A coated high-nickel material, preparation method and application

Abstract

The present invention discloses a coated high-nickel material, a preparation method thereof, and an application thereof. The coated high-nickel material includes a high-nickel material and a coating layer that wraps the surface of the high-nickel material. The coating layer is composed of a NASICON-type fast ion conductor and a metal boride. The coated high-nickel material has high surface ion / electron conductivity, is easy to dissipate heat, and has good compatibility with the electrolyte.

Description

Technical Field

[0001] The present invention relates to the technical field of cathode materials for lithium-ion batteries, and relates to a coated high-nickel material, a preparation method thereof, and an application thereof. Background Art

[0002] With the increasingly severe global warming and environmental problems, worldwide, there are requirements for the development of clean energy power generation, such as solar energy, wind energy, and hydrogen energy, to replace traditional fossil energy power generation. At the same time, in the transportation field, there are also demands for vigorously developing new energy vehicles to replace traditional fuel vehicles. Whether it is the development of clean energy power generation or the development of new energy vehicles, high-performance energy storage batteries need to be developed.

[0003] However, during the charging process, especially at high charging voltages, high-nickel materials have unstable structures, are prone to oxygen evolution, and trigger thermal runaway. At the same time, during the charging process, high-nickel materials are prone to react with the electrolyte, resulting in gas generation in the battery and a decline in battery performance.

[0004] The patent application of the invention with the publication number CN115425214A discloses a coated and modified high-nickel ternary cathode material, a preparation method thereof, and an application thereof. The preparation method includes dispersing a phosphorus source, an aluminum source, a lithium source, a titanium source, and an additive in a first solvent in sequence to obtain a coating suspension, performing first ball milling, obtaining a coating slurry, performing first drying, obtaining a lithium titanium aluminum phosphate precursor, mixing it with the high-nickel ternary cathode material after second ball milling and a second solvent, performing third ball milling, and sequentially performing second drying and sintering to obtain a coated and modified high-nickel ternary cathode material; wherein the additive is B2O3 and / or SiO2. This patent application coats a layer of lithium titanium aluminum phosphate on the surface of the high-nickel ternary cathode material, which can improve the lithium-ion diffusion rate during the charge and discharge process, effectively reduce the erosion of the electrolyte on the main body of the cathode material, thereby reducing the battery impedance, improving the residual alkali and electrochemical performance on the material surface, improving the cycle stability of the cathode material, and alleviating the thermal stability of the high-nickel cathode material.

[0005] The patent application of the invention with the publication number CN116799291A discloses a NASICON-type solid electrolyte, a cathode material, a preparation method thereof, and an application thereof. The chemical structural formula of the NASICON-type solid electrolyte is Li 1+x M 1 xTi 2-x (PO4) y (M 2 O4) z, where \(0\leq x\leq0.6\), \(1.5\leq z\leq4.5\), \(50\%\leq z / (y + z)\leq100\%\); \(M1\) includes at least one of \(Al\), \(Y\), \(Fe\), \(Cr\), \(Nb\), \(Zr\); \(M2\) includes at least one of \(V\), \(Mo\), \(W\), \(Nb\). By introducing transition metal elements and limiting the proportion of transition metal elements, the electronic conductivity of the solid electrolyte is maximized, enabling the solid electrolyte to possess dual conduction properties of lithium-ion conduction and electron conduction. The NASICON type with electron-ion dual conduction properties described in this invention patent is used as the coating material for coating and modifying the ternary lithium-ion battery cathode material.

[0006] The patent application of the invention with the publication number CN117199308A discloses that there are two side coating layers wrapped on the cathode material. The first coating layer is a fast ion conductor coating layer, and the second coating layer is a boride coating layer. This patent application utilizes the chemical inertness of the first layer of coating to reduce the contact between the electrolyte and the cathode material and improve the transport efficiency of lithium ions during charge and discharge. Utilizing the mechanical properties of the second coating layer, it effectively prevents the electrolyte from eroding the cathode material, simultaneously inhibits the stress and strain of the cathode material during the insertion and extraction of lithium ions, alleviates the generation of microcracks, and at the same time utilizes the conductivity of the boride to form a stable coating layer. However, the functions of the first and second coating layers mentioned in this patent application are mainly to prevent the electrolyte from eroding the cathode material, and there is no mention of how to dissipate the heat generated by the cathode material.

[0007] Although the above patent can improve the structural stability of the material at high voltages and the interfacial stability with the electrolyte to a certain extent through surface coating, and can promote the conduction of lithium ions by coating ion-conductive materials, such coating is prone to cause a decrease in the electronic conductivity of the material and affect the diffusion of lithium ions and the dissipation of heat generation.

[0008] Therefore, there is an urgent need to design a coated high-nickel material with high surface ion / electron conductivity, easy heat dissipation, and good compatibility with the electrolyte. Summary of the Invention

[0009] The present invention provides a coated high-nickel material, which has high surface ion / electron conductivity, easy heat dissipation, and good compatibility with the electrolyte.

[0010] To achieve the above object, the present invention provides a coated high-nickel material, comprising a high-nickel material and a coating layer that wraps the surface of the high-nickel material, and the coating layer is obtained by mixing a NASICON type fast ion conductor and a metal boride.

[0011] The present invention utilizes NASICON-type fast ion conductors to improve the lithium ion transport performance and electrochemical stability between the high-nickel electrode material and the electrolyte interface, while suppressing the generation of high-impedance impurities to avoid a significant reduction in electronic conductivity. However, simply coating the NASICON-type fast ion conductor will inevitably reduce the electronic conductivity of the battery. Therefore, the present invention mixes metal boride in the coating layer to enhance the electronic conductivity while ensuring the lithium ion transport performance and electrochemical stability. Thus, through the synergistic effect of the NASICON-type fast ion conductor and metal boride, the present invention optimizes the transport paths of ions and electrons inside the battery, which can accelerate the transport of ions and electrons between the electrolyte and the electrode material, contributing to improving the charge-discharge efficiency and energy utilization rate.

[0012] The present invention can construct a heat transfer channel by mixing metal boride in the coating layer to transfer heat from the inside of the high-nickel material to the outside of the coating layer. The NASICON-type fast ion conductor can further promote the diffusion of heat through its three-dimensional network open structure, endowing the coating layer with excellent thermal conductivity to accelerate heat dissipation.

[0013] The present invention provides that the high melting point and high thermal conductivity of metal boride help prevent the battery from experiencing thermal runaway at high temperatures, while the structural stability of the NASICON-type fast ion conductor helps maintain the normal operation of the battery under harsh conditions. Thus, the present invention achieves good thermal stability through the synergistic effect of the NASICON-type fast ion conductor and metal boride.

[0014] Preferably, the weight ratio of the NASICON-type fast ion conductor to the metal boride is 1:3 to 3:1.

[0015] By providing an appropriate amount of the NASICON-type fast ion conductor and metal boride, the present invention can achieve an optimized balance of the electronic conductivity, ionic conductivity, thermal conductivity, and electrode / electrolyte interface stability of the coated high-nickel material, avoiding the situation where too low a content of the NASICON-type fast ion conductor is unfavorable for the transport of interfacial lithium ions, and too much metal boride will also hinder the effective transport of lithium ions, resulting in a decline in battery performance. At the same time, it avoids too low a content of metal boride, which is unfavorable for electron transport and heat dissipation.

[0016] Preferably, the metal boride is selected from at least one of TiB2, ZrB2, HfB2, and NbB2. The metal boride provided by the present invention has good electronic conductivity, thermal conductivity, and wear resistance. By coating with the metal boride, the electronic conductivity and thermal conductivity of the material can be improved, thereby improving the rate performance and safety performance of the material. At the same time, the metal boride coating can also improve the stability of the coated high-nickel material in air and the processability. Compared with low-valence metal borides, the high-valence metal boride provided in this embodiment has better electronic conductivity and heat conduction performance.

[0017] If only NASICON-type Li 1+x Al x Ti 2-x (PO4)3 is coated, although it can improve the interfacial stability between LiNi x Co y Mn 1-x-y O2 and the electrolyte, thereby improving the cycle performance of the material, its electronic insulation is not conducive to the interfacial charge transfer reaction and the heat dissipation performance of the material; if only TiB2, ZrB2, HfB2, NbB2 are coated, although it is conducive to the interfacial charge transfer reaction and heat dissipation, it is not conducive to the transport of lithium ions at the LiNi x Co y Mn 1-x-y O2 / electrolyte interface.

[0018] More preferably, the particle size of the metal boride is 50-200 nm. The nanoscale metal boride provided by the specific embodiments of the present invention can improve the coating effect on the high-nickel material.

[0019] Preferably, the chemical general formula of the NASICON-type fast ion conductor is Li 1+x Al x Ti 2-x (PO4)3, where 0.2 ≤ x ≤ 0.5. The NASICON-type Li 1+x Al x Ti 2-x (PO4)3 provided by the present invention has excellent hydrophobicity, air stability, and high lithium ion conductivity, and is compatible with the synthesis conditions of LiNi x Co y Mn 1-x-y O2, that is, the thermodynamic synthesis conditions of the two are similar. By coating, the surface structure of LiNi x Co y Mn 1-x-y O2 can be stabilized, surface lattice distortion and oxygen evolution can be inhibited, and the safety performance of the material and the battery can be improved. At the same time, Li 1+x Al x Ti 2-x(PO4)3 coating can improve the interfacial stability between LiNi x Co y Mn 1-x-y O2 and the electrolyte, thus improving the cycling performance of the material. In addition, Li 1+x Al x Ti 2-x (PO4)3 coating can also improve the interfacial transport property of lithium ions between LiNi x Co y Mn 1-x- y O2 and the electrolyte.

[0020] Further preferably, the particle size of the NASICON-type Li 1+x Al x Ti 2-x (PO4)3 is 50 - 200 nm. The nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 particle material provided by the specific embodiments of the present invention can improve the coating effect on the high-nickel material, that is, a uniform and continuous coating layer can be formed.

[0021] Preferably, the chemical general formula of the high-nickel material is LiNi x Co y Mn 1-x-y O2, where 0.7 ≤ x < 1 and 0 < y < 0.2. The high-nickel material provided by the present invention has a relatively high capacity, which is beneficial to improving the energy density of the battery.

[0022] Preferably, the weight ratio of the coating layer to the high-nickel material is 0.2 - 2:100. By controlling the content of the coating layer, the present invention enables the surface of the high-nickel material to be completely wrapped by the coating layer, avoiding the exposure of the high-nickel material, and at the same time can avoid the excessive thickness of the coating layer affecting heat dissipation and the surface ion / electron conductivity.

[0023] On the other hand, the present invention also provides a preparation method of the coated high-nickel material, including:

[0024] (1) Mixing the nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 and the nanoscale metal boride uniformly to obtain a mixture of Li 1+x Al x Ti 2-x (PO4)3 and the metal boride;

[0025] (2) By using the mechanical fusion method, the mixture in step (1) is coated on the surface of high-nickel material particles by rotating the cylinder body to obtain the coated high-nickel material, wherein blades are fixed on the cylinder wall of the cylinder body. During the rotation of the cylinder body, the mixture and the high-nickel material particles are closely attached to the cylinder wall and are fully mixed under the extrusion of the fixed blades.

[0026] Preferably, the preparation method of the nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 includes:

[0027] Weigh sodium dihydrogen phosphate, alumina, titanium oxide and a lithium source according to the stoichiometric ratio, and obtain a mixture through ball milling;

[0028] Perform a solid-phase reaction on the mixture in an air atmosphere, and then obtain Li 1+x Al x Ti 2-x (PO4)3 through sand milling.

[0029] Further preferably, the temperature of the solid-phase reaction is 850-950 o °C, and the reaction time is 5-10 hours.

[0030] Further preferably, after sand milling, the particle size of Li 1+x Al x Ti 2-x (PO4)3 is 50-200 nanometers.

[0031] Preferably, the preparation method of the nanoscale metal boride includes: using a sand milling process to crush the metal boride to obtain a nanoscale metal boride. The metal boride provided by the present invention is a commercially available material. As a preference, after sand milling, the particle size of the metal boride is 50-200 nanometers.

[0032] Preferably, in step (1), the mixing method is the ball milling method or the high-speed mixing method. <>

[0033] Further preferably, in step (1), the mixing method is the high-speed mixing method. By using the high-speed mixing method, the shear force during the high-speed mixing can make the nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 and the nanoscale metal boride achieve uniform mixing.

[0034] On the other hand, the present invention also provides the application of the coated high-nickel material in a lithium-ion battery.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] The present invention uses a coating layer composed of NASICON-type fast ion conductor and metal boride to coat a high-nickel material, so as to stabilize the crystal structure of the high-nickel material. Different from the conventional method of separately coating the NASICON-type fast ion conductor and metal boride in layers, the present invention mixes the NASICON-type fast ion conductor and metal boride into one layer and coats it on the cathode material. The purpose is not only to optimize the ion and electron transport paths inside the battery to facilitate the acceleration of ion and electron transport, but also to utilize the heat transport channels constructed by the metal boride to cooperate with the three-dimensional network open structure of the NASICON-type fast ion conductor to promote heat diffusion, so that the coating layer has excellent thermal conductivity and can accelerate heat dissipation.

[0037] In the application of the lithium battery prepared with the coated high-nickel material prepared by the present invention, when charged and discharged at 1 C (1 C = 200 mA / g) for 200 times, the capacity retention rate is above 90%, showing high cycling performance. In the DSC test, the material decomposition temperature is above 243 °C, indicating a high decomposition temperature. Therefore, the coated high-nickel material provided by the present invention has high thermal stability and safety.

[0038] The mechanical fusion method provided by the present invention uniformly coats the mixture on the surface of the high-nickel material particles. It has a short operation time, can achieve one-piece molding, does not require a liquid binder during processing, and does not require drying or heating after processing. It has excellent uniformity and stability, etc. After adopting the mechanical fusion method, the crystal structure of the high-nickel material particles is not damaged by the mechanical fusion, and the structure and shape can be maintained intact, while the contour of the coating layer is smooth and the coating uniformity is good. Description of the Drawings

[0039] Figure 1 Schematic diagram of the structure of the coated high-nickel material prepared in Example 1.

[0040] Figure 2 Charge-discharge curve of the coated high-nickel material prepared in Example 1;

[0041] Figure 3 Cycling performance graph of the coated high-nickel material prepared in Example 1;

[0042] Figure 4 Morphology graph of the coated high-nickel material prepared in Example 1. Specific Embodiments

[0043] The present invention will be further described below in conjunction with the embodiments and the drawings.

[0044] Although in the prior art, it has been disclosed to use metal borides or fast ion conductors as the coating layer, or as disclosed in CN117199308A, use fast ion conductors as the first coating layer close to the cathode material and borides as the second coating layer, the main function of the disclosed borides is to prevent the electrolyte from contacting the cathode material and avoid side reactions between the electrolyte and the cathode material at high temperatures, which may cause cracks in the cathode material. This is different from the function of the present application, which rapidly dissipates the heat generated by the cathode material through the cooperation of borides and fast ion conductors. Therefore, the thermal stability characterization provided by this patent application is based on the decomposition of the electrolyte at the surface interface and the gas generation amount to illustrate the reaction degree between the cathode material and the electrolyte, while the specific embodiments of the present invention use the thermal decomposition temperature of the material for characterization to illustrate that the materials provided by the specific embodiments of the present invention have good heat dissipation effects. Therefore, although the above comparative document discloses the use of borides as the coating layer, the functions are different. The specific embodiments of the present invention for constructing a coating layer to wrap high-nickel materials by mixing NASICON-type fast ion conductors and metal borides are as follows:

[0045] Example 1: This example provides a preparation method for a coated high-nickel material, including:

[0046] Weigh according to the stoichiometric ratio of Li 1.3 Al 0.3 Ti 1.7 (PO4)3, use sodium dihydrogen phosphate, aluminum oxide, titanium oxide, and lithium carbonate as the precursors, and obtain Li 1.3 Al 0.3 Ti 1.7 (PO4)3 through ball milling and then solid-phase reaction, where the solid-phase reaction temperature is 900 o °C and the solid-phase reaction time is 7 hours.

[0047] Grind Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and commercial NbB2 separately by sand milling to obtain Li 1.3 Al 0.3 [[ID=…]] Ti 1.7 (PO4)3 and NbB2 powders with a particle size of 100 nanometers, and mix the two evenly by ball milling, with a weight ratio of 1:1.

[0048] Mix the above mixture with commercial LiNi 0.8 Co 0.1 Mn 0.1 O2 evenly by ball milling, where the mixture and LiNi 0.8 Co 0.1 Mn 0.1The weight ratio of O2 is 0.5:100, and then Li is obtained by mechanical fusion method 1.3 Al 0.3 Ti 1.7 (PO4)3 and NbB2 mixed particles are uniformly and completely coated on the surface of LiNi 0.8 Co 0.1 Mn 0.1 O2 particles, and the obtained coated high-nickel material is denoted as A40-250109-WB2. As shown in Table 1, the powder impedance of the coated high-nickel material prepared in this example is reduced by two orders of magnitude compared with the high-nickel material provided in Comparative Example 1. The value of the powder impedance is inversely proportional to the value of the electronic conductivity, that is, the smaller the powder impedance value of the cathode material, the higher the electronic conductivity value of the cathode material. The structure of the coating material is shown in Figure 1 , and the morphology diagram is as shown in Figure 4 . A mixed particle layer of Li 0.8 Co 0.1 Mn 0.1 O2 is wrapped on the surface 1.3 Al 0.3 Ti 1.7 (PO4)3 and NbB2

[0049] Using the material prepared in this example as the cathode, metallic lithium as the anode, a polypropylene membrane as the separator, and a 1 mol / L LiPF6 ethylene carbonate (EC) / diethyl carbonate (DEC) solution as the electrolyte, an assembled button battery is used for charge and discharge testing, and the voltage range is 3-4.3 V, as shown in Figure 2 . The discharge capacity is 191 mAh / g, and the capacity retention rate is 94% after 200 charge and discharge cycles at 1 C (1 C = 200 mA / g), as shown in Figure 3 . The above-mentioned coated material is charged to 4.3 V for DSC testing, and the material decomposition temperature is 252 o °C. The coating layer provided in this example is a coating layer formed by mixing a fast ion conductor and a metal boride, mainly by combining the heat conduction channels of the metal boride and the three-dimensional network open structure of the fast ion conductor to accelerate heat dissipation to achieve thermal stability

[0050] Example 2: This example provides a preparation method of a coated high-nickel material, including:

[0051] According to the stoichiometric ratio of Li 1.4 Al 0.4 Ti 1.6 (PO4)3, ingredients are prepared. Using sodium dihydrogen phosphate, aluminum oxide, titanium oxide, and lithium carbonate as precursors, through ball milling and mixing, and then through solid-phase reaction to obtain Li 1.4 Al 0.4 Ti1.6 (PO4)3. The solid-phase reaction temperature is 850 o °C, and the solid-phase reaction time is 10 hours.

[0052] Mix Li 1.4 Al 0.4 Ti 1.6 (PO4)3 and commercial TiB2 by sanding respectively to obtain Li 1.4 Al 0.4 Ti 1.6 (PO4)3 and TiB2 powders with a particle size of 200 nanometers, and mix the two evenly by ball milling. The weight ratio of the two is 3:1.

[0053] Mix the above mixture with commercial LiNi 0.85 Co 0.05 Mn 0.10 O2 evenly by ball milling. The weight ratio of the mixture to LiNi 0.85 Co 0.05 Mn 0.10 O2 is 1:100. Then, perform coating by mechanical fusion method to evenly and completely coat the Li 1.4 Al 0.4 Ti 1.6 (PO4)3 and TiB2 mixed particles on the surface of LiNi 0.85 Co 0.05 Mn 0.10 O2 particles.

[0054] Perform electrochemical tests according to the method of Example 1. Charge and discharge at 1 C for 200 times, and the capacity retention rate is 90.8%. Charge the above-coated material to 4.3 V and perform DSC test. The decomposition temperature is 243 o °C.

[0055] Comparative Example 1: Prepare the material according to the method of Example 1. The difference from Example 1 is that: The LiNi 0.8 Co 0.1 Mn 0.1 O2 material is not coated at all, and the obtained high-nickel material is denoted as A40-250109-WB1.

[0056] The rest is the same as in Example 1 and will not be elaborated here.

[0057] Perform electrochemical tests according to the method of Example 1. Charge and discharge at 1 C for 200 times, and the capacity retention rate is 75.8%. Charge the above material to 4.3 V and perform DSC test. The decomposition temperature is 227 o °C.

[0058] Table 1 shows the powder impedance of the high-nickel materials prepared in Example 1 and Comparative Example 1

[0059]

[0060] Comparative Example 2: The material was prepared by the method of Example 1, and the difference from Example 1 was that: LiNi 0.8 Co 0.1 Mn 0.1 The O2 material was only coated with Li 1.3 Al 0.3 Ti 1.7 (PO4)3 and not coated with NbB2.

[0061] The rest was the same as in Example 1 and will not be elaborated here.

[0062] Electrochemical tests were carried out according to the method of Example 1. Charging and discharging at 1 C for 200 cycles, the capacity retention rate was 83.6%. The above material was charged to 4.3 V, and by DSC test, the decomposition temperature was 231 o °C.

[0063] Comparative Example 3: The material was prepared by the method of Example 1, and the difference from Example 1 was that: LiNi 0.8 Co 0.1 Mn 0.1 The O2 material was only coated with NbB2 and not coated with Li 1.3 Al 0.3 Ti 1.7 (PO4)3.

[0064] The rest was the same as in Example 1 and will not be elaborated here.

[0065] Electrochemical tests were carried out according to the method of Example 1. Charging and discharging at 1 C for 200 cycles, the capacity retention rate was 84.6%. The above material was charged to 4.3 V, and by DSC test, the decomposition temperature was 236 o °C.

[0066] Comparative Example 4: The material was prepared by the method of Example 1, and the difference from Example 1 was that NbB2 was replaced with an equal weight of Nb2O5.

[0067] The rest was the same as in Example 1 and will not be elaborated here.

[0068] Electrochemical tests were carried out according to the method of Example 1. Charging and discharging at 1 C for 200 cycles, the capacity retention rate was 83.9%. The above material was charged to 4.3 V, and by DSC test, the decomposition temperature was 232 o °C.

Claims

1. A coated high-nickel material, characterized in that, It includes a high-nickel material and a coating layer that wraps the surface of the high-nickel material, and the coating layer is obtained by mixing a NASICON-type fast ion conductor and a metal boride; The weight ratio of the NASICON-type fast ion conductor to the metal boride is 1:3 to 3:1; The chemical general formula of the NASICON-type fast ion conductor is Li 1+x Al x Ti 2-x (PO4)3, where 0.2 ≤ x ≤ 0.5; The preparation method of the coated high-nickel material includes: (1) Mix nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 and nanoscale metal boride evenly to obtain a mixture of Li 1+ x Al x Ti 2-x (PO4)3 and metal boride; (2) Using the mechanical fusion method, the mixture in step (1) is coated on the surface of the high-nickel material particles by rotating the cylinder body to obtain the coated high-nickel material. Blades are fixed on the cylinder wall of the cylinder body. During the rotation of the cylinder body, the mixture and the high-nickel material particles are closely attached to the cylinder wall and are fully mixed under the extrusion of the fixed blades; The nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 is prepared by solid-phase reaction, the temperature of the solid-phase reaction is 850-950 °C, and the reaction time is 5-10 hours.

2. The coated high-nickel material according to claim 1, wherein The metal boride is selected from at least one of TiB2, ZrB2, HfB2, and NbB2.

3. The coated high-nickel material according to claim 2, wherein The particle size of the metal boride is 50 to 200 nm.

4. The coated high-nickel material according to claim 1, wherein The NASICON-type Li 1+x Al x Ti 2-x (PO4)3 particle size is 50 - 200 nm.

5. The coated high-nickel material according to claim 1, wherein The weight ratio of the coating layer to the high-nickel material is 0.2 to 2:

100.

6. The coated high-nickel material according to claim 1, characterized in that, The chemical general formula of the high-nickel material is LiNi x Co y Mn 1-x-y O2, where 0.7 ≤ x < 1 and 0 < y < 0.

2.

7. A method for preparing the coated high-nickel material according to any one of claims 1-6, characterized in that, It includes: (1) Mix nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 and nanoscale metal boride evenly to obtain a mixture of Li 1+ x Al x Ti 2-x (PO4)3 and metal boride; (2) Using the mechanical fusion method, the mixture in step (1) is coated on the surface of the high-nickel material particles by rotating the cylinder body to obtain the coated high-nickel material. Blades are fixed on the cylinder wall of the cylinder body. During the rotation of the cylinder body, the mixture and the high-nickel material particles are closely attached to the cylinder wall and are fully mixed under the extrusion of the fixed blades; The nanoscale NASICON-type Li 1+x Al x Ti 2-x (PO4)3 is prepared by solid-phase reaction. The temperature of the solid-phase reaction is 850 to 950 °C, and the reaction time is 5 to 10 hours.

8. Application of the coated high-nickel material according to any one of claims 1-6 in a lithium-ion battery.

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