Preparation method of high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive electrode material

Abstract

The invention discloses a preparation method of a high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive electrode material. Preparing a mixed metal salt solution of Ni, Co and Mn; atomizing the solution, performing spray pyrolysis at the temperature of 400-600 DEG C, collecting, washing, drying, screening and performing airflow pulverization to obtain a sphere-like precursor; and mixing the precursor with a first lithium source, and carrying out two-stage sintering in an oxygen atmosphere. After cooling, crushing, crushing and screening to obtain the first positive electrode material. And mixing the material with an additive M accounting for 0.3-0.6% of the total mass, and roasting in oxygen at 700-900 DEG C for 4-8 hours to obtain a second positive electrode material. And mixing the material with a second lithium source and an additive N accounting for 0.1-0.5% of the total mass, and roasting at a low temperature of 200-500 DEG C for 4-6 hours to finally prepare the target product LiNixCoyMnzMNO2. The method can effectively improve the capacity performance and preparation efficiency of the material.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion battery cathode materials, and particularly relates to a preparation method of a high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material. BACKGROUND

[0002] Polycrystalline ternary cathode materials have significant advantages in high-energy-density application markets due to their excellent performance in capacity and cycle performance, and have become the mainstream choice for new energy vehicle power batteries. However, during the charging and discharging process of the battery, due to the obvious anisotropy of the material lattice, the shrinkage and expansion along different crystal axis directions are uneven, which causes a large stress inside and easily leads to cracks. After long-term cycling, the material structure may collapse, causing capacity attenuation, affecting the cruising range of electric vehicles and the service life of the battery. In contrast, single-crystal cathode materials have more uniform volume changes during charging and discharging, and the internal grain arrangement is consistent, which is not prone to stress concentration points due to the existence of grain boundaries, and thus has higher structural stability, which can effectively improve the cycle performance and safety performance of new energy vehicle batteries, and has become a key material for promoting the development of the next generation of high-energy-density, long-life power batteries.

[0003] At present, the commonly used preparation methods of ternary cathode materials mainly include solid-phase method, coprecipitation method and sol-gel method, etc. The solid-phase method has problems such as uneven mixing of raw materials, difficulty in controlling particle size and morphology, etc., and it is difficult to meet the extremely high requirements of the high-end new energy power battery market for the consistency and reliability of power batteries; although the coprecipitation method can better control the morphology of the precursor, the process flow is complex and the reaction period is long, resulting in high production cost, which restricts its application in large-scale power battery manufacturing; the sol-gel method has problems such as complex synthesis process, high parameter control requirement, long time consumption and easy carbon residue, etc., and its economic efficiency of large-scale production is poor, which is difficult to meet the demand of new energy vehicle industry for cost reduction and efficiency improvement.

[0004] In contrast, the spray pyrolysis method is relatively simple to operate, has high production efficiency and is easy to scale up, and has obvious economic advantages, which is more in line with the urgent needs of the new energy vehicle industry for low-cost and efficient preparation of cathode materials. The application of the spray pyrolysis method to the preparation of single-crystal ternary cathode materials is expected to effectively make up for the shortcomings of existing methods, promote the development of new energy vehicle power batteries towards more stable performance and lower cost, and has important practical application value and industrialization prospect.

[0005] Therefore, the present application designs a preparation method of a high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material to improve the capacity performance and preparation efficiency of the ternary cathode material. SUMMARY

[0006] The application aims to provide a preparation method of high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive electrode material.

[0007] To achieve the above-mentioned purpose, the application adopts the technical scheme of:

[0008] A preparation method of high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive electrode material, comprising:

[0009] Step one, preparing a mixed metal salt solution of Ni, Co and Mn, wherein the molar ratio of Ni, Co and Mn is (80-98):(1-10):(1-10);

[0010] Step two, atomizing the mixed metal salt solution prepared in step one into mist droplets with a particle size of 10-100 μm by compressed air, and then pyrolyzing the mist droplets in a spray pyrolysis furnace at a temperature of 400-600 ℃; collecting the product by cyclone separation and filter bag, and then washing, drying, screening and airflow crushing to obtain a spherical precursor powder; the general formula of the precursor is Ni x Co y Mn z O2, wherein 0.8≤x≤0.98, 0.01≤y≤0.1, 0

[0011] Step three, mixing the precursor powder prepared in step two with a first lithium source to form a first mixture, wherein the molar ratio of the precursor to the first lithium source is 1:(1.03-1.06); sintering the first mixture in a box furnace by passing oxygen in multiple stages, wherein the first-stage sintering is heated to 400-600 ℃ at a heating rate of 3-5 ℃ / min and kept for 3-6 h; the second-stage sintering is heated to 800-1000 ℃ at a heating rate of 3-5 ℃ / min and kept for 6-10 h; naturally cooling to room temperature, and then mechanically crushing and airflow crushing and screening the material to obtain a first positive electrode material with a general formula of LiNi x Co y Mn z O2;

[0012] Step four, mixing the first positive electrode material prepared in step three with an additive M to form a second mixture, wherein the additive M accounts for 0.3-0.6% of the total mass of the second mixture; high-temperature calcining the second mixture in a box furnace by passing oxygen, wherein the sintering temperature is 700-900 ℃ and the sintering time is 4-8 h; naturally cooling to room temperature, and then airflow crushing and screening the material to obtain a second positive electrode material with a general formula of LiNi x Co y Mn z MO2;

[0013] Step 5: Mix the second cathode material obtained in Step 4 with the second lithium source and additive N to form a third mixture, wherein additive N accounts for 0.1~0.5% of the total mass of the third mixture; calcine the third mixture powder in a box furnace under oxygen conditions at a low temperature of 200~500℃ for 4~6 hours to obtain LiNi. x Co y Mn z MNO2 high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material.

[0014] In a further technical solution, in step one, the total molar concentration of Ni, Co, and Mn in the mixed metal salt solution is 1.8~2.4 mol / L.

[0015] In a further technical solution, in step two, the pressure of the compressed air is 0.4~0.8MPa.

[0016] In a further technical solution, in step two, the general formula is Ni x Co y Mn z The D50 of the near-spherical precursor particles of O2 is 2~4μm, and the Dmax is ≤15μm.

[0017] In a further technical solution, in step three, the first lithium source is at least one of lithium carbonate and lithium hydroxide.

[0018] In a further technical solution, in steps three, four, and five, the purity of the oxygen is greater than 99.99%.

[0019] In a further technical solution, in step four, the additive M is one or more of strontium acetate, strontium nitrate, strontium chloride, strontium carbonate, sodium chloride, potassium chloride, and molybdenum oxide.

[0020] In a further technical solution, in step five, the second lithium source is at least one of lithium alumina, lithium phosphate, and lithium hydroxide, and the second lithium source accounts for 0.4 to 0.6% of the total mass of the third mixture.

[0021] In a further technical solution, in step five, the additive N is one or more of aluminum oxide, zirconium oxide, magnesium oxide, tungsten trioxide, boron trioxide, niobium pentoxide, calcium oxide, and cobalt hydroxyl.

[0022] In a further technical solution, in step five, the general formula is LiNi. x Co y Mn z The D50 of the MNO2 small-particle single-crystal cathode material is 3~5μm, and the Dmax is ≤20μm.

[0023] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0024] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing this case.

[0025] The working principle and advantages of this invention are as follows:

[0026] 1. This invention employs a spray pyrolysis method to prepare high-performance small-particle single-crystal nickel-cobalt-manganese ternary precursors in a one-step process. The resulting product has uniform particle size and controllable morphology. The process is simple, efficient, and suitable for large-scale industrial production, offering significant cost advantages. The synthesized precursor particles are fine and have loose internal pores, which is beneficial for Li... + The rapid diffusion and high reactivity of the precursor effectively reduce the temperature and time required for subsequent calcination, thus saving energy. Especially for high-nickel ternary materials, the precursor prepared by spray pyrolysis can effectively suppress lithium-nickel mixing and improve the structural stability and electrochemical performance of the material.

[0027] 2. This invention employs a multi-sintering process in the preparation of high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode materials. The first sintering stage aims to construct the single-crystal framework: the low-temperature stage promotes the melting of the first lithium source, allowing Li... + Initially, the lithium is uniformly penetrated to the surface of the precursor particles, avoiding localized lithium enrichment or depletion during the high-temperature stage. The high-temperature stage provides sufficient energy to break down the precursor grain boundary barriers, promoting grain fusion to form boundary-free, complete single-crystal particles. Secondary sintering is used to strengthen the crystal structure: high temperature achieves uniform doping of additive M, allowing it to occupy a portion of the Li. + Alternatively, transition metal sites can be added to enhance lattice stability, suppress structural distortion during long-term charge-discharge processes, and improve cycle capacity retention. Simultaneously, the metal elements in additive M form stronger ionic bonds with lattice oxygen, reducing the release rate of lattice oxygen at high temperatures, improving material thermal stability, and reducing safety risks. The third sintering process is primarily used for interface protection: forming a thin and uniform coating layer at a lower temperature avoids damage to the coating structure caused by the first two high-temperature sintering processes and reduces side reactions between the electrolyte and the particle surface during charge-discharge. Furthermore, lithium replenishment is performed during the third sintering process to repair surface lithium defects (such as Li) caused by the first two high-temperature sintering processes. + The "lithium-deficient layer" (caused by volatilization or reaction with the atmosphere) is filled by solid-state diffusion to fill the surface Li. + Vacancies, making the surface Li +The concentration is restored to the bulk level, thereby reducing interfacial impedance and synergistically improving the material's capacity, cycle life, and thermal stability.

[0028] 3. This invention prepares small-particle nickel-cobalt-manganese ternary precursors via spray pyrolysis, resulting in materials with uniform particle size and regular morphology. A complete single-crystal framework is constructed using a multi-stage sintering process, strengthening the crystal structure and reducing the adverse effects of grain boundaries. Specifically, the addition of M during the secondary sintering enhances the structural stability of the material, suppresses volume distortion, and improves safety; the tertiary sintering optimizes the interface, mitigating electrolyte erosion and transition metal dissolution. A lithium replenishment process precisely compensates for lithium loss during sintering, ensuring the integrity of the layered structure and reducing ion mixing. The resulting small-particle single-crystal nickel-cobalt-manganese ternary cathode material possesses comprehensive advantages of high performance, long cycle life, and high safety, meeting the stringent requirements of high-energy-density power batteries for new energy vehicles. This provides crucial material support for upgrading the driving range and enhancing the safety performance of next-generation electric vehicles. Attached Figure Description

[0029] Appendix Figure 1 This is an electron microscope image of the small-particle single-crystal nickel-cobalt-manganese ternary cathode material prepared in Example 1 of the present invention;

[0030] Appendix Figure 2 This is an electron microscope image of the small-particle single-crystal nickel-cobalt-manganese ternary cathode material prepared in Example 2 of the present invention;

[0031] Appendix Figure 3 This is an electron microscope image of the small-particle single-crystal nickel-cobalt-manganese ternary cathode material prepared in Comparative Example 1 of the present invention;

[0032] Appendix Figure 4 This is an electron microscope image of the small-particle single-crystal nickel-cobalt-manganese ternary cathode material prepared in Comparative Example 2 of this invention;

[0033] Appendix Figure 5 This is an electron microscope image of the small-particle single-crystal nickel-cobalt-manganese ternary cathode material prepared in Comparative Example 3 of the present invention;

[0034] Appendix Figure 6 The diagram shows the cycle performance of the batteries prepared in Example 1, Comparative Examples 2 and 3 of this invention under the conditions of 45°C and discharge current density of 1C, with a voltage window of 3.0-4.35V. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0036] The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the embodiments of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0037] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0038] Example 1:

[0039] Step 1: Prepare a mixed metal salt solution of Ni, Co, and Mn in a molar ratio of 87:4:9, wherein the total molar concentration of Ni, Co, and Mn is 2.0 mol / L;

[0040] Step 2: The mixed metal salt solution obtained in Step 1 is atomized into 70μm droplets using compressed air at 0.5MPa, and then pyrolyzed in a spray pyrolysis furnace at 500℃. The product is then separated by cyclone separator and collected by filter bag, followed by washing, drying, sieving, and air jet milling to obtain a near-spherical precursor powder. The precursor has the general formula Ni. 0.87 Co 0.04 Mn 0.09 O2, D50 is 2.0μm, Dmax is 13.4μm;

[0041] Step 3: Mix the precursor powder obtained in Step 2 with lithium hydroxide at a molar ratio of 1:1.05 to form a first mixture. Perform multi-stage sintering of the first mixture in a box furnace by introducing oxygen at a concentration of 99.99%. The first stage of sintering involves heating to 500°C at a heating rate of 3°C / min and holding for 5 hours. The second stage of sintering involves heating to 800°C at a heating rate of 5°C / min and holding for 8 hours. After natural cooling to room temperature, the material is then mechanically crushed, air-jet pulverized, and sieved to obtain the general formula LiNi. 0.87 Co 0.04 Mn 0.09 The primary cathode material for O2;

[0042] Step 4: The first cathode material obtained in Step 3 is mixed with strontium carbonate to form a second mixture, with strontium carbonate accounting for 0.4% of the total mass of the second mixture. The second mixture is then subjected to high-temperature calcination in a box furnace with oxygen introduced, at a sintering temperature of 900℃ for 4 hours. After natural cooling to room temperature, the material is then subjected to air jet milling and sieving to obtain Sr-doped LiNi. 0.87 Co 0.04 Mn 0.09 SrO2 is the second cathode material;

[0043] Step 5: The second cathode material obtained in Step 4 is mixed with lithium hydroxide, boron oxide, and tungsten trioxide to form a third mixture. The doping amounts are 0.5% (lithium hydroxide), 0.1% (boron oxide), and 0.4% (tungsten trioxide) of the total mass of the third mixture, respectively. The third mixture is then subjected to low-temperature calcination in a box furnace with oxygen purging. The sintering temperature is 450℃, and the sintering time is 6 hours to obtain coated and doped small-particle LiNi. 0.87 Co 0.04 Mn 0.09 The cathode material of SrBWO2 has a D50 of 3.9 μm and a Dmax of 18.7 μm.

[0044] Example 2:

[0045] Step 1: Prepare a mixed metal salt solution of Ni, Co, and Mn in a molar ratio of 87:4:9, wherein the total molar concentration of Ni, Co, and Mn is 2.0 mol / L;

[0046] Step 2: The mixed metal salt solution obtained in Step 1 is atomized into 70μm droplets using compressed air at 0.5MPa, and then pyrolyzed in a spray pyrolysis furnace at 500℃. The product is then separated by cyclone separator and collected by filter bag, followed by washing, drying, sieving, and air jet milling to obtain a near-spherical precursor powder. The precursor has the general formula Ni. 0.87 Co 0.04 Mn 0.09 O2, D50 is 2.5μm, Dmax is 13.8μm;

[0047] Step 3: Mix the precursor powder obtained in Step 2 with lithium hydroxide at a molar ratio of 1:1.05 to form a first mixture. Perform multi-stage sintering of the first mixture in a box furnace by introducing oxygen at a concentration of 99.99%. The first stage of sintering involves heating to 500°C at a rate of 3°C / min and holding for 5 hours. The second stage of sintering involves heating to 800°C at a rate of 5°C / min and holding for 8 hours. After natural cooling to room temperature, the material is then mechanically crushed and subjected to air jet milling, followed by sieving to obtain the chemical formula LiNi. 0.87 Co 0.04 Mn 0.09 The primary cathode material for O2;

[0048] Step 4: The first cathode material obtained in Step 3 is mixed with strontium carbonate to form a second mixture, with strontium carbonate accounting for 0.4% of the total mass of the second mixture. The second mixture is then subjected to high-temperature calcination in a box furnace with oxygen introduced, at a sintering temperature of 900℃ for 6 hours. After natural cooling to room temperature, the material is then subjected to air jet milling and sieving to obtain Sr-doped LiNi. 0.87 Co 0.04 Mn 0.09 SrO2 is the second cathode material;

[0049] Step 5: The second cathode material obtained in Step 4 is mixed with lithium hydroxide and cobalt hydroxyl to form a third mixture. The doping amounts are 0.5% (lithium hydroxide) and 0.3% (cobalt hydroxyl) of the total mass of the third mixture, respectively. The third mixture is then subjected to low-temperature calcination in a box furnace with oxygen purging. The sintering temperature is 450°C and the sintering time is 6 hours to obtain coated and doped small-particle LiNi. 0.87 Co 0.04 Mn 0.09 The cathode material is SrCoO2, with a D50 of 4.6 μm and a Dmax of 19.5 μm.

[0050] Comparative Example 1:

[0051] Step 1: Prepare a mixed metal salt solution of Ni, Co, and Mn with a molar ratio of 87:4:9, wherein the total molar concentration of Ni, Co, and Mn is 2.0 mol / L;

[0052] Prepare a sodium hydroxide solution with a molar concentration of 9 mol / L as a precipitant;

[0053] Prepare an ammonia solution with a molar concentration of 2.7 mol / L as a complexing agent;

[0054] Step 2: Add a mixed metal salt solution, precipitant, and complexing agent to the reactor. Maintain the pH at 11.4–12.0, the reaction temperature at 60°C, and the reactor rotation speed at 400 r / min. Continuously purge with nitrogen or an inert gas during the reaction. After 65 hours of reaction, filter, wash, dry, and crush the reaction slurry to obtain a near-spherical precursor powder. The precursor has the general formula Ni. 0.87 Co 0.04 Mn 0.09 (OH)2, D50 is 3.5 μm, Dmax is 8.2 μm;

[0055] Steps three, four, and five are the same as in Example 1. Small LiNi particles with coating and doping are obtained. 0.87 Co 0.04 Mn 0.09 The cathode material of SrBWO2 has a D50 of 4.0 μm and a Dmax of 13.1 μm.

[0056] Comparative Example 2:

[0057] Steps one and two are the same as in Example 1; the resulting precursor oxide material Ni 0.87 Co 0.04 Mn 0.09 O2 has a D50 of 2.8 μm and a Dmax of 14.1 μm;

[0058] Step 3: The precursor powder obtained in Step 2 is mixed uniformly with lithium hydroxide and strontium carbonate to form the first mixture. The molar ratio of precursor powder to lithium hydroxide is 1:1.05, and strontium carbonate accounts for 0.4% of the total mass of the first mixture. The obtained first mixture is subjected to multi-stage sintering in a box furnace with oxygen at a concentration of 99.99%. The first stage of sintering involves heating to 500°C at a heating rate of 3°C / min and holding for 5 hours. The second stage of sintering involves heating to 900°C at a heating rate of 5°C / min and holding for 8 hours. After natural cooling to room temperature, the material is then mechanically crushed, air-jet pulverized, and sieved to obtain Sr-doped LiNi. 0.87 Co 0.04 Mn 0.09 The cathode material of SrO2 has a D50 of 5.7 μm and a Dmax of 22.4 μm.

[0059] Comparative Example 3:

[0060] Steps one and two are the same as in Example 1, and the resulting precursor oxide material Ni 0.87 Co 0.04 Mn 0.09 O2 has a D50 of 2.4 μm and a Dmax of 14.7 μm;

[0061] Step 3: The precursor powder obtained in Step 2 is mixed uniformly with lithium hydroxide to form the first mixture, with a molar ratio of precursor powder to lithium hydroxide of 1:1.05. The resulting first mixture is then subjected to multi-stage sintering in a box furnace with 99.99% oxygen. The first stage of sintering involves heating to 500℃ at a rate of 3℃ / min and holding for 5 hours. The second stage of sintering involves heating to 900℃ at a rate of 5℃ / min and holding for 8 hours. After natural cooling to room temperature, the material is then mechanically crushed and subjected to air jet milling, followed by sieving to obtain LiNi. 0.87 Co 0.04 Mn 0.09 The cathode material for O2 has a D50 of 8.3 μm and a Dmax of 37.2 μm.

[0062] Electrochemical performance data of small-particle single-crystal nickel-cobalt-manganese ternary cathode materials prepared in Examples 1-2 and Comparative Examples 1-3 are shown in Table 1; wherein, the voltage window is 3.0-4.35V, the rate test is carried out at 25℃, and the cycle test is carried out at 45℃.

[0063] Table 1. Electrochemical performance of small-particle single-crystal nickel-cobalt-manganese ternary cathode materials in the examples and comparative examples:

[0064] Table 1 shows that the small-particle nickel-cobalt-manganese ternary cathode materials prepared by the spray method in Examples 1 and 2, and by the co-precipitation method in Comparative Example 1, exhibit significant single-crystal formation and good dispersibility (see Table 1).Figure 1 , Figure 2 and Figure 3 ), within a voltage window of 3.0V-4.35V (see Figure 6 The 0.1C discharge specific capacity is similar, and the cycle performance is good. However, the coprecipitation method is complex, has a long reaction time, and high production cost, while the spray pyrolysis method is simple to operate, easy to mass-produce, and has a cost advantage.

[0065] like Figure 4 As shown in Comparative Example 2, small-particle single-crystal nickel-cobalt-manganese ternary cathode material was obtained by directly mixing the precursor, lithium hydroxide, and strontium carbonate through a single two-stage sintering process. Comparing Example 1 and Comparative Example 2, it can be seen that the single-crystal cathode material obtained by single-sintering has a rough particle surface and residual impurities. The temperature range of single-sintering cannot meet the multi-stage requirements of single-crystal growth, and adjacent particles are prone to sintering adhesion, forming multi-particle agglomeration, making it difficult to control particle size and morphology. The data in Table 1 show that the single-crystal cathode "single-stage sintering" process has a significant impact on the electrochemical performance of the material, resulting in reduced initial discharge specific capacity, insufficient rate performance, and rapid degradation of cycle performance.

[0066] like Figure 5 As shown in Comparative Example 3, the precursor and lithium hydroxide were directly mixed and sintered in a single two-stage process to obtain small-particle single-crystal nickel-cobalt-manganese ternary cathode material. Comparing Example 1 and Comparative Example 3, it can be seen that some particles of the material obtained by the "single-stage sintering + Sr-free" process formed ultra-large single crystals due to excessively rapid growth, while others remained small due to limited growth, resulting in a widened particle size distribution. The data in Table 1 shows that the "single-stage sintering + Sr-free" process for single-crystal cathodes cannot effectively control grain growth and weakens the stability of the crystal structure, ultimately leading to a comprehensive decrease in the product's energy density, rate performance, and cycle life.

[0067] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. Step two, the mixed metal salt solution prepared in step one is atomized by compressed air into mist droplets with a particle size of 10-100 μm, and then pyrolyzed in a spray pyrolysis furnace at a temperature of 400-600 ℃. The product is collected by cyclone separation and filter bag, and then washed, dried, sieved, and airflow pulverized to obtain a spherical precursor powder. The general formula of the precursor is Ni x Co y Mn z O2, wherein 0.8≤x≤0.98, 0.01≤y≤0.1, 0 z≤0.1, and x+y+z=1. Step three, mixing the precursor powder prepared in step two with a first lithium source to form a first mixture, wherein the molar ratio of the precursor to the first lithium source is 1:(1.03-1.06); sintering the first mixture in a box furnace in multiple stages with oxygen, wherein the first stage sintering is heated to 400-600°C at a heating rate of 3-5°C / min, and the temperature is maintained for 3-6h; the second stage sintering is heated to 800-1000°C at a heating rate of 3-5°C / min, and the temperature is maintained for 6-10h; naturally cooling to room temperature, and then mechanically crushing and air-jet milling and sieving the material to obtain a first positive electrode material of formula LiNi x Co y Mn z O2. Step 4: Mix the first cathode material obtained in Step 3 with additive M to form a second mixture, where additive M accounts for 0.3-0.6% of the total mass of the second mixture. The second mixture is then subjected to high-temperature calcination in a box furnace with oxygen introduced, at a sintering temperature of 700-900℃ for 4-8 hours. After natural cooling to room temperature, the material is then subjected to air-jet milling and sieving to obtain the general formula LiNi. x Co y Mn z The second cathode material for MO2; Step five, the second positive material prepared in step four is mixed with a second lithium source and an additive N to form a third mixture, the additive N accounting for 0.1-0.5% of the total mass of the third mixture; the third mixed powder is subjected to low-temperature calcination in a box furnace with oxygen, the sintering temperature being 200-500°C, and the sintering time being 4-6h, to obtain a high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive material of formula LiNi x Co y Mn z MNO2.

2. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary positive electrode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

3. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

4. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: In step two, the general formula is Ni x Co y Mn z The D50 of the quasi-spherical precursor particles of O2 is 2-4 μm, and Dmax≤15 μm.

5. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

6. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

7. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

8. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material.

9. The preparation method of the high-performance small-particle single-crystal nickel-cobalt-manganese ternary cathode material according to claim 1, characterized in that: The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode material. The application relates to a preparation method of a lithium ion battery positive electrode 10. The method according to claim 1, wherein the method is characterized by: In step five, the general formula is LiNi x Co y Mn z The D50 of the small particle monocrystal positive electrode material MNO2 is 3-5 μm, and Dmax≤20 μm.

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