Rate type ultra-high nickel precursor material and preparation method thereof, and positive electrode material

Abstract

The invention relates to a rate type ultrahigh nickel precursor material and a preparation method thereof, and a positive electrode material prepared from the precursor material. By regulating and controlling a complexing agent system, reaction conditions and additives in stages, accurate construction of the core-shell structure ultrahigh nickel precursor material with the interior growing along the (001) orientation and arranged in a needle shape and the shell growing along the (010) orientation is achieved. The internal needle-shaped arranged (001) oriented growth primary particles provide an ordered lithium ion transmission channel, so that rapid transmission in a lithium ion bulk phase is guaranteed; the oriented growth primary particles of the shell (010) provide more lithium ion embedding sites, and material polarization is reduced. Through the construction of the core-shell oriented growth structure, the material shows excellent rate capability and cycling stability. According to the invention, a one-step coprecipitation method is combined with a simple post-treatment process, additional equipment or complex post-treatment is not needed, and the method is adaptive to an existing lithium battery positive electrode precursor production line and is easy for industrial production.

Description

Technical Field

[0001] The present invention belongs to the technical field of lithium-ion batteries, relates to a cathode material precursor, and particularly relates to a high-rate ultra-high nickel precursor material and a preparation method thereof, and a cathode material prepared from the precursor material. Background Art

[0002] With the continuous growth of the demand for high-energy density batteries in new energy vehicles, ultra-high nickel ternary cathode materials (Ni≥90%) have become a research hotspot due to their theoretical capacity of up to 280 mAh / g. However, the kinetic performance of ultra-high nickel ternary cathode materials is sluggish during the cycling process, which easily leads to an uneven concentration distribution of lithium ions, induces the formation of internal stress and cracks, and further causes capacity attenuation and safety hazards.

[0003] To solve the above problems, the core-shell structure design has become the key. The core-shell structure can buffer volume expansion, inhibit side reactions and improve cycling stability by coating a shell (low nickel or stable phase) on the surface of the core (high nickel active material). For example, the patent CN112968153B of Tianjin Bamo Technology enhances the connection force between the core and the shell through an interlayer design, significantly improving the cycling performance. However, the existing core-shell structure precursors do not solve the kinetic performance of the materials, and the materials still face the problem of slow lithium ion diffusion rate.

[0004] In view of this, the present invention combines the regulation of process parameters in stages with the complexing agent synergistic strategy to propose a preparation method for a high-rate ultra-high nickel precursor material, significantly improving the kinetic performance of the material. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the present invention provides a high-rate ultra-high nickel precursor material and a preparation method thereof, which adopt the regulation of process parameters in stages and the complexing agent synergistic strategy, and precisely construct a core-shell structure ultra-high nickel precursor material with a (001) orientation growth and needle-like arrangement of the core and a (010) orientation growth doped with Zr / Al of the shell through a one-step coprecipitation method, significantly improving the kinetic performance of the material.

[0006] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0007] In the first aspect, the present invention provides a high-rate ultra-high nickel precursor, which is characterized in that its chemical general formula is Ni(OH)2@Ni x Zr y Al z (OH) 2+δ, where 0.9 ≤ x ≤ 0.98, 0 < y ≤ 0.05, 0 < z ≤ 0.05, and δ is an electro-neutrality adjustment factor; the precursor material has a core-shell oriented growth structure, with its inner core being needle-like arranged primary particles growing in the (001) orientation and the outer shell being primary particles growing in the (010) orientation; the particle size ratio of the inner core to the outer shell of the precursor material is (1 - 20):1, the median particle size D50 of the inner core is 4 μm - 10 μm, and the thickness of the outer shell is 0.5 μm - 2 μm.

[0008] In a second aspect, the present invention provides a method for preparing a high-rate ultra-high nickel precursor material, and the preparation method includes the following steps:

[0009] (1) Inner core growth stage: Under a protective atmosphere, a Ni unit salt solution, a first complexing agent solution, and a precipitating agent solution are added in parallel to the bottom liquid for nucleation and inner core growth reaction to obtain a pure Ni(OH)2 precursor slurry with the inner core growing in the (001) orientation and arranged in a needle-like shape.

[0010] (2) Outer shell growth stage: Under a protective atmosphere, the Ni unit salt solution is switched to a Ni / Zr / Al ternary salt solution, and a second complexing agent solution, a precipitating agent solution, and an additive are continuously added to form an outer shell structure growing in the (101) orientation. After reaching the target particle size, the reaction is stopped to obtain a precursor slurry with a core-shell oriented growth structure.

[0011] (3) Post-treatment stage: The slurry is washed and dried to obtain a high-rate ultra-high nickel precursor with a core-shell oriented growth structure.

[0012] Preferably, the first complexing agent solution includes a urea solution containing ammonia water; the second complexing agent solution includes ammonia water, urea, and an additive, and the additive includes at least one of citric acid, oxalic acid, or ethylenediaminetetraacetic acid.

[0013] Preferably, the ammonia water concentration in the first and second complexing agent solutions is 2 wt% - 20 wt%, for example, it can be 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%, 16 wt%, 18 wt%, or 20 wt%; however, it is not limited to the listed values, and the remaining unlisted values within the numerical range are equally applicable.

[0014] Preferably, the urea concentration in the first and second complexing agent solutions is 0.2 mol / L - 2 mol / L, for example, it can be 0.2 mol / L, 0.4 mol / L, 0.6 mol / L, 0.8 mol / L, 1.0 mol / L, 1.2 mol / L, 1.4 mol / L, 1.6 mol / L, 1.8 mol / L, or 2.0 mol / L; however, it is not limited to the listed values, and the remaining unlisted values within the numerical range are equally applicable.

[0015] Preferably, the additive concentration in the second complexing agent solution is 0.1 wt% to 3 wt%, for example, it can be 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt% or 3 wt%, but is not limited to the listed values, and the other unlisted values within the numerical range are equally applicable.

[0016] Preferably, the Ni salt in the mixed Ni unit salt solution in step (1) includes any one or a combination of at least two of nickel sulfate, nickel nitrate or nickel chloride. Typical but non-limiting combinations include the combination of nickel sulfate and nickel nitrate, the combination of nickel sulfate and nickel chloride, the combination of nickel nitrate and nickel chloride, or the combination of nickel sulfate, nickel nitrate and nickel chloride. Nickel sulfate is preferred.

[0017] Preferably, the total concentration of Ni ions in the Ni unit salt solution in step (1) is 1 mol / L to 3 mol / L, for example, it can be 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L or 3 mol / L, but is not limited to the listed values, and the other unlisted values within the numerical range are equally applicable.

[0018] Preferably, the Ni salt in the Ni / Zr / Al ternary salt solution in step (2) includes any one or a combination of at least two of nickel sulfate, nickel nitrate or nickel chloride, the Zr salt includes any one or a combination of at least two of zirconium sulfate, zirconium nitrate or zirconium chloride, and the Al salt includes any one or a combination of at least two of aluminum sulfate, aluminum nitrate or aluminum chloride. Sulfates are more preferred.

[0019] Preferably, the total concentration of metal ions in the Ni / Zr / Al ternary salt solution in step (2) is 1 mol / L to 3 mol / L, for example, it can be 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L or 3 mol / L, but is not limited to the listed values, and the other unlisted values within the numerical range are equally applicable.

[0020] Preferably, the precipitant in the precipitant solution in step (1) includes any one or a combination of at least two of sodium hydroxide, potassium hydroxide, lithium hydroxide or sodium carbonate. Typical but non-limiting combinations include the combination of super nickel and potassium hydroxide, the sum of potassium hydroxide and lithium hydroxide, the combination of lithium hydroxide and sodium carbonate, or the combination of sodium hydroxide, potassium hydroxide, lithium hydroxide and sodium carbonate.

[0021] Preferably, the concentration of the precipitant in the precipitant solution in steps (1) and (2) is 10 wt% to 40 wt%. For example, it can be 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0022] Preferably, the bottom solution in step (1) is a mixed solution of a precipitant solution, ammonia water, urea, and water; the pH value of the bottom solution is 12 to 13, the ammonia concentration is 0.5 g / L to 2 g / L, and the concentration of urea is 0.2 mol / L to 2 mol / L.

[0023] Preferably, the gas used in the protective atmosphere in steps (1) and (2) includes nitrogen and / or inert gas.

[0024] Preferably, the pH value of the reaction in the core growth stage in step (1) is 9 to 10.5, the ammonia concentration is 0.5 g / L to 2 g / L, the temperature is 40 to 60 °C, and the stirring speed is 400 rpm to 600 rpm.

[0025] Preferably, the median particle size D50 of the core in step (1) is 4 μm to 10 μm.

[0026] Preferably, the pH in the shell growth stage in step (2) is 10 to 11, the ammonia concentration is 2 g / L to 4 g / L, the temperature is 50 to 70 °C, and the stirring speed is 200 rpm to 400 rpm.

[0027] Preferably, the thickness of the shell in step (2) is 0.5 μm to 2 μm.

[0028] Preferably, the post-treatment in step (3) includes washing and drying in sequence.

[0029] Preferably, the temperature of the drying is 80 °C to 150 °C. For example, it can be 80 °C, 90 °C, 100 °C, 120 °C, or 150 °C, but is not limited to the listed values. The other unlisted values within the numerical range are equally applicable.

[0030] Preferably, the end point of the drying is that the moisture content reaches below 0.8 wt%.

[0031] In the third aspect, the present invention provides a cathode material, which is prepared from the rate-type ultra-high nickel precursor described in the second aspect.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) The primary particles of the precursor material prepared by the present invention grow in the (001) orientation inside and are arranged in a needle-like shape, while the outer shell is composed of primary particles growing in the (010) orientation. Among them, the growth in the (001) orientation and the needle-like arrangement ensure the rapid migration of lithium ions in the bulk phase; the growth in the (010) orientation provides more transmission channels for the insertion / extraction of lithium ions, improving the kinetic properties of lithium ion transmission from the inside out and having excellent high-rate performance.

[0034] (2) The pH, ammonia concentration, and temperature in the outer shell growth stage of the present invention are all higher than those in the inner core growth stage. The purpose is to make the three elements of Ni / Zr / Al in the outer shell co-precipitate more uniformly and form a denser microstructure; while the stirring speed in the outer shell growth stage is lower than that in the inner core growth stage to ensure that when the particles of the precursor are larger, cracks or small particles will not occur due to too high a stirring speed.

[0035] (3) The present invention adopts a one-step co-precipitation method combined with a simple post-treatment process, without additional equipment or complex post-treatment, and is compatible with the existing lithium-ion battery cathode precursor production line, making it easy for industrial production. Description of the Drawings

[0036] Figure 1 SEM image of the core-shell oriented growth structure ultra-high nickel precursor obtained in Example 1.

[0037] Figure 2 Cross-sectional SEM image of the core-shell oriented growth structure ultra-high nickel precursor obtained in Example 1. Detailed Description of the Invention

[0038] The technical solutions of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations of the present invention.

[0039] Example 1

[0040] This example provides a preparation method for a core-shell oriented growth structure ultra-high nickel precursor, and the preparation method includes the following steps:

[0041] (1) According to Ni(OH)2@Ni 0.95 Zr 0.02 Al 0.03 (OH) 2.07Prepare a nickel sulfate solution (core) and a mixed metal sulfate solution (shell) separately, with the total concentration of metal ions being 2 mol / L; prepare a mixed solution with an ammonia water concentration of 10 wt% and a urea concentration of 1 mol / L as the first complexing agent solution; prepare a mixed solution with an ammonia water concentration of 10 wt%, a urea concentration of 1 mol / L, and an ethylenediaminetetraacetic acid concentration of 1 wt% as the second complexing agent solution; prepare a sodium hydroxide solution with a concentration of 25 wt% as the precipitant solution; use sodium hydroxide solution, concentrated ammonia water, urea, and water to prepare a reaction bottom solution with a pH value of 12.8, an ammonia concentration of 1.2 g / L, and a urea concentration of 1 mol / L;

[0042] (2) Under the protection of a nitrogen atmosphere, the nickel sulfate solution, the first complexing agent solution, and the sodium hydroxide solution are respectively fed into a 50 L reaction kettle containing the bottom solution at a flow rate of 1.5 L / h, 0.64 L / h, and 0.20 L / h for coprecipitation reaction. During the nucleation stage, control the pH = 12.7 ± 0.1 and maintain it for 6 h; after the nucleation is completed, adjust the flow rate of the sodium hydroxide solution to make the pH of the reaction system drop at a rate of 0.2 / h to the target pH = 9.8 ± 0.1 in the core growth stage, and continue the reaction until the median particle size D50 of the pure Ni(OH)2 core reaches 7 μm and then pause the reaction; the ammonia concentration in this stage is controlled at 1.2 ± 0.3 g / L, the reaction temperature is controlled at 55 ± 1 °C, and the stirring speed is controlled at 500 rpm;

[0043] (3) After the core growth stage is completed, switch the nickel sulfate solution to the mixed metal sulfate solution and the first complexing agent solution to the second complexing agent solution, and adjust the feeding flow rates of the sodium hydroxide solution and the second complexing agent to gradually raise the pH of the reaction system to pH = 10.5 ± 0.1 in the shell growth stage and gradually increase the ammonia concentration to 3 ± 0.3 g / L. Continue the reaction until the median particle size D50 of the particles reaches 8 μm and then stop the reaction to obtain a core-shell oriented growth structure ultra-high nickel precursor slurry; the reaction temperature in this stage is controlled at 62 ± 1 °C, and the stirring speed is controlled at 300 rpm;

[0044] (4) The obtained slurry is washed repeatedly and dried at 100 °C for 12 h to obtain the core-shell oriented growth structure ultra-high nickel precursor Ni(OH)2@Ni 0.95 Zr 0.02 Al 0.03 (OH) 2.07 ;

[0045] Figure 1 is the SEM image of the core-shell oriented growth structure ultra-high nickel precursor obtained in this example, Figure 2 is the cross-sectional SEM image of the core-shell oriented growth structure ultra-high nickel precursor obtained in this example. From Figure 1It can be seen that through the staged regulation of the complexing agent system and reaction conditions, the present invention realizes the precise construction of a core-shell structure with (001) orientation growth of the core and needle-like arrangement, and (010) orientation growth of the Zr / Al co-doped shell, as well as the precise regulation of the microstructure of the precursor, and finally obtains a core-shell orientation growth structure ultra-high nickel precursor with good sphericity, good dispersibility and no internal cracks.

[0046] Example 2 (EDTA in the outer shell growth stage is switched to citric acid, and the cycling and rate performance are reduced)

[0047] This example provides a method for preparing an ultra-high nickel precursor with a core-shell orientation growth structure. Except that the organic acid additive in the second complexing agent solution is replaced with citric acid in an equal mass amount to ethylenediaminetetraacetic acid, the rest are the same as in Example 1.

[0048] Example 3 (the thickness of the outer shell exceeds the range value, and the capacity is reduced)

[0049] This example provides a method for preparing an ultra-high nickel precursor with a core-shell orientation growth structure. Except that the thickness of the outer shell is increased from 1 μm to 3 μm (the median particle size during shutdown is 10 μm), the rest are the same as in Example 1.

[0050] Example 4 (the Zr / Al double doping of the outer shell is switched to Al single doping, and the rate performance is reduced due to the lack of Li2ZrO3 on the surface)

[0051] This example provides a method for preparing an ultra-high nickel precursor with a core-shell orientation growth structure. Except that the mixed metal salt solution used for the outer shell is switched from a Ni / Zr / Al ternary solution to a Ni / Al binary solution (the molar ratio of Ni:Al is 95:5), the rest are the same as in Example 1.

[0052] Example 5 (the content of Zr / Al double doping in the outer shell exceeds the range value, and the capacity is greatly reduced)

[0053] This example provides a method for preparing an ultra-high nickel precursor with a core-shell orientation growth structure. Except that the mixed metal salt solution used for the outer shell is switched from a Ni / Zr / Al ternary solution (the molar ratio of Ni:Zr:Al is 95:2:3) to a Ni / Zr / Al ternary solution (the molar ratio of Ni:Zr:Al is 88:6:6), the rest are the same as in Example 1.

[0054] Example 6 (the pH / NH3 in the outer shell growth stage exceeds the range value, and the rate and cycling stability are reduced)

[0055] This example provides a method for preparing an ultra-high nickel precursor with a core-shell orientation growth structure. Except that the pH in the outer shell growth stage is increased to 11.2 ± 0.1 and the ammonia concentration is increased to 5 ± 0.3 g / L, the rest are the same as in Example 1.

[0056] Example 7 (Urea solution is not added to the reaction bottom liquid and the complexing agent in the core / shell growth stage, resulting in reduced rate and cycling stability)

[0057] This example provides a method for preparing a core-shell oriented growth structure ultra-high nickel precursor. Except that urea is not added to the reaction bottom liquid and the complexing agent in the core / shell growth stage, the rest are the same as in Example 1.

[0058] Comparative Example 1 (The shell is not doped with Zr / Al)

[0059] This comparative example provides a method for preparing a core-shell oriented growth structure ultra-high nickel precursor. Except that the shell growth stage is not doped with Zr / Al (the Ni / Zr / Al ternary solution is switched to the Ni unit solution), the rest are the same as in Example 1.

[0060] Comparative Example 2 (No additive is used in the shell growth stage)

[0061] This comparative example provides a method for preparing a core-shell oriented growth structure ultra-high nickel precursor. Except that no organic acid additive is used in the shell growth stage, the rest are the same as in Example 1.

[0062] Comparative Example 3 (The pH / NH3 / temperature / stirring speed in the shell growth stage are maintained the same as in the core growth stage, resulting in reduced rate and cycling stability)

[0063] This comparative example provides a method for preparing an ultra-high nickel precursor with (001) oriented growth throughout the particle. Except that the pH, ammonia concentration, reaction temperature, and stirring speed in the shell growth stage are the same as those in the core growth stage, the rest are the same as in Example 1.

[0064] The precursor obtained by the present invention and its cross-section were tested using a scanning electron microscope. The SEM image of the core-shell oriented growth structure ultra-high nickel precursor provided in Example 1 is as Figure 1 shown, and the cross-sectional SEM image is as Figure 2 shown; from Figure 1 and Figure 2 it can be seen that the ultra-high nickel precursor provided in Example 1 has a good spherical shape, good dispersibility in microstructure, and a crack-free core-shell heterostructure inside.

[0065] Performance Characterization

[0066] The core-shell oriented growth structure ultra-high nickel precursor was prepared by the preparation methods provided in the above examples and comparative examples. The obtained core-shell oriented growth structure ultra-high nickel precursor and lithium hydroxide were mixed at a mass ratio of 1:1.04 and sintered at 780 °C for 16 h to obtain a cathode material;

[0067] The obtained cathode material was used to prepare a lithium-ion battery: the obtained cathode material, conductive carbon black SP (TIMCAL), and polyvinylidene fluoride PVDF (HSV900) were mixed at a mass ratio of 90:5:5. N-methylpyrrolidone was used as the solvent, and the mixture was stirred into a slurry. The obtained slurry was evenly coated on an aluminum foil with a doctor blade having a coating gap of 100 μm; after coating, it was first dried by blowing air, then roll-pressed and cut into circular electrode sheets, and then vacuum-dried at 120 °C and the weight of the electrode sheets was measured to obtain the cathode electrode sheets for the coin half-cells; a metal lithium sheet was selected as the anode, a PP microporous membrane was selected as the separator, and a lithium battery basic electrolyte was selected as the electrolyte. The cathode electrode sheet, metal lithium sheet, separator, and electrolyte were assembled to obtain a coin cell;

[0068] The battery was tested using a battery test system (BlueTEC CT2001A, Wuhan, China). First, it was activated 3 times at a rate of 0.1C / 2.7 - 4.3V, and then the activated coin cell was subjected to electrochemical performance tests under the conditions of 2.7 - 4.3V@0.1C / 1C. The test results are shown in Table 1.

[0069] Table 1

[0070]

[0071]

[0072] It can be seen from Table 1 that:

[0073] (1) The lithium-ion batteries prepared with the core-shell oriented growth structure ultra-high nickel precursors prepared by the preparation methods provided in Examples 1 - 7 all have relatively high initial discharge capacities, excellent rate performance, and good cycle stability;

[0074] (2) By comparing Example 1 with Examples 2 and Comparative Example 2, it can be seen that whether and what type of additives are used in the outer shell growth stage of the present invention will affect the performance of the battery; among them, the influence on the performance is ethylenediaminetetraacetic acid > citric acid > no additive. This is because when there are additives that have strong complexation with Zr and Al, combined with the control of other reaction conditions, a Zr / Al double-doped outer shell layer with better crystallinity and uniform doping growing along the (010) orientation can be obtained, thus significantly affecting the kinetic performance of the material and improving various electrical properties;

[0075] (3) By comparing Example 1 with Example 3, it can be seen that the outer shell growth thickness in the present invention will affect the performance of the battery. When the outer shell thickness containing Zr / Al double doping is relatively thick, although it can improve the rate performance of the material, it will appropriately reduce the cycle stability;

[0076] (4) It can be seen from the comparison between Example 1 and Example 4 and Comparative Example 1 that whether the outer shell in the present invention is Zr / Al double-doped, single-doped or undoped will affect the performance of the battery. Among them, the effect on performance is Zr / Al double-doping > Zr or Al single-doping > no doping. This is mainly because the doping of Zr and Al will significantly affect the electronic structure, interfacial bonding strength, cation mixing, distribution of lattice stress and inhibition of phase transformation of the material. When there is doping, the performance of the battery will be significantly improved; while in the case of double-doping, since a mixed lithium ion conductor containing Li2ZrO3 and LiAlO2 will be formed on the surface during the sintering process of the cathode material, the influence on the material structure is more obvious than that of single-doping. Therefore, the rate performance and cycling performance are better in the case of double-doping than in single-doping;

[0077] (5) It can be seen from the comparison between Example 1 and Example 5 that the content of Zr / Al double-doping in the outer shell in the present invention will affect the performance of the battery. This is mainly because Zr or Al itself is an inactive substance and does not participate in the chemical reaction process of charge and discharge. Excessive doping amount will significantly reduce the discharge capacity and affect its cycling stability;

[0078] (6) It can be seen from the comparison between Example 1 and Comparative Example 3 that if the whole particle grows in the (001) orientation, it will hinder the migration of lithium ions at the interface, thereby affecting the electrochemical performance.

[0079] (7) It can be seen from the comparison between Example 1 and Example 7 that the reaction bottom liquid and the urea solution in the complexing agent in the core / shell growth stage in the present invention will affect the performance of the battery. Among them, urea mainly affects the stability of ammonia concentration and solution pH value by slowly releasing ammonia through hydrolysis. In the presence of urea, the crystallization conditions can be improved, and the slow and uniform growth of the precursor crystal can be promoted, thereby improving its cycling stability and rate performance.

[0080] The applicant declares that the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A rate-type ultra-high nickel precursor material, characterized in that: The chemical general formula of the precursor material is Ni(OH)2@Ni x Zr y Al z (OH) 2+δ , where 0.9 ≤ x ≤ 0.98, 0 < y ≤ 0.05, 0 < z ≤ 0.05, and δ is an electro-neutrality adjustment factor; the precursor material has a core-shell oriented growth structure, with its inner core being needle-like arranged primary particles growing in the (001) orientation and the outer shell being primary particles growing in the (010) orientation; the particle size ratio of the inner core to the outer shell of the precursor material is (1-20):1, the median particle size D50 of the inner core is 4 μm to 10 μm, and the thickness of the outer shell is 0.5 μm to 2 μm.

2. The preparation method of the high-rate ultra-high nickel precursor according to claim 1, characterized in that, It includes the following steps: (1) Core growth stage: Under a protective atmosphere, a Ni unit salt solution, a first complexing agent solution, and a precipitant solution are added in parallel to a bottom liquid to carry out nucleation and core growth reactions, obtaining a pure Ni(OH)₂ precursor slurry with a (001) orientation growth and arranged in a needle shape for the core; (2) Shell growth stage: Under a protective atmosphere, the Ni unit salt solution is switched to a Ni / Zr / Al ternary salt solution, and a second complexing agent solution, a precipitant solution, and an additive are continuously added to form a shell structure with a (101) orientation growth. After reaching the target particle size, the reaction is stopped to obtain a precursor slurry with a core-shell orientation growth structure; (3) Post-treatment stage: The slurry is washed and dried to obtain a super-high nickel precursor with a core-shell orientation growth structure.

3. The preparation method according to claim 2, characterized in that, The first complexing agent solution includes a urea solution containing ammonia water, the ammonia water concentration is 2 wt% - 10 wt%, and the urea concentration is 0.2 mol / L - 2 mol / L; the second complexing agent solution includes ammonia water, urea, and an additive, and the additive is an organic acid capable of enhancing the complexation of Zr / Al ions, including at least one of citric acid, oxalic acid, or ethylenediaminetetraacetic acid, where the ammonia water concentration is 2 wt% - 10 wt%, the urea concentration is 0.2 mol / L - 2 mol / L, and the additive concentration is 0.1 wt% - 3 wt%.

4. The preparation method according to claim 2, characterized in that, The pH, ammonia concentration, and temperature in the shell growth stage in step (2) are all higher than those in the core growth stage in step (1), while the stirring speed is lower than that in the core growth stage in step (1); preferably, the pH in the core growth stage in step (1) is 9 - 10.5, the ammonia concentration is 0.5 g / L - 2 g / L, the temperature is 40 - 60 °C, and the stirring speed is 400 rpm - 600 rpm; preferably, the pH in the shell growth stage in step (2) is 10 - 11, the ammonia concentration is 2 g / L - 4 g / L, the temperature is 50 - 70 °C, and the stirring speed is 200 rpm - 400 rpm; preferably, the gas used in the protective atmosphere in steps (1) and (2) includes nitrogen and / or other inert gases.

5. The preparation method according to claim 2, characterized in that, The metal salt in the Ni unit salt solution in step (1) includes at least one of nickel sulfate, nickel nitrate, or nickel halide; preferably, the total metal ion concentration in the Ni unit salt solution in step (1) is 1 mol / L - 3 mol / L.

6. The preparation method according to claim 2, characterized in that, The precipitant in the precipitant solution in step (1) includes at least one of sodium hydroxide, potassium hydroxide, lithium hydroxide, or sodium carbonate; preferably, the precipitant concentration in the precipitant solution in step (1) is 10 wt% - 40 wt%.

7. The preparation method according to claim 2, characterized in that, The pH value of the bottom liquid in step (1) is 9 - 10.5, and the ammonia concentration is 0.5 g / L - 2 g / L.

8. The preparation method according to claim 2, wherein The post-treatment in step (3) includes washing and drying in sequence; preferably, the drying temperature is 80 °C - 150 °C; preferably, the end point of drying is that the water content reaches below 0.8 wt%.

9. A lithium nickelate cathode material, characterized in that, The preparation raw material of the positive electrode material includes the high-rate super-high nickel precursor material described in claim 1 or 2.

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