 0.5mm each time, and test again until cracks appear (if a crack appears at 4mm, then the diameter of the steel needle can be 4.5mm).
[0071] Rate Discharge: Clamp the battery under test onto the charge / discharge tester; set the rate discharge test steps, first charge at 0.2C to the upper limit cutoff voltage of the cell (e.g., 4.4V), let it rest for 10 minutes, and then discharge at different currents (0.2C, 0.5C, 1C, 2C, 3C, 4C) to the lower limit cutoff voltage (e.g., 2.7V) (charge at 0.2C to the upper limit cutoff voltage before each discharge). The rate discharge value is the discharge capacity of each discharge divided by the discharge capacity of 0.2C.
[0072] Table 1 Test Results
[0073] As can be seen from Table 1: Compared with Examples 1-6, the battery in Example 6 has the worst rate performance. It can be seen that the rate performance of the battery can be adjusted by adjusting the mass ratio of acrylonitrile-acrylate copolymer and hydrogenated butyronitrile in the positive electrode sheet.
[0074] Compared with Example 9, Example 4 has a greater positive electrode peeling force and better battery rate performance. It can be seen that by using thermally cross-linked hydrogenated nitrile butadiene, the polymer network formed after thermal cross-linking of hydrogenated nitrile butadiene can coat the positive electrode material, thereby making the positive electrode material more densely distributed, reducing swelling, and weakening the obstacle to lithium ion insertion and extraction, which can increase the positive electrode peeling force and battery rate performance.
[0075] Compared with Example 11, Example 4 and Example 10 have similar peeling force and steel needle diameter. The battery in Example 4 has the lowest rate performance. It can be seen that by adding a dispersant to the positive electrode material, the conductive agent can be more evenly dispersed in the positive electrode, thereby improving the rate performance of the battery.
[0076] Compared with Comparative Example 1, Example 4 has a stronger positive electrode peeling force and better battery rate performance. Both can pass through steel needles with the same diameter. It can be seen that by using a fluorine-free binder to replace the fluorine-containing binder polyvinylidene fluoride, this application can ensure the adhesive strength, electrode flexibility and battery rate performance. At the same time, the binder of this application has better environmental protection.
[0077] Compared with Comparative Example 2, Examples 1-11 show that the positive electrode sheet has greater peeling force, can pass through a smaller diameter steel needle, and has better rate performance. It can be seen that by using acrylonitrile polymers and hydrogenated nitrile butadiene as positive electrode binders, the adhesion of the binder, the flexibility of the electrode sheet, and the rate performance of the battery can be improved.
[0078] Compared with Comparative Example 3, the batteries in Examples 1-11 have better rate performance. It can be seen that by using acrylonitrile polymers and hydrogenated butyronitrile as positive electrode binders, the rate performance of the battery can be improved.
[0079] Compared with Comparative Example 4, the positive electrode of Comparative Example 2 has a smaller diameter of steel needle and better rate performance of the battery. It can be seen that by using acrylonitrile-acrylate copolymer as a binder, the flexibility of the electrode and the rate performance of the battery can be improved compared with polyacrylonitrile.
[0080] The foregoing has provided a detailed description of a positive electrode binder, positive electrode material, positive electrode sheet, its preparation method, and battery provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.
Claims
1. A positive electrode binder, characterized in that, It includes acrylonitrile polymers and hydrogenated butadiene nitrile, wherein the acrylonitrile polymers include at least one of acrylonitrile-acrylate copolymers, acrylonitrile-acrylamide copolymers, and acrylonitrile-acrylate-acrylamide copolymers.
2. The positive electrode binder according to claim 1, characterized in that, The mass ratio of the acrylonitrile polymer to the hydrogenated butyronitrile is (55-95):(5-45).
3. The positive electrode binder according to claim 1, characterized in that, The hydrogenated butyronitrile is a thermally crosslinked type of hydrogenated butyronitrile, and the positive electrode binder also includes a crosslinking agent.
4. A positive electrode material, characterized in that, It includes a positive electrode active material, a conductive agent, and a positive electrode binder as described in any one of claims 1-3.
5. The positive electrode material according to claim 4, characterized in that, The positive electrode active material includes at least one of ternary positive electrode materials and lithium cobalt oxide; and / or The conductive agent includes one or more of conductive carbon black, conductive carbon fiber, conductive graphite, and carbon nanotubes.
6. The cathode material according to claim 4, characterized in that, It also includes a dispersant, which includes at least one of polyvinylpyrrolidone and polyester dispersants.
7. The cathode material according to claim 6, characterized in that, The polyester dispersant includes at least one of polyphosphate esters and nitrogen-containing heterocyclic polyesters.
8. The positive electrode material according to claim 6, characterized in that, The mass of the dispersant is 0.05%-0.4% of the mass of the conductive agent; and / or The mass ratio of the positive electrode active material, the conductive agent, and the positive electrode binder is (96-98.6):(0.7-2):(0.7-2).
9. A positive electrode sheet, characterized in that, It includes a current collector and a positive electrode active layer disposed on the surface of the current collector, the positive electrode active layer being formed of the positive electrode material according to any one of claims 4-8.
10. A method for preparing a positive electrode sheet, characterized in that, include: The positive electrode material according to any one of claims 4-8 is disposed on the surface of the current collector and then pressed to form a positive electrode active layer, thereby obtaining a positive electrode sheet.
11. The method for preparing the positive electrode sheet according to claim 10, characterized in that, The hydrogenated butyronitrile includes thermally cross-linked hydrogenated butyronitrile, and the method further includes: baking the current collector after pressing and providing the positive electrode material, so that the thermally cross-linked hydrogenated butyronitrile undergoes a thermal cross-linking reaction.
12. The method for preparing the positive electrode sheet according to claim 11, characterized in that, The baking temperature is 100℃-130℃, and the baking time is 0.5h-6h.
13. A battery, characterized in that, This includes the positive electrode sheet as described in claim 9, or the positive electrode sheet prepared by the method described in any one of claims 10-12.