A high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide and a preparation method thereof

Abstract

The present invention relates to a high nickel ternary positive electrode material modified with a boron zirconium compound and an amorphous aluminum oxide and a preparation method thereof, belonging to the technical field of positive electrode materials. The problem of high residual alkali content on the surface of high nickel ternary positive electrode materials in the prior art is solved. The high nickel ternary positive electrode material of the present invention has the general chemical formula LiNi x Co y Mn z B a Zr b Al c PO2, where 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30, and x+y+z+a+b+c=1. The present invention also provides a method for preparing the high-nickel ternary positive electrode material. The preparation method of the present invention does not require the addition of related equipment, saves water resources, avoids the consumption of lithium resources, is safe and environmentally friendly, improves resource utilization, and reduces cost. The prepared high-nickel ternary positive electrode material has high structure and thermal stability, and has comprehensive excellent performance such as high gram-to-gram capacity, low DCIR growth, long cycle life, and high-temperature storage.

Description

Technical Field

[0001] The present invention belongs to the technical field of positive electrode materials, and in particular relates to a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide, and a preparation method thereof. Background Art

[0002] Lithium-ion batteries are secondary batteries (rechargeable batteries) that rely primarily on the movement of lithium ions between positive and negative electrodes. Amidst the growing global energy crisis and environmental pollution, lithium-ion batteries are attracting significant attention as a new type of green energy storage device. They are widely used in 3C digital devices, wearables, power tools, and new energy vehicles. With the rapid development of new energy vehicles, demand for lithium-ion batteries has increased dramatically, driving a growing demand for batteries with high energy density, low cost, and excellent value for money.

[0003] Ternary NCM, NCA, and NCMA cathode materials are widely used in lithium-ion batteries as high-energy-density cathode materials. Co, a rare metal with much lower proven reserves than Ni, Mn, and Al, exhibits a certain degree of radioactivity. High specific capacity, high energy density, and long driving range are the main themes and user demands of current new energy vehicles. However, increasing Ni content leads to a decrease in the material's DSC thermal decomposition temperature, an increase in heat release, and poor thermal stability. Furthermore, increased Ni content makes the material surface more susceptible to reaction with CO2 and H2O in the environment, generating LiOH and Li2CO3 on the surface. LiOH reacts with LiPF6 in the electrolyte to generate HF, which corrodes Ni and Mn and causes the surface coating to dissolve, shortening the cycle and storage life. During high-voltage polarization during charging or high-temperature storage, Li2CO3 reacts and decomposes to produce CO2, CH4, and other substances. Finally, increasing nickel content leads to severe Li / Ni mixing, resulting in poor cycle and storage life.

[0004] In order to further improve the cycle and storage life of high nickel ternary positive electrode materials, reduce Li / Ni mixing, and reduce the surface residual alkali of high nickel ternary positive electrode materials, it is particularly important. In the existing technology, water washing (wet method) is usually used to reduce the residual alkali content on the surface of high nickel ternary positive electrode materials. Although the water washing method can effectively reduce the residual alkali on the surface of high nickel ternary positive electrode materials, the gram-to-gram capacity of high nickel ternary positive electrode materials will be reduced, and the cycle performance will be reduced. Because high nickel ternary positive electrode materials are sensitive to water, the Li on the surface of the material will be reduced during the long-term water washing process. +It is easy to dissolve, and there may be a replacement process during the dissolution. Water molecules may slowly enter the grain boundary area of the electrode material particles, resulting in the inability to fully escape the water during the later drying, thereby affecting the electrochemical performance of the material. In addition, based on materials with Ni ≥ 80, the water-to-material ratio of the water washing process is 1:1 or above, and the consumption ratio of pure water is ≥ 1. The investment cost of related pure water preparation, water washing filter press drying equipment, and wastewater purification equipment increases the cost per ton of raw materials, and the process time increases by 40% year-on-year. In addition, the recovery rate of Li in the water washing process is low, the difficulty is high, and the investment is high. Researchers have found that in addition to the commonly used cationic metal modification, the use of boron compounds such as boron oxide or boric acid, or boron-doped compounds as a coating layer can isolate the electrolyte, which is beneficial to improving the cycle performance of the positive electrode material. For example, a Chinese patent for a high-capacity nickel-cobalt-manganese-oxide-based composite positive electrode material and its preparation method (publication number CN108899502A) is a method for coating boron on the surface of the positive electrode material through a second calcination after washing with water. This can improve the surface structure of the material, improve the interface stability, and thus improve the cycle performance. However, boron coating on the surface of the material cannot avoid the generation of microcracks and particle breakage during high-temperature storage and cycling. Particle breakage will aggravate the gas production of lithium-ion batteries, and gas production will cause flatulence in soft-pack lithium-ion batteries; the bubbles generated accumulate inside the battery cell and also cause lithium precipitation at the edge of the bubbles. Therefore, a single type of element cannot significantly improve the performance of the material, so composite doping and gradient coating are currently one of the effective measures.

[0005] In the prior art, Yu Chunlin et al. provided a B element doping method for preparing a ternary precursor and a subsequent preparation method in their Chinese patent Boron element doped high nickel ternary precursor material, its preparation method and high nickel ternary positive electrode material (publication number CN114988494A). The high nickel ternary precursor material has the molecular formula: Ni a Co b Mn c (OH)2·(BO2) d; wherein, 0.8 ≤ a < 1, 0 < b ≤ 0.15, 0 < c ≤ 0.05, and a + b + c = 1; 0 < d ≤ 0.05; the core of the high-nickel ternary precursor material has a dense packing structure, the shell is a loose structure with dendritic radiation, and the high-nickel ternary precursor core-shell has uniform doping of element B. In this solution, doping elements are added during the preparation process of the above precursor material to ensure the uniformity of the doping elements, and the obtained precursor material has good high-temperature stability and can obtain a full-radial cathode material with excellent performance through high-temperature sintering. Another example is the zirconium and polyanion co-doped ternary precursor solution and subsequent preparation method provided by Zhang Bao et al. in the Chinese patent "Ternary Cathode Material Precursor Doped with Zirconium and Polyanions, Its Preparation Method, and Ternary Cathode Material" (CN113764647A); this method provides a zirconium and polyanion co-doped ternary cathode material precursor, including a ternary cathode material precursor body and a zirconia modification layer on the surface of the precursor body, and Zr elements and polyanion elements are uniformly distributed in the bulk structure of the precursor particles. The doping elements of this cathode material are evenly distributed, the structure stability of the cathode material is good, the Li + transport barrier is low, the electrochemical performance is good, and the preparation method has a short process flow, prominent social benefits, and is suitable for popularization and application. He Liper et al. provided a Zr-doped ternary precursor solution and subsequent preparation method in the Chinese patent "Nickel Cobalt Manganese Ternary Material Doped with Zirconium and Its Preparation Method" (CN109659555A), which mainly includes the following steps: including: after treating the positive electrode sheet obtained by disassembling and retiring lithium-ion batteries, obtaining a leaching solution containing Li + , Ni 2+ , Co 2+ , Mn 2+ and Zr 2+ ; adjusting the contents of nickel, cobalt, manganese and zirconium elements in the leaching solution to obtain a raw material solution for synthesizing a Zr-doped nickel cobalt manganese ternary precursor; using the raw material solution to synthesize a Zr-doped ternary material precursor and a lithium-containing solution; concentrating the lithium-containing solution by a certain multiple and then recovering the lithium salt therein by a precipitation method; preheating the Zr-doped nickel cobalt manganese ternary precursor at a high temperature to obtain a Zr-doped ternary material intermediate; mixing the intermediate with the lithium salt evenly and then obtaining a Zr-doped nickel cobalt manganese ternary material through a high-temperature solid-phase reaction. This preparation method realizes the recycling of nickel, cobalt, manganese and zirconium elements in retired lithium-ion batteries and simultaneously improves the electrochemical performance of nickel cobalt manganese ternary materials. The above several methods use B or Zr element salt compounds to react at the precursor end to prepare the precursor, which increases the difficulty of precursor reaction synthesis to a certain extent and increases the difficulty of later reactions of impurity elements; at the same time, they belong to single-type elements and the effects shown are not prominent; later, similar elements still need to be added at the ternary preparation end to further modify the performance of high-nickel ternary cathode materials, resulting in problems such as high preparation costs of front-end materials. SUMMARY OF THE INVENTION

[0006] One of the purposes of the present invention is to provide a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide, which has comprehensive excellent properties such as long cycle life, high high-temperature rate, high gram-specific capacity, and low DCIR growth.

[0007] The second object of the present invention is to provide a method for preparing a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide. This method solves the problem of high residual alkali content on the surface of the high-nickel ternary positive electrode material in the prior art without adding related equipment. At the same time, it saves water resources and avoids water resource pollution, environmental pollution and lithium resource consumption caused by the precipitation of metal elements during water washing, thereby further improving resource utilization and reducing cost consumption.

[0008] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are as follows.

[0009] The present invention provides a high nickel ternary positive electrode material modified by a boron zirconium compound and an amorphous aluminum oxide. The chemical formula of the high nickel ternary positive electrode material is LiNi x Co y Mn z B a Zr b Al c PO2, where 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30, and x+y+z+a+b+c=1;

[0010] The present invention also provides a method for preparing the high-nickel ternary positive electrode material modified with the boron-zirconium compound and amorphous aluminum oxide, comprising the following steps:

[0011] Step 1: After uniformly mixing the high-nickel ternary precursor, lithium source, and doping compound, sintering is performed in an oxygen or oxygen-air atmosphere, cooling, crushing, screening, and demagnetizing to obtain a high-nickel ternary positive electrode material substrate;

[0012] The chemical formula of the high nickel ternary precursor is Ni x Co y Mn z (OH)2, where 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30 and x+y+z=1;

[0013] The doping compound is ZrB2 and amorphous Al2O3, ZrB2 is a hexagonal crystal with a purity of ≥99%, and the amorphous Al2O3 is one or more of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3. The high nickel ternary precursor and the lithium source are Li +The molar ratio of the total doping elements in the doping compound is 1: (0.96 ~ 1.10): (0.0001 ~ 0.01), and the mass ratio of the high nickel ternary precursor to ZrB2 is 100:

[0014] (0.05~0.60), the mass ratio of high nickel ternary precursor to amorphous Al2O3 is 100:(0.10~0.50);

[0015] The primary sintering conditions are as follows: heating to 400-460° C. and holding for 2-6 hours at a heating rate of 1-5° C. / min, heating to 580-740° C. and holding for 2-5 hours at a second stage, and heating to 740-970° C. and holding for 6-24 hours at a third stage; or heating to 400-460° C. and holding for 2-6 hours at a heating rate of 1-30° C. / h, heating to 580-740° C. and holding for 2-5 hours at a second stage, and heating to 740-970° C. and holding for 6-24 hours at a third stage;

[0016] Step 2: washing the high nickel ternary positive electrode material substrate prepared in step 1 with water, and drying it to obtain a washed and dried high nickel ternary positive electrode material substrate;

[0017] Step 3: Evenly mix the washed and dried high-nickel ternary cathode material substrate, ZrB2 and amorphous Al2O3, perform secondary calcination in an oxygen or oxygen-air atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined high-nickel ternary cathode material substrate;

[0018] The ZrB2 is a hexagonal crystal with a purity of ≥99%, the amorphous Al2O3 is one or more of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3, the mass ratio of the washed and dried high-nickel ternary positive electrode material substrate to ZrB2 is 100:(0.05-0.30), and the mass ratio of the washed and dried high-nickel ternary positive electrode material substrate to the amorphous Al2O3 is 100:(0.08-0.25);

[0019] The secondary calcination conditions are: heating to 350-720°C at a heating rate of 1-20°C / H and keeping the temperature for 1-24h;

[0020] Step 4: The secondary calcined high nickel ternary positive electrode material substrate and LiPO3 are mixed and coated in a mass ratio of 100: (0.2-1.3), and the obtained coated product is calcined three times in an oxygen or oxygen-air atmosphere, cooled, crushed, sieved, and demagnetized to obtain a thrice-calcined high nickel ternary positive electrode material substrate;

[0021] The conditions for the three calcinations are: heating to 200-400°C at a heating rate of 1-20°C / H and keeping the temperature for 1-10 hours;

[0022] Step 5: batch-mixing the thrice-calcined high-nickel ternary cathode material substrate at low temperature under dehydrated and decarbonated gas or inert atmosphere to obtain a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide;

[0023] The low-temperature batch mixing conditions are: heating the temperature to 100-200° C. at a heating rate of 1-5° C. / min, mixing the materials for 0.5-6 hours, and replacing the materials every 0.5-1.0 hour.

[0024] Preferably, in step 1, the high nickel ternary precursor and the lithium source are + , the molar ratio of the total doping elements in the doping compound is 1: (0.98 ~ 1.08): (0.0003 ~ 0.008), the mass ratio of the high nickel ternary positive electrode material precursor to ZrB2 is 100: (0.1 ~ 0.45), and the mass ratio of the high nickel ternary positive electrode material precursor to amorphous Al2O3 is 100: (0.15 ~ 0.40); more preferably, the high nickel ternary precursor, the lithium source Li + , the molar ratio of the total doping elements in the doping compound is 1:(0.99~1.05):(0.0012~0.0060), the mass ratio of the high nickel ternary positive electrode material precursor to ZrB2 is 100:(0.18~0.40), and the mass ratio of the high nickel ternary positive electrode material precursor to amorphous Al2O3 is 100:(0.20~0.38).

[0025] Preferably, in step 1 and step 3, the ZrB2 is a hexagonal crystal with a purity of ≥99% and a particle size of 1 to 15 μm; more preferably, the particle size is 2 to 4 μm.

[0026] More preferably, the preparation is carried out by the following method: uniformly mixing metallic zirconium, boron carbide and boron nitride, heating and firing under an inert atmosphere to obtain a ZrB2 block with a purity ≥99% and a hexagonal crystal form, decarburizing, cooling and crushing to obtain ZrB2.

[0027] Particularly preferably, the inert atmosphere is argon or hydrogen, the heating and firing temperature is 2000° C., the time is 4 to 8 hours, and the decarburization process is: in an oxidizing atmosphere, keeping warm at 350° C. for 12 hours.

[0028] Preferably, in step 1, the high-nickel ternary precursor is a small-particle high-nickel ternary precursor or a large-particle high-nickel ternary precursor, the particle size of the small-particle high-nickel ternary precursor is 2 to 6 μm, and the particle size of the large-particle high-nickel ternary precursor is 7 to 15 μm; more preferably, the particle size of the small-particle high-nickel ternary precursor is 3.0 to 5.0 μm, and the particle size of the large-particle high-nickel ternary precursor is 9 to 12 μm;

[0029] More preferably, the high-nickel ternary precursor in step 1 is a large-particle high-nickel ternary precursor, the particle size of the prepared high-nickel ternary positive electrode material substrate is 8 to 16 μm, and the particle size of the prepared high-nickel ternary positive electrode material is 8 to 16 μm; particularly preferably, the particle size of the prepared high-nickel ternary positive electrode material substrate is 9 to 12 μm, and the particle size of the prepared high-nickel ternary positive electrode material is 9 to 12 μm;

[0030] More preferably, the high-nickel ternary precursor in step one is a small-particle high-nickel ternary precursor, the particle size of the prepared high-nickel ternary positive electrode material substrate is 2.5-6.0 μm, and the particle size of the prepared high-nickel ternary positive electrode material is 2.5-6.0 μm; particularly preferably, the particle size of the prepared high-nickel ternary positive electrode material substrate is 3.0-5.0 μm, and the particle size of the prepared high-nickel ternary positive electrode material is 3.0-5.0 μm; most preferably, the particle size of the prepared high-nickel ternary positive electrode material is 3.5-4.5 μm.

[0031] Preferably, in step 1, the lithium source is one or more of LiOH, LiOH·H2O, Li2CO3 and LiNO3; more preferably, the lithium source is one or two of LiOH·H2O and Li2CO3.

[0032] Preferably, in step 1, the particle size of the lithium source is 4 to 10 μm.

[0033] Preferably, in steps one and three, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (0-80): (0-80): (0-80): (0-10); more preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (10-60): (10-60): (5-70): (2-8), and particularly preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (20-50): (20-50): (20-70): (3-6).

[0034] Preferably, in step 1, the equipment used for uniform mixing is a ball mill, a pot mill, a plowshare mixer or a high-speed mixer; more preferably, the equipment used for uniform mixing is a ball mill, a plowshare mixer or a high-speed mixer.

[0035] Preferably, in step one, the equipment used for the primary sintering is a muffle furnace or a tubular furnace, and the conditions for the primary sintering are: at a heating rate of 2 to 4°C / min, the first stage is heated to 420 to 460°C and kept warm for 3 to 5 hours, the second stage is heated to 620 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 8 to 20 hours; more preferably, at a heating rate of 3°C / min, the first stage is heated to 420 to 460°C and kept warm for 4 hours, the second stage is heated to 640 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 10 to 18 hours.

[0036] Preferably, in step one, the equipment used for the primary sintering is an atmosphere roller kiln or a rotary kiln, and the conditions for the primary sintering are: at a heating rate of 5 to 20°C / h, the first stage is heated to 420 to 460°C and kept warm for 3 to 5 hours, the second stage is heated to 620 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 8 to 20 hours; more preferably, at a heating rate of 10°C / h, the first stage is heated to 420 to 460°C and kept warm for 4 hours, the second stage is heated to 640 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 10 to 18 hours.

[0037] Preferably, in step 1 and step 3, the oxygen concentration is ≥ 95%.

[0038] Preferably, in step 2, the water washing conditions are: the mass ratio of material to water is 1: (0.5-3.0), the time is 10-120s, and the filter press pre-dehydration is performed during the water washing process. After the pre-dehydration, nitrogen is introduced for purging for 1-4 hours, and the moisture content of the filter cake is controlled to be ≤7%; more preferably, the mass ratio of material to water is 1: (1.0-2.0), the time is 20-60s, and the nitrogen is purged for 2-3 hours; especially preferably, the mass ratio of material to water is 1: 1.5, and the time is 30s.

[0039] Preferably, in step 2, the drying temperature is 120-200°C and the drying time is 1-12 hours; more preferably, the drying temperature is 130-180°C and the drying time is 3-10 hours; particularly preferably, the drying temperature is 150-160°C and the drying time is 4-8 hours.

[0040] Preferably, in the step three, the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to ZrB2 is 100: (0.10-0.25), and the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to amorphous Al2O3 is 100: (0.10-0.22); more preferably, the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to ZrB2 is 100: (0.12-0.20), and the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to amorphous Al2O3 is 100: (0.12-0.20).

[0041] Preferably, in the step three, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (0~80):(0~80):(0~80):(0~10); more preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (10~60):(10~60):(5~70):(2~8), and particularly preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (20~50):(20~50):(20~70):(3~6).

[0042] Preferably, in step three, the secondary calcination conditions are: heating to 400-680°C at a heating rate of 1-20°C / H and keeping warm for 3-14 hours; more preferably, heating to 420-580°C at a heating rate of 1-20°C / H and keeping warm for 6-11 hours.

[0043] Preferably, in step 3, the equipment for uniform mixing is a high-speed mixer or a mechanical fusion machine; more preferably, the equipment for uniform mixing is a high-speed mixer.

[0044] Preferably, in step four, the mass ratio of the secondary calcined high nickel ternary positive electrode material substrate to LiPO3 is 100: (0.3 to 1.0); more preferably, the mass ratio of the secondary calcined high nickel ternary positive electrode material substrate to LiPO3 is 100: (0.4 to 0.8).

[0045] Preferably, in step 4, the conditions for the three calcinations are: heating to 240-385°C at a heating rate of 1-20°C / H and keeping warm for 3-8 hours; more preferably, heating to 300-380°C at a heating rate of 1-20°C / H and keeping warm for 4-7 hours.

[0046] Preferably, in the step five, the low-temperature batch mixing conditions are: heating to 120-180°C at a heating rate of 1-4°C / min, mixing for 2.0-5.0h, and replacing once every 0.5-1.0h; more preferably, heating to 140-160°C at a heating rate of 2-3°C / min, mixing for 3.0-4.0h, and replacing once every 0.5-1.0h.

[0047] The principle of the preparation method of the high-nickel ternary positive electrode material modified with boron-zirconium compound and amorphous aluminum oxide of the present invention is as follows:

[0048] First, by utilizing the hexagonal crystal structure and DSC stability characteristics of ZrB2, and the comprehensive characteristics of amorphous Al2O3 atoms and ionic crystals, B / Zr / Al are co-doped through a high-temperature solid-phase reaction to improve the structure and thermal stability of the nickel-cobalt-manganese ternary cathode material, reduce microcracks in the high-nickel material structure; widen the ion channel and interlayer distance, improve the material's discharge efficiency and rate capability; and reduce the degree of Li / Ni mixing and the particle surface energy.

[0049] Second, by optimizing the lithium ratio and doping element formula system and adopting a three-stage single-firing process mode, the degree of Li / Ni mixing of high-nickel ternary cathode materials is reduced, the radial growth of particles is optimized, and the DCIR is reduced;

[0050] Third, the residual alkali on the particle surface is reduced by washing with deionized water, thereby reducing the surface alkali content;

[0051] Fourth, by mixing ZrB2 and amorphous Al2O3 with the obtained Ni / Co / Mn / B / Zr / Al oxide matrix and then calcining it twice to form a B / Zr / Al coating, the contact between the positive electrode material and the electrolyte is reduced, and residual alkali such as Li2CO3 on the surface of the material is eliminated, thereby inhibiting the occurrence of interfacial side reactions; improving the surface electronic conductivity and the first discharge efficiency; and improving the structure and cycle stability of the material;

[0052] Fifth, by introducing LiPO3 secondary coating and three low-temperature calcination processes, a gradient coating is formed to block moisture reaction, reduce surface residual alkali, repair the surface characteristics of the particles, further improve the surface conductivity, reduce the surface waterproof barrier ability, form a surface coating protective layer, further improve surface side reactions, and improve cycle performance;

[0053] Sixth, low-temperature batch mixing can further remove moisture absorbed by surface particles during the process, inhibit the reaction of residual alkali on the surface, and reduce the loss of drying materials and irreversible reactions in the later stage.

[0054] Compared with the prior art, the present invention has the following beneficial effects:

[0055] The present invention's method for preparing a high-nickel ternary cathode material modified with a boron-zirconium compound and amorphous aluminum oxide eliminates the need for additional equipment, conserves water resources, avoids the consumption of lithium resources, is safe and environmentally friendly, improves resource utilization, and reduces costs. Furthermore, the prepared high-nickel ternary cathode material modified with a boron-zirconium compound and amorphous aluminum oxide exhibits high structural and thermal stability, and possesses comprehensive excellent properties such as high gram-to-gram capacity, low DCIR growth, long cycle life, and high-temperature storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the examples of the present invention, the following briefly introduces the drawings required for use in the examples. Obviously, the drawings described below are only some examples of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0057] Figure 1 The cycle curves of the high nickel ternary positive electrode materials of Examples 1 and 2 of the present invention and Comparative Examples 1 and 2 are shown;

[0058] Figure 2 The cycle curves of the high nickel ternary positive electrode materials of Examples 3-4 and Comparative Examples 3-4 of the present invention are shown;

[0059] Figure 3 The cycle curves of the high nickel ternary positive electrode materials of Examples 5-6 of the present invention and Comparative Examples 5-6 are shown;

[0060] Figure 4 The SEM morphology characteristics of the high nickel ternary cathode materials of Examples 1 to 6 of the present invention;

[0061] Figure 5 The full battery cycle curves of high nickel ternary battery of Example 1 of the present invention and Comparative Example 1 are shown;

[0062] Figure 6 The present invention provides a simplified process flow chart for the preparation of a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide. DETAILED DESCRIPTION

[0063] In order to further understand the present invention, preferred embodiments of the present invention are described below. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the present invention.

[0064] The boron zirconium compound and the amorphous aluminum oxide modified high nickel ternary positive electrode material of the present invention have the chemical formula of LiNi x Co y Mn z B a Zr b Al c PO2, where 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30, and x+y+z+a+b+c=1.

[0065] like Figure 6 As shown, the preparation method of the high-nickel ternary positive electrode material modified by the boron zirconium compound and the amorphous aluminum oxide of the present invention comprises the following steps:

[0066] Step 1: After uniformly mixing a high-nickel ternary precursor, a lithium source (usually a lithium salt) and a doping compound (ZrB2 and amorphous Al2O3, i.e., additive 1), sintering is performed in an oxygen or oxygen-air atmosphere, followed by cooling, crushing (coarse and fine crushing), sieving, and demagnetizing to obtain a high-nickel ternary positive electrode material substrate;

[0067] Step 2: washing the high nickel ternary positive electrode material substrate prepared in step 1 with water, and drying it to obtain a washed and dried high nickel ternary positive electrode material substrate;

[0068] Step 3: Evenly mix the washed and dried high-nickel ternary cathode material substrate, ZrB2 and amorphous Al2O3, perform secondary calcination in an oxygen or oxygen-air atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined high-nickel ternary cathode material substrate;

[0069] Step 4: The secondary calcined high nickel ternary positive electrode material substrate and LiPO3 are mixed and coated in a mass ratio of 100: (0.2-1.3), and the obtained coated product is calcined three times in an oxygen or oxygen-air atmosphere, cooled, crushed, sieved, and demagnetized to obtain a thrice calcined high nickel ternary positive electrode material substrate;

[0070] Step 5: The thrice-calcined high-nickel ternary positive electrode material substrate is batch-mixed at low temperature under dehydrated and decarbonated gas or inert atmosphere to obtain a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide.

[0071] It should be noted that in step 1, the chemical formula of the high nickel ternary precursor is Ni x Co y Mn z (OH)2, wherein 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30, and x+y+z=1. The high nickel ternary precursor is a small-particle high nickel ternary precursor or a large-particle high nickel ternary precursor, or a mixture of the two. The particle size of the small-particle high nickel ternary precursor is 2-6 μm, and the particle size of the large-particle high nickel ternary precursor is 7-15 μm. Preferably, the particle size of the small-particle high nickel ternary precursor is 3.0-5.0 μm, and the particle size of the large-particle high nickel ternary precursor is 9-12 μm.

[0072] It should be noted that in step 1, the lithium source is preferably one or more of LiOH, LiOH·H2O, Li2CO3, and LiNO3; more preferably one or two of LiOH·H2O and Li2CO3. The lithium source has a particle size of 4 to 10 μm and can typically be obtained by mechanically grinding coarse lithium source particles or selecting a commercial lithium source of similar specifications.

[0073] It should be noted that in step 1, amorphous Al2O3 is one or more of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3; preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (0-80): (0-80): (0-10); more preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (10-60): (10-60): (5-70): (2-8), and particularly preferably, the mass ratio of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 is (20-50): (20-50): (20-70): (3-6).

[0074] It should be noted that in step one, the purity of ZrB2 is ≥99%, and it is a hexagonal crystal with a particle size of 1 to 15 μm. ZrB2 can be prepared by the following method, but is not limited thereto, and can also be obtained commercially. Metal zirconium, boron carbide and boron nitride are mixed evenly, heated and fired under an inert atmosphere to obtain a hexagonal crystal ZrB2 block with a purity of ≥99%, decarburized, cooled, and crushed to 1 to 15 μm to obtain ZrB2; preferably, the inert atmosphere is argon or hydrogen, the heating and firing temperature is 2000°C, the time is 4 to 8 hours, and the decarburization process is: in an oxidizing atmosphere, keep warm at 350°C for 12 hours; the equipment commonly used for crushing is a grinder. Reaction formula: 3ZrO2+B4C+8C+B2O3=3ZrB2+9CO↑.

[0075] It should be noted that in step 1, the high nickel ternary precursor and the Li + , the molar ratio of the total doping elements (Zr, B and Al) in the doping compound is 1: (0.96~1.10): (0.0001~0.01), preferably 1: (0.98~1.08): (0.0003~0.008), and more preferably 1: (0.99~1.05): (0.0012~0.0060); the mass ratio of the high nickel ternary positive electrode material precursor to ZrB2 is 100: (0.05~0.60), preferably 100: (0.1~0.45), and more preferably 100: (0.15~0.40); the mass ratio of the high nickel ternary positive electrode material precursor to amorphous Al2O3 is 100: (0.10~0.50), preferably 100: (0.15~0.40), and more preferably 100: (0.20~0.38).

[0076] It should be noted that, in step 1, the equipment used for uniform mixing is a mixing equipment such as a ball mill, a pot mill, a plowshare mixer, a high-speed mixer, etc.; preferably, a ball mill, a plowshare mixer, and a high-speed mixer.

[0077] It should be noted that, in step 1, the oxygen concentration is preferably ≥ 95%.

[0078] It should be noted that in step 1, there are usually two modes for one sintering:

[0079] The equipment used in the one-shot sintering mode is a muffle furnace or a tubular furnace, with a heating rate of 1 to 5°C / min, the first stage is heated to 400 to 460°C and kept warm for 2 to 6 hours, the second stage is heated to 580 to 740°C and kept warm for 2 to 5 hours, and the third stage is heated to 740 to 970°C and kept warm for 6 to 24 hours; preferably, the first stage is heated to 420 to 460°C and kept warm for 3 to 5 hours, the second stage is heated to 620 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 8 to 20 hours at a heating rate of 2 to 4°C / min; more preferably, the first stage is heated to 420 to 460°C and kept warm for 4 hours, the second stage is heated to 640 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 10 to 18 hours at a heating rate of 3°C / min;

[0080] Another type of equipment used for primary sintering is an atmosphere roller kiln or a rotary kiln, with a heating rate of 1 to 30°C / h, the first stage is heated to 400 to 460°C and kept warm for 2 to 6 hours, the second stage is heated to 580 to 740°C and kept warm for 2 to 5 hours, and the third stage is heated to 740 to 970°C and kept warm for 6 to 24 hours; preferably, the first stage is heated to 420 to 460°C and kept warm for 3 to 5 hours, the second stage is heated to 620 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 8 to 20 hours at a heating rate of 5 to 20°C / h; more preferably, the first stage is heated to 420 to 460°C and kept warm for 4 hours, the second stage is heated to 640 to 740°C and kept warm for 3 to 4 hours, and the third stage is heated to 740 to 970°C and kept warm for 10 to 18 hours at a heating rate of 10°C / h.

[0081] It should be noted that in step one, the high-nickel ternary precursor is a large-particle high-nickel ternary precursor, and the particle size of the prepared high-nickel ternary positive electrode material substrate is 8 to 16 μm, preferably 9 to 12 μm, and the particle size of the high-nickel ternary positive electrode material is 8 to 16 μm, preferably 9 to 12 μm; when the high-nickel ternary precursor is a small-particle high-nickel ternary precursor, the particle size of the prepared high-nickel ternary positive electrode material substrate is 2.5 to 6.0 μm, preferably 3.0 to 5.0 μm, and the particle size of the high-nickel ternary positive electrode material is 2.5 to 6.0 μm, preferably 3.0 to 5.0 μm; more preferably 3.5 to 4.5 μm.

[0082] It should be noted that in step 2, the equipment used for water washing is usually a disperser. The preferred water washing conditions are: material: water = 1: 0.5 ~ 3.0, time 10 ~ 120s, and the water washing process is gradually injected into a plate and frame filter press for pressure filtration pre-dehydration. After the pre-dehydration, nitrogen is introduced for purging for 1 ~ 4H, and the moisture content of the filter cake is controlled to be ≤7%; more preferably, material: water = 1: 1.0 ~ 2.0, time 20 ~ 60s, and nitrogen is purged for 2 ~ 3H; especially preferably, material: water = 1: 1.5, time 30s.

[0083] It should be noted that, in step 2, the drying equipment is usually a vacuum oven or a double cone dryer, and the preferred drying temperature is 120-200°C and the drying time is 1-12 hours; more preferably, the drying temperature is 130-180°C and the drying time is 3-10 hours; especially preferably, the drying temperature is 150-160°C and the drying time is 4-8 hours.

[0084] It should be noted that in step three, the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to ZrB2 is 100: (0.05~0.30), preferably 100: (0.1~0.25), and more preferably 100: (0.12~0.20); the mass ratio of the washed and dried high nickel ternary positive electrode material substrate to amorphous Al2O3 is 100: (0.08~0.25), preferably 100: (0.1~0.22), and more preferably 100: (0.12~0.20).

[0085] It should be noted that in step 3, the ZrB2 and amorphous Al2O3 are subject to the relevant limitations in step 1 and will not be repeated here. The limitations in steps 1 and 3 are independent limitations, that is, the ZrB2 and amorphous Al2O3 in steps 1 and 3 can be different.

[0086] It should be noted that, in step 3, the equipment for uniform mixing is usually a high-speed mixer or a mechanical fusion machine, preferably a high-speed mixer.

[0087] It should be noted that, in step 3, the oxygen concentration is preferably ≥ 95%.

[0088] It should be noted that in step three, the conditions for the secondary calcination are: heating to 350-720°C at a heating rate of 1-20°C / H and keeping warm for 1-24h; preferably, heating to 400-680°C at a heating rate of 1-20°C / H, and keeping warm for 3-14h; more preferably, heating to 420-580°C at a heating rate of 1-20°C / H, and keeping warm for 6-11h.

[0089] It should be noted that in step 4, the mass ratio of the secondary calcined high-nickel ternary positive electrode material substrate to LiPO3 is preferably 100: (0.3~1.0); more preferably 100: (0.4~0.8).

[0090] It should be noted that in step 4, the conditions for the three calcinations are: heating to 200-400°C at a heating rate of 1-20°C / H and keeping warm for 1-10 hours; preferably, heating to 240-385°C at a heating rate of 1-20°C / H and keeping warm for 3-8 hours; more preferably, heating to 300-380°C at a heating rate of 1-20°C / H and keeping warm for 4-7 hours.

[0091] It should be noted that, in step 4, the oxygen concentration is preferably ≥ 95%.

[0092] It should be noted that in step 5, the low-temperature batch mixing is heated to 100-200°C at a rate of 1-5°C / min. The tank body and mold temperature controller are combined to increase the temperature and mix at the set temperature for 0.5-6 hours. The exhaust is replaced every 0.5 hours. The main purpose is to remove moisture from the surface of the particles and repair the particle surface. After completion, vacuum packaging is performed. Preferably, the low-temperature batch mixing is heated to 120-180°C at a rate of 1-4°C / min and mixed for 2.0-5.0 hours, replaced every 0.5 hours; preferably, the temperature is heated to 140-160°C at a rate of 2-3°C / min and mixed for 3.0-4.0 hours, replaced every 0.5 hours.

[0093] It should be noted that, in step five, the crushing equipment is usually a colloid mill, and the low-temperature batch mixing is usually carried out in a batch mixing tank, and dry gas (dehydrated and decarbonated gas) is introduced for protection.

[0094] The terms used in the present invention generally have the meanings commonly understood by those skilled in the art, unless otherwise specified. In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to examples.

[0095] In the following examples, various processes and methods not described in detail are conventional methods known in the art. Unless otherwise specified, the materials, reagents, devices, instruments, equipment, etc. used in the following examples can be obtained from commercial sources.

[0096] The present invention is further described below with reference to examples.

[0097] Example 1

[0098] Step 1: Prepare Ni precursor 0.83 Co 0.11 Mn 0.06 (OH)2 (D50: 3.9 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.83 Co 0.11Mn 0.06 (OH)2 (2000g), LiOH·H2O (941.36g), ZrB2 (5.4979g), Al2O3 (3.7867g).

[0099] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 860°C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0100] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1500g sample and a coating additive (ZrB2 (2.2289g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min to mix the three powders evenly. Then, the mixture is placed in a crucible and sintered at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0101] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (5.6262 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crush, sieve, and demagnetize to obtain a thrice-calcined substrate.

[0102] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0103] Example 2

[0104] Step 1: Prepare Ni precursor 0.83 Co 0.11 Mn 0.06 (OH)2 (D50: 10.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.83 Co 0.11 Mn0.06 (OH)2 (2000g), LiOH·H2O (941.36g), ZrB2 (5.4979g), Al2O3 (3.7867g).

[0105] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat at 3 ° C / min to 460 ° C and sinter for 4.0 h in a slightly positive pressure oxygen atmosphere. Then heat to 710 ° C and sinter for 4.0 h, and then heat to 840 ° C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0106] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1600g sample and a coating additive (ZrB2 (2.3775g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min. The three powders are evenly mixed and then placed in a crucible. The mixture is sintered at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0107] Step 4: Take a 1500 g sample of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (5.6262 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0108] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0109] Example 3

[0110] Step 1: Prepare Ni precursor 0.88 Co 0.07 Mn 0.05 (OH)2 (D50: 3.9 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.88 Co 0.07 Mn 0.05(OH)2 (2000g), LiOH·H2O (941.36g), ZrB2 (5.7478g), Al2O3 (4.5440g).

[0111] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 830°C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0112] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1600g sample and a coating additive (ZrB2 (2.3775g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min to mix the three powders evenly. Then, the mixture is placed in a crucible and sintered at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0113] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (6.5639 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0114] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0115] Example 4

[0116] Step 1: Prepare Ni precursor 0.88 Co 0.07 Mn 0.05 (OH)2 (D50: 10.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.88 Co 0.07 Mn 0.05(OH)2 (2000g), LiOH·H2O (941.07g), ZrB2 (5.7478g), Al2O3 (4.5440g).

[0117] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 800°C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0118] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1600g sample and a coating additive (ZrB2 (2.3775g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min. The three powders are evenly mixed and then placed in a crucible. The mixture is sintered at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0119] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (6.5639 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0120] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0121] Example 5

[0122] Step 1: Prepare Ni precursor 0.94 Co 0.03 Mn 0.03 (OH)2 (D50: 3.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.94 Co 0.03 Mn 0.03(OH)2 (2000g), LiOH·H2O (936.76g), ZrB2 (6.2476g), Al2O3 (5.6801g).

[0123] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 800°C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0124] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1600g sample and a coating additive (ZrB2 (2.3775g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min to mix the three powders evenly. Then, the mixture is placed in a crucible and sintered at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0125] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (8.4393 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0126] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0127] Example 6

[0128] Step 1: Prepare Ni precursor 0.94 Co 0.03 Mn 0.03 (OH)2 (D50: 9.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrB2, (δ+θ+α+γ=25%+30%+40%+5%) amorphous Al2O3) raw materials, weigh Ni 0.94 Co 0.03 Mn 0.03(OH)2 (2000g), LiOH·H2O (936.76g), ZrB2 (6.2476g), Al2O3 (5.6801g).

[0129] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 760°C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0130] Step 3: Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. A 1600g sample and a coating additive (ZrB2 (2.3775g), Al2O3 (1.8176g)) are put into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min. The three powders are evenly mixed and then placed in a crucible. The mixture is sintered at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a secondary calcined substrate is obtained.

[0131] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (8.4393 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0132] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0133] Comparative Example 1

[0134] Step 1: Prepare Ni precursor 0.83 Co 0.11 Mn 0.06 (OH)2 (D50: 3.9 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.83 Co 0.11 Mn 0.06(OH)2 (2000g), LiOH·H2O (941.36g), ZrO2 (5.9494g), B2O3 (3.2234g), γ-Al2O3 (1.8158g).

[0135] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat at 3 ° C / min to 460 ° C and sinter for 4.0 h in a slightly positive pressure oxygen atmosphere. Then heat to 710 ° C and sinter for 4.0 h, and then heat to 840 ° C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0136] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a sample of 1600g and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (3.7867g)); put it into a high-speed mixer at three stages of 100rmp / 2min, 1200rpm / 30min, and 200rmp / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0137] Step 4: Take a 1500 g sample of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (5.6262 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0138] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0139] Comparative Example 2

[0140] Step 1: Prepare Ni precursor 0.83 Co 0.11 Mn 0.06 (OH)2 (D50: 10.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.83 Co 0.11 Mn0.06 (OH)2 (2000g), LiOH·H2O (941.36g), ZrO2 (5.9494g), B2O3 (3.2234g), γ-Al2O3 (3.7867g).

[0141] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat at 3 ° C / min to 460 ° C and sinter for 4.0 h in a slightly positive pressure oxygen atmosphere. Then heat to 710 ° C and sinter for 4.0 h, and then heat to 840 ° C and sinter for 11.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0142] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a 1600g sample and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (1.8158g)); put it into a high-speed mixer at three stages of 100rmp / 2min, 1200rpm / 30min, and 200rmp / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0143] Step 4: Take a 1500 g sample of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (5.6262 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0144] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0145] Comparative Example 3

[0146] Step 1: Prepare Ni precursor 0.88 Co 0.07 Mn 0.05 (OH)2 (D50: 3.9 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.88 Co 0.07Mn 0.05 (OH)2 (2000g), LiOH·H2O (941.07g), ZrO2 (6.2198g), B2O3 (3.2234g), γ-Al2O3 (4.5395g).

[0147] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 815°C and sinter for 12.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0148] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a 1600g sample and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (1.8158g)); put it into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0149] Step 4: Take a 1500 g sample of the substrate obtained in step 3 and the coating additive LiPO3 (6.5639 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a three-times calcined substrate is obtained.

[0150] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0151] Comparative Example 4

[0152] Step 1: Prepare Ni precursor 0.88 Co 0.07 Mn 0.05 (OH)2 (D50: 10.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.88 Co 0.07Mn 0.05 (OH)2 (2000g), LiOH·H2O (941.07gg), ZrO2 (6.2198g), B2O3 (3.2234g), γ-Al2O3 (4.5395g).

[0153] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 800°C and sinter for 12.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0154] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a 1600g sample and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (1.8158g)); put it into a high-speed mixer at three stages of 100rmp / 2min, 1200rpm / 30min, and 200rmp / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0155] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (6.5639 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0156] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0157] Comparative Example 5

[0158] Step 1: Prepare Ni precursor 0.94 Co 0.03 Mn 0.03 (OH)2 (D50: 3.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.94 Co0.03 Mn 0.03 (OH)2 (2000g), LiOH·H2O (936.76g), ZrO2 (6.7606g), B2O3 (3.2234g), γ-Al2O3 (5.6774g).

[0159] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 785°C and sinter for 13.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0160] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a 1600g sample and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (1.8158g)); put it into a high-speed mixer at three stages of 100 rpm / 2min, 1200 rpm / 30min, and 200 rpm / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 530°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0161] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (8.4303 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0162] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0163] Comparative Example 6

[0164] Step 1: Prepare Ni precursor 0.94 Co 0.03 Mn 0.03 (OH)2 (D50: 9.5 ± 0.5 μm), LiOH·H2O (D50: 6 ± 2 μm) and additives (ZrO2, B2O3, γ-Al2O3) as raw materials, and Ni 0.94Co 0.03 Mn 0.03 (OH)2 (2000g), LiOH·H2O (936.76g), ZrO2 (6.7606g), B2O3 (3.2234g), γ-Al2O3 (5.6774g).

[0165] Step 2: Transfer the material to a high-speed mixer and use a three-stage mixer at 200 rpm / 2 min, 800 rpm / 20 min, and 100 rpm / 3 min to mix the three powders evenly. After loading into a crucible, transfer to a muffle furnace and heat to 460°C at 3°C / min under a slightly positive pressure oxygen atmosphere and sinter for 4.0 h, then heat to 710°C and sinter for 4.0 h, and then heat to 760°C and sinter for 13.0 h; after cooling, crushing, sieving, and demagnetizing, the base material is obtained.

[0166] Step 3. Wash the substrate obtained in step 2 with water at a water-to-material ratio of 1:1.5 for 30 seconds, vacuum filter, and then dry and dehydrate in a vacuum oven at 150°C / 6h. Take a 1600g sample and coat it with additives (ZrO2 (2.5961g), B2O3 (1.5613g), γ-Al2O3 (1.8158g)); put it into a high-speed mixer at three stages of 100rmp / 2min, 1200rpm / 30min, and 200rmp / 3min to mix the three powders evenly and then put it into a crucible. Sinter at 480°C for 8.0h in an oxygen or oxygen-air (5:5) atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined substrate.

[0167] Step 4: Take a sample of 1500 g of the secondary calcined substrate obtained in step 3 and the coating additive LiPO3 (8.4303 g) and put them into a high-speed mixer according to the three-stage method of 100 rpm / 2 min, 1000 rpm / 30 min, and 200 rpm / 3 min. After the three powders are evenly mixed, they are put into a crucible and sintered at 350 ° C for 6.0 h in an oxygen or oxygen-air (5:5) atmosphere. After cooling, crushing, sieving, and demagnetization, a thrice-calcined substrate is obtained.

[0168] Step 5: Under dehydration and carbon dioxide removal, the thrice-calcined substrate obtained in step 4 was placed in a batch mixing tank at 150° C. and mixed for 3 hours. After the temperature dropped to ≤ 45° C., the substrate was unloaded, packaged, and tested for relevant physical and chemical data.

[0169] The high nickel ternary cathode materials prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were analyzed for their physical and chemical properties using scanning electron microscopes, laser particle size analyzers, Swiss Metrohm automatic titration instruments and other related equipment well known to those skilled in the art. The structures are shown in Table 1. The SEM morphology characteristics of the high nickel ternary cathode materials in Examples 1 to 6 are shown in Table 1. Figure 4 shown.

[0170] Table 1 Physical and chemical indicators of high nickel ternary positive electrode materials prepared in Examples 1 to 6 and Comparative Examples 1 to 6

[0171]

[0172] The high nickel ternary positive electrode materials prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were assembled into button batteries using a scheme for preparing positive electrode materials into lithium-ion batteries that is well known to those skilled in the art. The blue electric test system was used to measure the initial charge and discharge capacity and the 0.2C / 0.5C / 1.0C / 2.0C rate discharge performance at 25°C and 0.1C in the voltage range of 3.0 to 4.3. The results are shown in Table 2. The cycle retention rate of the above button battery was tested for 100 weeks under 1C charge and discharge conditions. The results are shown in Table 2. Figures 1 to 3 shown.

[0173] Table 2 Performance of button batteries assembled from high nickel ternary positive electrode materials prepared in Examples 1 to 6 and Comparative Examples 1 to 6

[0174]

[0175] The finished products obtained in Example 1 and Comparative Example 1 were prepared into soft-pack batteries for room temperature and high temperature cycle performance evaluation. The capacity of the batteries was maintained at more than 96% after continuous room temperature cycling for 1800 @ and at more than 92% after continuous high temperature cycling for 1200 @ under 1C / 1C-100DOD (2.75V-4.20V). Figure 5 As shown; DCIR growth is low, as shown in Table 3.

[0176] Table 3 Cyclic DCIR test data of Example 1 and Comparative Example 1

[0177]

[0178] pass Figure 1-4 As shown in Tables 1-3, the high-nickel ternary positive electrode material modified with the boron-zirconium compound and amorphous aluminum oxide prepared in the present invention has high structure and thermal stability, and has comprehensive excellent performance such as high gram-to-weight capacity, low DCIR growth, long cycle life, and high-temperature storage.

[0179] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to be limiting. Those skilled in the art will readily appreciate that other variations or modifications based on the above description are possible. It is not necessary and impossible to provide an exhaustive list of all possible embodiments. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for preparing a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide, characterized in that: The following steps are involved: Step 1: After uniformly mixing the high-nickel ternary precursor, lithium source, and doping compound, sintering is performed in an oxygen or oxygen-air atmosphere, cooling, crushing, screening, and demagnetizing to obtain a high-nickel ternary positive electrode material substrate; The chemical formula of the high nickel ternary precursor is Ni x Co y Mn z (OH)2, where 0.6≤x<1.0, 0<y≤0.30, 0<z≤0.30 and x+y+z=1; The doping compound is ZrB2 and amorphous Al2O3, ZrB2 is a hexagonal crystal with a purity of ≥99%, and the amorphous Al2O3 is one or more of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3. The high nickel ternary precursor and the lithium source are Li + , the molar ratio of the total doping elements in the doping compound is 1: (0.96~1.10): (0.0001~0.01), the mass ratio of the high nickel ternary precursor to ZrB2 is 100: (0.05~0.60), and the mass ratio of the high nickel ternary precursor to amorphous Al2O3 is 100: (0.10~0.50); The primary sintering conditions are as follows: heating to 400-460° C. and holding for 2-6 hours at a heating rate of 1-5° C. / min, heating to 580-740° C. and holding for 2-5 hours at a second stage, and heating to 740-970° C. and holding for 6-24 hours at a third stage; or heating to 400-460° C. and holding for 2-6 hours at a heating rate of 1-30° C. / h, heating to 580-740° C. and holding for 2-5 hours at a second stage, and heating to 740-970° C. and holding for 6-24 hours at a third stage; Step 2: washing the high nickel ternary positive electrode material substrate prepared in step 1 with water, and drying it to obtain a washed and dried high nickel ternary positive electrode material substrate; Step 3: Evenly mix the washed and dried high-nickel ternary cathode material substrate, ZrB2 and amorphous Al2O3, perform secondary calcination in an oxygen or oxygen-air atmosphere, cool, crush, sieve, and demagnetize to obtain a secondary calcined high-nickel ternary cathode material substrate; The ZrB2 is a hexagonal crystal with a purity of ≥99%, the amorphous Al2O3 is one or more of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3, the mass ratio of the washed and dried high-nickel ternary positive electrode material substrate to ZrB2 is 100:(0.05-0.30), and the mass ratio of the washed and dried high-nickel ternary positive electrode material substrate to the amorphous Al2O3 is 100:(0.08-0.25); The secondary calcination conditions are: heating to 350-720°C at a heating rate of 1-20°C / H and holding for 1-24 hours; Step 4: The secondary calcined high-nickel ternary positive electrode material substrate and LiPO3 are mixed and coated in a mass ratio of 100: (0.2~1.3), and the obtained coated product is calcined three times in an oxygen or oxygen-air atmosphere, cooled, crushed, sieved, and demagnetized to obtain a thrice-calcined high-nickel ternary positive electrode material substrate; The conditions for the three calcinations are: heating to 200-400°C at a heating rate of 1-20°C / H and keeping the temperature for 1-10 hours; Step 5: batch-mixing the thrice-calcined high-nickel ternary cathode material substrate at low temperature under dehydrated and decarbonated gas or inert atmosphere to obtain a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide; The low-temperature batch mixing conditions are: heating to 100-200°C at a heating rate of 1-5°C / min, mixing for 0.5-6 hours, and replacing once every 0.5-1.0 hour.

2. The method for preparing the high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step 1, the high nickel ternary precursor is a small-particle high nickel ternary precursor or a large-particle high nickel ternary precursor, the particle size of the small-particle high nickel ternary precursor is 2-6 μm, and the particle size of the large-particle high nickel ternary precursor is 7-15 μm; The high nickel ternary precursor is a large-particle high nickel ternary precursor, and the particle size of the prepared high nickel ternary positive electrode material substrate is 8~16μm, and the particle size of the prepared high nickel ternary positive electrode material is 8~16μm; The high-nickel ternary precursor is a small-particle high-nickel ternary precursor. The particle size of the prepared high-nickel ternary positive electrode material substrate is 2.5~6.0μm, and the particle size of the prepared high-nickel ternary positive electrode material is 2.5~6.0μm.

3. The method for preparing the high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step 1, The lithium source is one or more of LiOH, LiOH·H2O, Li2CO3 and LiNO3, and the particle size of the lithium source is 4~10μm.

4. The method for preparing a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the steps 1 and 3, the mass ratios of δ-Al2O3, θ-Al2O3, α-Al2O3, and γ-Al2O3 are independently (0-80): (0-80): (0-80): (0-10); The ZrB2 is prepared by the following method: metallic zirconium, boron carbide and boron nitride are uniformly mixed, heated and fired under an inert atmosphere to obtain a hexagonal ZrB2 block, decarburized, cooled, and crushed to 1-15µm to obtain ZrB2.

5. The method for preparing a high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step 1, The equipment used for the primary sintering is a muffle furnace or a tubular furnace. The primary sintering conditions are as follows: heating at a rate of 2-4°C / min, heating to 400-460°C in the first stage and holding for 3-5 hours, heating to 580-740°C in the second stage and holding for 3-4 hours, and heating to 740-970°C in the third stage and holding for 8-20 hours. Alternatively, the equipment used for the primary sintering is an atmosphere roller kiln or a rotary kiln, and the conditions for the primary sintering are: at a heating rate of 5-20°C / h, heating to 400-460°C in the first stage and keeping warm for 3-5h, heating to 580-740°C in the second stage and keeping warm for 3-4h, and heating to 740-970°C in the third stage and keeping warm for 8-20h.

6. The method for preparing a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step 2, The conditions for water washing are: the mass ratio of material to water is 1: (0.5~3.0), the time is 10~120s, and pre-dehydration is performed by filter pressing during the water washing process. After the pre-dehydration, nitrogen is introduced for purging for 1~4 hours, and the moisture content of the filter cake is controlled to be ≤7%; The drying temperature is 120~200℃ and the drying time is 1~12h.

7. The method for preparing a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step three, The mass ratio of the washed and dried high nickel ternary cathode material substrate to ZrB2 is 100:(0.05~0.30), and the mass ratio of the washed and dried high nickel ternary cathode material substrate to amorphous Al2O3 is 100:(0.08~0.25); The conditions for the secondary calcination are: heating to 400~680℃ at a heating rate of 1~20℃ / H and keeping the temperature for 3~14h.

8. The method for preparing a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In the step 4, The mass ratio of the secondary calcined high nickel ternary cathode material substrate to LiPO3 is 100:(0.3~1.3); The conditions for the three calcinations are: heating to 240~385℃ at a heating rate of 1~20℃ / H and keeping the temperature for 3~8h.

9. The method for preparing a high-nickel ternary cathode material modified with a boron-zirconium compound and an amorphous aluminum oxide according to claim 1, characterized in that: In step 5, the low-temperature batch mixing conditions are: heating to 120-180° C. at a heating rate of 1-4° C. / min and mixing for 2.0-5.0 hours, with replacement every 0.5-1.0 hour.

10. A high-nickel ternary positive electrode material modified with a boron-zirconium compound and an amorphous aluminum oxide, characterized in that: The invention is prepared by the method according to any one of claims 1 to 9.

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