Preparation method of ternary precursor, ternary positive electrode material and preparation method of ternary positive electrode material

Abstract

The invention provides a preparation method of a ternary precursor, a ternary positive electrode material and a preparation method of the ternary positive electrode material, and the preparation method of the ternary precursor comprises the following steps: uniformly mixing a ternary metal salt solution and a chelating agent, carrying out spray pyrolysis on the obtained mixed solution, and sequentially passing through three temperature zones from top to bottom to obtain the ternary precursor. According to the preparation method disclosed by the invention, the chelating agent is added into the ternary metal salt solution as an additive, and spray pyrolysis sequentially passes through three temperature zones from top to bottom, so that the problem of hollowing or crushing of secondary particles is solved; the preparation of the solid spheroidic secondary particle precursor with narrow particle size distribution by a ternary metal salt system spray pyrolysis method can be realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion batteries, in particular to a preparation method of ternary precursor, a ternary positive electrode material and a preparation method thereof. BACKGROUND

[0002] Compared with the ternary material precursor prepared by the liquid phase precipitation method, the spray pyrolysis method has the advantages of short preparation time, large yield, low cost, no pollution, adjustable particle size, narrow particle size distribution, easy doping and easy control of element distribution uniformity, and is a lithium ion battery precursor preparation technology with great development potential and application prospect.

[0003] However, the difference in the morphology of the ternary precursor obtained by using ultrasonic spray pyrolysis method on the raw material system of Ni, Co, Mn acetate, nitrate and chloride salt will be found: the solubility of acetate in water is low, the melting point of nitrate is low, and the outer edge of the atomized droplets in the spray drying process of the two solutions is easy to form crust, causing the secondary precursor particles to be broken or hollow, and thus the ternary material prepared by high temperature calcination of the precursor has the problems of low tap density and high specific surface area, which will adversely affect the energy density, cycle stability and safety of the battery; for the chloride salt system, the chloride ion can act as a nucleating agent, which is more conducive to obtaining solid secondary particle precursor, and the chloride salt has an advantage in price compared with the other two types of salt, the corrosion problem of hydrochloric acid can be avoided by using special cobalt alloy steel or zirconia ceramic or plastic material, and the waste gas of hydrochloric acid can be completely recovered, so the chloride salt system is most suitable for industrial production, but the decomposition temperature of chloride salt is high, and it is difficult to decompose completely in the spray pyrolysis tower in a short time, and there is still a problem of hollow or broken secondary particles.

[0004] To solve the problem of hollow or broken secondary particles in the preparation process of ternary precursor and improve the yield, a new preparation method of ternary precursor is needed. SUMMARY

[0005] In view of the problems in the prior art, the present application provides a preparation method of ternary precursor, a ternary positive electrode material and a preparation method thereof, the preparation method of ternary precursor comprises the following steps: uniformly mixing a ternary metal salt solution with a chelating agent to obtain a mixed solution, and then performing spray pyrolysis on the mixed solution, and the spray pyrolysis passes through three temperature zones from top to bottom in sequence to obtain a ternary precursor. The preparation method disclosed in the present application uses the method of adding additives, and sets the spray pyrolysis to pass through three temperature zones from top to bottom in sequence, so as to solve the problem of hollow or broken secondary particles.

[0006] To achieve this purpose, the technical scheme adopted by the present application is as follows:

[0007] One of the purposes of the present application is to provide a preparation method of ternary precursor, which comprises the following steps:

[0008] Mixing the ternary metal salt solution with the chelating agent uniformly to obtain a mixed solution;

[0009] Spray pyrolysis is performed on the mixed solution, which sequentially passes through three temperature zones from top to bottom to obtain the ternary precursor.

[0010] The preparation method of the present application solves the problems of hollowing or breaking of secondary particles by adding the chelating agent as an additive in the ternary metal salt solution and setting the spray pyrolysis to sequentially pass through three temperature zones from top to bottom, which can realize the preparation of solid spherical secondary particle precursor with narrow particle size distribution by spray pyrolysis of ternary metal salt system.

[0011] As a preferred technical solution of the present application, the ternary metal salt solution comprises chloride or nitrate of nickel, cobalt and manganese, and the molar ratio of Ni:Co:Mn is x:y:z; wherein 0.7≤x≤0.9, 0≤y≤0.2, and x+y+z=1.

[0012] It should be noted that the preparation method of the present application preferably uses chloride salt as the metal salt form of ternary precursor, which can realize the purpose of preparing solid spherical secondary particle precursor with narrow particle size distribution by spray pyrolysis of chloride salt system and improve the yield, solves the problems of hollowing and breaking of secondary particles prepared by spray pyrolysis, and creates favorable conditions for preparing ternary material precursor with high tap density, small specific surface area and low chloride content.

[0013] Preferably, the total concentration of metal salt in the ternary metal salt solution is 300-400 g / L, for example 300 g / L, 310 g / L, 330 g / L, 350 g / L, 370 g / L or 400 g / L, etc.

[0014] It should be noted that the preparation process of the ternary metal salt of the present application comprises: first mixing the metal salt with deionized water in a mixer, stirring at 70-100℃ for 4-6 hours to achieve uniform mixing.

[0015] Preferably, the chelating agent comprises at least one of citric acid, formic acid or amino acid.

[0016] Preferably, the addition amount of the chelating agent is 1.0-2.0wt% compared with the ternary metal salt solution, for example 1.0wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt% or 2.0wt%, etc.

[0017] As a preferred technical solution of the present invention, in the spray pyrolysis, the spraying rate of the mixed solution is 10~15L / h, for example 10L / h, 11L / h, 12L / h, 13L / h, 14L / h or 15L / h.

[0018] Preferably, the mixed solution is sprayed from top to bottom through a dual-fluid atomizer nozzle.

[0019] Preferably, the spray angle of the dual-fluid atomizer nozzle is 15 to 30 degrees, such as 15 degrees, 16 degrees, 18 degrees, 20 degrees, 23 degrees, 25 degrees, 27 degrees or 30 degrees.

[0020] Preferably, the spray pyrolysis is carried out in a spray pyrolysis furnace, and a vibrator is installed outside the furnace body. During the spray pyrolysis process, the vibrator causes droplets on the inner wall of the furnace to fall off and participate in the spray pyrolysis by vibrating, thereby reducing the furnace wall material and improving the yield.

[0021] As a preferred technical solution of the present invention, the mixed solution is subjected to spray pyrolysis in sequence through a first temperature zone, a second temperature zone and a third temperature zone, wherein the first temperature zone and the second temperature zone are electrically heated temperature zones, and the third temperature zone is a flame spray zone.

[0022] Preferably, the vertical height of the temperature zone is 16~22m, such as 16m, 17m, 18m, 19m, 20m, 21m or 22m.

[0023] Preferably, the vertical height of the two temperature zones is 10~14m, such as 10m, 10.5m, 11m, 11.5m, 12m, 12.5m, 13m, 13.4m or 14m.

[0024] Preferably, the vertical height of the three temperature zones is 2~6m, such as 2m, 2.5m, 3m, 3.5m, 4m, 4.5m, 5m, 5.5m, or 6m. Preferably, the temperature of the first temperature zone is 100~300℃, such as 100℃, 150℃, 200℃, 250℃, or 300℃.

[0025] Preferably, the temperature of the two temperature zones is 400~500℃, such as 400℃, 410℃, 430℃, 450℃, 460℃, 480℃ or 500℃.

[0026] Preferably, the temperature of the three temperature zones is 600~1000℃, such as 600℃, 700℃, 800℃, 900℃ or 1000℃.

[0027] As a preferred technical solution of the present invention, the ternary precursor is collected under negative pressure during the spray pyrolysis.

[0028] Preferably, the negative pressure pressure of the negative pressure collection is -100~ -300 kPa, for example -100 kPa, -120 kPa, -150 kPa, -170 kPa, -200 kPa, -230 kPa, -250 kPa, -280 kPa or -300 kPa, etc. The negative pressure pressure of the negative pressure collection is controlled, which can not only pump the material to the downstream process, but also pump the waste gas generated by pyrolysis into the environmental protection tower.

[0029] Preferably, after the spray pyrolysis, the ternary precursor is sequentially subjected to washing, drying, airflow breaking and screening to obtain the target ternary precursor oxide.

[0030] It should be noted that the collected oxide precursor is washed, including water washing, which can wash away the chloride ions therein.

[0031] It should be noted that the preparation method of the present application has equipment modification for the spray pyrolysis furnace. In addition to the vibrator arranged outside the furnace body of the spray pyrolysis furnace, the liquid droplets falling on the furnace wall are vibrated to participate in the reaction during the spray pyrolysis process, so as to improve the yield. It also includes: increasing the height of the pyrolysis furnace (the vertical height of the first temperature zone is 16~22 m, the vertical height of the second temperature zone is 10~14 m, and the vertical height of the third temperature zone is 2~6 m), so that the liquid droplets can have enough distance to react; customizing the double-fluid atomizer nozzle to make the sprayed liquid droplets uniform and have a small included angle (the spraying included angle is 15~30 degrees); adding a negative pressure collection system to collect the material in time after the reaction is completed (the negative pressure pressure is -100~ -300 kPa).

[0032] The preparation method of the present application is based on spray pyrolysis. On the one hand, a vibrator is arranged outside the furnace body of the spray pyrolysis furnace, so that the liquid droplets on the inner wall of the furnace body fall off and participate in the spray pyrolysis, reducing the furnace wall material and improving the yield. On the other hand, by adding a chelating agent to the ternary metal salt solution, customizing the double-fluid nozzle, and increasing the height of the pyrolysis furnace, the liquid droplets can have enough distance to react, solving the problem of secondary particle hollowing or breaking.

[0033] The second object of the present application is to provide a preparation method of a ternary positive electrode material. The ternary precursor prepared by the preparation method of the first object is mixed uniformly with a lithium source, and a ternary positive electrode material is prepared by a high-temperature solid phase method.

[0034] As a preferred technical solution of the present application, the ternary positive electrode material and the metal oxide are fully mixed and uniform in the ball mill, and a metal oxide coated ternary positive electrode material is obtained by high-temperature heat treatment.

[0035] As a preferred technical solution of the present application, the high-temperature solid phase method is carried out in a flowing air atmosphere.

[0036] Preferably, the sintering temperature of the high-temperature solid-phase method is 900-1200℃, such as 900℃, 950℃, 1000℃, 1050℃, 1100℃, 1150℃ or 1200℃, etc.

[0037] Preferably, the sintering time of the high-temperature solid-phase method is 18-24h, such as 18h, 19h, 20h, 21h, 22h, 23h or 24h, etc.

[0038] Preferably, the temperature of the high-temperature heat treatment is 1000-1300℃, such as 1000℃, 1050℃, 1100℃, 1150℃, 1200℃, 1250℃ or 1300℃, etc.

[0039] Preferably, the time of the high-temperature heat treatment is 8-20h, such as 8h, 10h, 12h, 14h, 16h, 18h or 20h, etc.

[0040] Preferably, the high-temperature heat treatment is carried out in a roller kiln and under an air atmosphere.

[0041] The third object of the present application is to provide a ternary positive electrode material prepared by the preparation method of the second object.

[0042] Compared with the prior art, the present application has at least the following beneficial effects:

[0043] (1) The preparation method of the present application solves the problem of secondary particle hollowing or breaking by adding a chelating agent as an additive in the ternary metal salt solution and setting the spray pyrolysis to pass through three temperature zones in turn from top to bottom, so that the spray pyrolysis method of the ternary metal salt system can be used to prepare solid spherical secondary particles with narrow particle size distribution.

[0044] (2) The vibrator is arranged outside the furnace body of the spray pyrolysis furnace, so that the liquid drops on the inner wall of the furnace body are caused to drop and participate in the spray pyrolysis, reducing the wall material and improving the yield. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 is a schematic diagram of the furnace body structure of the spray pyrolysis furnace in the embodiment of the present application.

[0046] Figure 2 is a SEM image of the ternary precursor oxide obtained in Example 1 of the present application. DETAILED DESCRIPTION

[0047] The technical solutions of the present application will be further described below by means of specific embodiments and in conjunction with the accompanying drawings.

[0048] In order to better illustrate the present application, facilitate understanding of the technical solutions of the present application, the typical but non-limiting embodiments of the present application are as follows:

[0049] In the specific embodiments of the present application, the spray pyrolysis furnace structure is the same, the inside of the furnace body is divided into a temperature zone, a second temperature zone and a third temperature zone from top to bottom, and two vibrators are arranged on the outside of the furnace body corresponding to each temperature zone, that is, a total of six vibrators are arranged on the outside of the furnace body, so that the furnace body can continuously vibrate during the spray pyrolysis process, and the corresponding structural schematic diagram is shown in Figure 1 .

[0050] Example 1

[0051] The present embodiment provides a preparation method of a ternary precursor, which comprises the following steps:

[0052] The spray pyrolysis furnace is modified: a vibrator is arranged on the outside of the pyrolysis furnace body, and the furnace body continuously vibrates during the pyrolysis process, so that the liquid droplets falling on the furnace wall can vibrate to participate in the reaction, thereby improving the yield; the height of the pyrolysis furnace is increased, the vertical height of the first temperature zone is 18 m, the vertical height of the second temperature zone is 12 m, and the vertical height of the third temperature zone is 4 m, so that the liquid droplets can have enough distance to react; a double-fluid atomizer nozzle is customized, so that the sprayed liquid droplets are uniform and the spray angle is 20 degrees; and a negative pressure collection system is added, so that the materials can be collected in time after the reaction is completed;

[0053] The ternary precursor (oxide) prepared by the spray pyrolysis method:

[0054] (1) Preparation of metal salt solution: 300 g / L of chloride salt solution is prepared according to the molar ratio of Ni:Co:Mn=8:1:1, and the metal salt is mixed with deionized water in a mixer, stirred at 80°C for 4 hours, and uniformly mixed;

[0055] (2) Compared with the ternary metal salt solution, 1.5wt% of citric acid is added and stirred uniformly to obtain a mixed solution;

[0056] (3) The mixed solution is sprayed out from top to bottom through the double-fluid atomizer nozzle at a speed of 15 L / h by means of a metering pump, and sequentially passes through three temperature zones for spray pyrolysis, the temperature of the first temperature zone is controlled at 200°C, the temperature of the second temperature zone is controlled at 400°C, and the temperature of the third temperature zone is controlled at 700°C, and during the spray pyrolysis, the oxide precursor after pyrolysis is collected under negative pressure, the negative pressure is-200 kPa, and a vibrator is added on the outside of the furnace body, so that the furnace body continuously vibrates during the pyrolysis process, the liquid droplets falling on the furnace wall vibrate to participate in the reaction, and the yield is improved;

[0057] (4) The collected oxide precursor is washed with pure water to remove the chloride ions therein, and then subjected to drying, airflow breaking, and sieving to obtain the target ternary precursor oxide.

[0058] The SEM image of the ternary precursor oxide obtained in this example is shown in FIG. 2. Figure 2 As shown in FIG. 2, the ternary precursor oxide obtained in this example has a solid spherical structure and is not damaged.

[0059] Example 2

[0060] This example provides a preparation method of a ternary precursor, wherein the vertical height of one temperature zone is set to 12 m, and the rest of the conditions are the same as those in Example 1.

[0061] Example 3

[0062] This example provides a preparation method of a ternary precursor, wherein the vertical height of one temperature zone is set to 25 m, and the rest of the conditions are the same as those in Example 1.

[0063] Example 4

[0064] This example provides a preparation method of a ternary precursor, wherein the vertical height of two temperature zones is set to 8 m, and the rest of the conditions are the same as those in Example 1.

[0065] Example 5

[0066] This example provides a preparation method of a ternary precursor, wherein the vertical height of two temperature zones is set to 16 m, and the rest of the conditions are the same as those in Example 1.

[0067] Application Example 1

[0068] This application example provides a preparation method of a ternary positive electrode material, which comprises the following contents.

[0069] Preparation of a ternary positive electrode material by a high-temperature solid-phase method: the target ternary precursor oxide prepared in Example 1 is mixed with lithium carbonate at a mass ratio of 1:0.4, and then sintered at 1000℃ for 20 h in a flowing air atmosphere, and naturally cooled to room temperature to prepare a ternary positive electrode material.

[0070] Preparation of a ternary positive electrode material coated with an inert material metal oxide: the ternary positive electrode material and ground Al2O3 are mixed uniformly in a ball mill, and then placed in a roller hearth kiln and subjected to high-temperature heat treatment at 1100℃ in an air atmosphere for 20 h to obtain a ternary positive electrode material coated with a metal oxide.

[0071] Application Example 2

[0072] The application example provides a preparation method of a ternary positive electrode material. Compared with the application example 1, the target ternary precursor oxide prepared by the example 2 is used, and the rest of the conditions are completely same as the application example 1.

[0073] Application Example 3

[0074] The application example provides a preparation method of a ternary positive electrode material. Compared with the application example 1, the target ternary precursor oxide prepared by the example 3 is used, and the rest of the conditions are completely same as the application example 1.

[0075] Application Example 4

[0076] The application example provides a preparation method of a ternary positive electrode material. Compared with the application example 1, the target ternary precursor oxide prepared by the example 4 is used, and the rest of the conditions are completely same as the application example 1.

[0077] Application Example 5

[0078] The application example provides a preparation method of a ternary positive electrode material. Compared with the application example 1, the target ternary precursor oxide prepared by the example 5 is used, and the rest of the conditions are completely same as the application example 1.

[0079] Application Example 6

[0080] The application example provides a preparation method of a ternary positive electrode material. Compared with the application example 1, the inert material metal oxide is not used for coating, and the rest of the conditions are completely same as the application example 1.

[0081] The ternary positive electrode material obtained in the above application example is prepared into a lithium ion battery, and the initial specific capacity, cycle performance and capacity retention rate are tested.

[0082] The ternary positive electrode material, the binder polyvinylidene fluoride and the conductive agent Super P are added into N-methyl pyrrolidone in a mass ratio of 97:1.5:1.5 to stir into a first positive electrode slurry; then the first positive electrode slurry is uniformly coated on the positive electrode current collector aluminum foil, and after drying and rolling, a positive electrode sheet is obtained; graphite, the conductive agent acetylene black, the thickening agent CMC and the binder SBR are mixed in a mass ratio of 96:1:1.5:1.5, and a solvent deionized water is added to fully stir to obtain a negative electrode slurry; the negative electrode slurry is uniformly coated on the negative electrode current collector copper foil, and after drying, cold pressing and slitting, a negative electrode sheet is obtained; ethylene carbonate EC, methyl ethyl carbonate EMC and diethyl carbonate DEC are mixed in a volume ratio of 1:1:1, and then the fully dried lithium salt LiPF6 is dissolved in the mixed solvent to prepare an electrolyte with a concentration of 1 mol / L; the positive electrode sheet, the separator and the negative electrode sheet are sequentially laminated, and then wrapped with an aluminum plastic film, and after drying, the electrolyte is injected, and after packaging, standing and formation, a lithium ion battery is obtained;

[0083] The initial specific capacity is tested under the following conditions: the battery is charged at a rate of 0.2C, and the charging is stopped at a set cut-off voltage of 4.2V, and then the charging is converted to constant voltage charging, which lasts for 8 minutes, and then the battery is left for 2 minutes. The battery is discharged at the same rate of 0.2C, and the discharging is stopped at a set cut-off voltage of 3.0V, and then the battery is left for 2 minutes. According to the current and discharging time recorded during the discharging process, the discharging capacity (mAh) is calculated. According to the mass of the positive electrode material, the specific capacity is calculated; the cycle performance of the battery is tested under 1C / 1C for 100 cycles; the test conditions of the capacity retention rate are as follows: under room temperature conditions, the battery is standard charged and discharged for 3 times to obtain the standard capacity C1 of the battery. The battery is standard charged, and after the charging is completed, the battery needs to be stored at a specific room temperature for 28 days. After the storage period is over, the battery is discharged at a standard discharge rate to obtain the discharging capacity C2. The capacity retention rate is calculated as follows: capacity retention rate = C2 / C1, wherein C1 is the standard capacity of the battery, and C2 is the discharging capacity after storage and discharging. The results are shown in Table 1.

[0084] Table 1

[0085]

[0086] In summary, the preparation method of the application solves the problems of secondary particle hollowing or breaking by adding a chelating agent as an additive in the ternary metal salt solution and setting the spray pyrolysis to pass through three temperature zones from top to bottom, so that the solid spherical secondary particle precursor with narrow particle size distribution can be prepared by the spray pyrolysis method of the ternary metal salt system; the vibrator is arranged outside the furnace body of the spray pyrolysis furnace, the liquid drops on the inner wall of the furnace body are caused to drop off and participate in the spray pyrolysis by vibration, the wall material is reduced, and the yield is improved.

[0087] The application is described above by the above-mentioned embodiments to illustrate the detailed structural features of the application, but the application is not limited to the above-mentioned detailed structural features, i.e. it does not mean that the application must rely on the above-mentioned detailed structural features to be implemented. It should be understood by those skilled in the art that any improvement of the application, equivalent replacement of the components selected by the application, addition of auxiliary components, selection of specific modes, etc. all fall within the protection scope and disclosure scope of the application.

[0088] The preferred embodiments of the application are described in detail above, but the application is not limited to the specific details in the above-mentioned embodiments, and within the technical concept scope of the application, various simple modifications can be made to the technical solutions of the application, and these simple modifications all belong to the protection scope of the application.

[0089] In addition, it should be noted that each specific technical feature described in the above-mentioned specific embodiments can be combined by any suitable method without contradiction, and in order to avoid unnecessary repetition, the application will not further describe various possible combination methods.

[0090] In addition, various different embodiments of the application can also be combined in any way, as long as it does not deviate from the idea of the application, and it should also be considered as disclosed by the application.

Claims

1. A method for preparing a ternary precursor, characterized in that, The preparation method comprises the following steps: mixing the ternary metal salt solution with a chelating agent uniformly to obtain a mixed solution; performing spray pyrolysis on the mixed solution, which sequentially passes through three temperature zones from top to bottom to obtain a ternary precursor.

2. The production method according to claim 1, characterized by, The ternary metal salt solution comprises chloride or nitrate of nickel, cobalt and manganese, and the molar ratio of Ni:Co:Mn is x:y:z; wherein 0.7≤x≤0.9, 0≤y≤0.2, and x+y+z=1. Preferably, the total concentration of metal salt in the ternary metal salt solution is 300-400 g / L. Preferably, the chelating agent comprises at least one of citric acid, formic acid or amino acid. Preferably, the amount of the chelating agent added is 1.0-2.0 wt% compared with the ternary metal salt solution.

3. The production method according to claim 1 or 2, characterized by, In the spray pyrolysis, the spray speed of the mixed solution is 10-15 L / h. Preferably, the mixed solution is sprayed from top to bottom through a double-fluid atomizer nozzle. Preferably, the spray angle of the double-fluid atomizer nozzle is 15-30 degrees. Preferably, the spray pyrolysis is performed in a spray pyrolysis furnace, and a vibrator is arranged outside the furnace body of the spray pyrolysis furnace.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The mixed solution sequentially passes through a one-temperature-zone, a two-temperature-zone and a three-temperature-zone for the spray pyrolysis, wherein the one-temperature-zone and the two-temperature-zone are electric heating temperature zones, and the three-temperature-zone is a flame spraying zone. Preferably, the vertical height of the one-temperature-zone is 16-22 m. Preferably, the vertical height of the two-temperature-zone is 10-14 m. Preferably, the vertical height of the three-temperature-zone is 2-6 m. Preferably, the temperature of the one-temperature-zone is 100-300℃. Preferably, the temperature of the two-temperature-zone is 400-500℃. Preferably, the temperature of the three-temperature-zone is 600-1000℃.

5. The method of any one of claims 1 to 4, wherein the method further comprises the step of: During the spray pyrolysis, the ternary precursor is collected under negative pressure. Preferably, the negative pressure of the negative pressure collection is -100 to -300 kPa. Preferably, after the spray pyrolysis, the ternary precursor is sequentially washed, dried, airflow broken and sieved to obtain a target ternary precursor oxide.

6. A method for preparing a ternary cathode material, characterized in that, The ternary precursor prepared by the preparation method of any one of claims 1-5 is mixed with a lithium source uniformly, and a ternary positive electrode material is prepared by a high-temperature solid-phase method.

7. The production method according to claim 6, characterized by, The ternary positive electrode material is mixed with a metal oxide uniformly, and a metal oxide-coated ternary positive electrode material is obtained by high-temperature heat treatment.

8. The production method according to claim 6 or 7, characterized by, The high-temperature solid-phase method is performed under a flowing air atmosphere. Preferably, the sintering temperature of the high-temperature solid-phase method is 900-1200℃. Preferably, the sintering time of the high-temperature solid-phase method is 18-24 h.

9. The preparation method according to claim 7, characterized in that, The temperature of the high-temperature heat treatment is 1000-1300℃. Preferably, the time of the high-temperature heat treatment is 8-20 h. Preferably, the high-temperature heat treatment is performed in a roller kiln under an air atmosphere.

10. A ternary cathode material, characterized in that, The preparation method is prepared by any one of claims 6-9.

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