A Preparation Method of a Low-Cost High-Nickel Cathode Material

Abstract

The present invention discloses a preparation method of a high-nickel cathode material with low cost. A transition metal hydroxide precursor and a lithium source are uniformly mixed and pre-sintered at 300-550 °C in an oxygen-containing atmosphere to obtain a first sintered material; the first sintered material, a first additive and a second additive are uniformly mixed and secondarily sintered at 700-850 °C in an oxygen-containing atmosphere to obtain a second sintered material; the second sintered material is crushed, centrifugally washed and dried to obtain a cathode material matrix; the cathode material matrix and a boron-containing compound are uniformly mixed and low-temperature sintered at 200-400 °C in an oxygen atmosphere to obtain a high-nickel cathode material. The high-nickel cathode material prepared by the present invention has the characteristics of high structural stability, high particle mechanical strength and excellent cyclic use performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of high-nickel cathode materials for lithium-ion batteries, and particularly relates to a preparation method of a low-cost high-nickel cathode material. Background Art

[0002] Lithium-ion batteries have been widely used in fields such as automobiles, mobile phones, and power tools. As the research on the core cathode materials in lithium-ion batteries, some products have entered the industrialization stage, but a series of problems brought about by industrial production have restricted the further development of lithium-ion cathode materials. With the increasing demand for high-energy-density batteries in new energy vehicles and portable electronic devices, the cathode material, as the main Li + donor, the improvement of its performance is crucial for increasing the energy density of the battery. Moreover, the shortage and rising price of cobalt resources have greatly increased the production cost of lithium-ion batteries. High-nickel and low-cobalt or even cobalt-free cathode materials have become a research hotspot due to their high energy density and low cost. However, high-nickel cathode materials have serious microcrack problems. During the cycling process, anisotropic shrinkage or expansion causes changes in lattice parameters, which become more and more serious as the depth of discharge increases. These microcracks will have unnecessary side reactions with the electrolyte during the cycling process, resulting in poor cycling performance.

[0003] The patent document of CN115602830 A discloses improving the production capacity through a pre-oxidation process, precisely controlling the water-to-material ratio, water washing time, water washing temperature, etc., controlling the BET of the ternary material after water washing and drying, and the D104 ratio at 30% SOC ≥ 0.3, to obtain a ternary material with a crystal structure and excellent comprehensive performance such as cycling and gas production. However, the preferred water washing time in this patented technology is only 2 - 3 minutes, which is difficult to control during actual batch production.

[0004] The patent document of CN114520318B discloses preparing a nickel-tungsten-manganese hydroxide precursor with uniformly doped W, Zr, and Al inside and solid-phase doping of nano-additives Ba, Mo, etc. on the external surface through a liquid-phase co-precipitation method and precise morphology control, and then sintering and compounding at high temperature to improve the structural stability of the high-nickel cobalt-free cathode material. Then, by wet-coating the surface to modify the nano-coating to convert the residual alkali of the cathode material into a composite lithium-ion metal conductor coating layer to improve the cycling and high-temperature performance, etc. Finally, a high-nickel cobalt-free lithium nickel tungsten manganate cathode material with both low cost and high performance is obtained through dynamic high-temperature heat treatment. There are many doped elements in this patented technology, which have a greater impact on the capacity in subsequent production.

[0005] Patent document CN111816877A discloses that a high-nickel binary positive electrode material precursor is mixed evenly with a compound containing M and N and a lithium source, calcined in an oxygen atmosphere, and the calcined material is ground and sieved to obtain a high-nickel cobalt-free quaternary positive electrode material. In this preparation process, the precursor, lithium source and doping compound are directly mixed evenly and then sintered, and there is no pre-sintering step of the precursor and the lithium source.

[0006] The patent document of CN115275183A discloses that nickel salt, zirconium salt, aluminum salt and lithium salt are dissolved in deionized water and stirred thoroughly to obtain solution A; reducing agent solution B is added to solution A and stirred thoroughly to obtain solution C; solution C is heated in a water bath and stirred continuously until a gel is formed; the gel is dried thoroughly to obtain a block powder; the block powder is ground and calcined to obtain a cobalt-free high-nickel positive electrode material for lithium-ion batteries. The preparation process prepares doped high-nickel positive electrode materials by a sol-gel method, and there is no pre-sintering step of the precursor and the lithium source and the secondary sintering step after the doping compound is mixed.

[0007] The patent document of CN115810745A discloses that the precursor and the metal source fine powder are weighed and mixed in accordance with the metering ratio to obtain a mixture 1; the lithium source is weighed and mechanically mixed with the mixture 1, and the mixture 2 is mixed to obtain a mixture 2; the mixture 2 is placed in a tube furnace, and in an oxygen atmosphere, the temperature is first raised to 450-550°C and kept warm for 3-5 hours; the temperature is then raised to 740-780°C and kept warm for 12-18 hours; the product obtained after calcination is ground and sieved after cooling to room temperature to obtain the product. In this preparation process, the precursor, the metal source fine powder, and the lithium source are mixed in sequence and then sintered, and there is no pre-sintering link of the precursor and the lithium source. Summary of the invention

[0008] The technical problem solved by the present invention is to provide a method for preparing a low-cost high-nickel positive electrode material. The high-nickel positive electrode material prepared by the method has the characteristics of high structural stability, high particle mechanical strength and excellent recycling performance.

[0009] The present invention adopts the following technical solution to solve the above technical problems, a method for preparing a low-cost high-nickel positive electrode material, characterized by the specific steps of:

[0010] Step S1, uniformly mixing a transition metal hydroxide precursor and a lithium source and pre-sintering them at 300-550° C. in an oxygen-containing atmosphere to obtain a first sintered material;

[0011] Step S2, uniformly mixing the first sintered material with the first additive and the second additive and performing secondary sintering at 700-850° C. in an oxygen-containing atmosphere to obtain a second sintered material, wherein the first additive is a compound containing at least one of Al or B elements, and the second additive is a compound containing at least one of Zr, Nb, Ta or Y elements;

[0012] Step S3: Crush, centrifugally wash, and dry the second sintered material to obtain the cathode material matrix.

[0013] Step S4: Mix the cathode material matrix with a boron-containing compound evenly and perform low-temperature sintering at 200 - 400 °C in an oxygen atmosphere to obtain the high-nickel cathode material.

[0014] The chemical general formula of the high-nickel cathode material is Li a [Ni x Mn y M b N c O2], where 0.8 ≤ x < 1, 0 ≤ y ≤ 0.2, b + c ≤ 0.008, x + y + b + c = 1, 0.98 ≤ a ≤ 1.2, M is at least one of Al or B elements, N is at least one of Zr, Nb, Ta, or Y elements. This high-nickel cathode material has a crystal structure of a dual-stable material, M is distributed inside the material bulk phase, and N is distributed between the primary particle grain boundaries and on the particle surface to form a doping layer.

[0015] During the preparation process of the present invention, adding a pre-sintering process before the high-temperature calcination of the transition metal hydroxide precursor and the lithium source to remove the water in the transition metal hydroxide or the lithium source can effectively increase the loading amount of the material for the high-temperature solid-phase reaction and reduce the production cost; by controlling the oxygen content in the pre-sintering process, increasing the content of Ni 3+ in the material, after pre-sintering, performing crushing and mixing treatments to promote the reaction with lithium in the high-temperature stage, and at the same time combining different properties of additives introduced in the high-temperature calcination process, elements with small ionic radii enter the internal lattice of the material, while elements with large ionic radii are in the material grain boundaries and between primary particles, synergistically improving the particle mechanical strength and structural stability of the cathode material, and finally obtaining a high-nickel cathode material with excellent cycle performance.

[0016] In the high-nickel cathode material Li a [Ni x Mn y M b N c O2] of the present invention, M is an element with an ionic radius smaller than that of Ni and Mn ions, such as Al (0.053 Å ), B (0.027 Å ), etc.; N is an element with an ionic radius larger than that of Ni and Mn ions, such as Zr (0.072 Å ), Ta (0.064 Å ), Y (0.09 Å ), Nb (0.064 Å) and other elements. Since the M ion radius is small, it is easy to be distributed in the bulk of the material during the high-temperature solid phase reaction process, while the N ion radius is large and is distributed between the grain boundaries of the primary particles and on the surface of the particles to form a doping layer, ultimately forming a crystal structure with dual-stable materials, thereby improving the particle stability of the high-nickel positive electrode material and enhancing its electrochemical performance.

[0017] It is further defined that the average particle size of the transition metal hydroxide precursor in step S1 is 5-15 μm, and the particle size distribution is 0.6-1.5; the lithium source is at least one of lithium hydroxide, lithium hydroxide monohydrate, lithium carbonate or lithium nitrate, and the average particle size of the lithium source is 8-300 μm.

[0018] It is further defined that the molar ratio of the lithium source to the nickel manganese hydroxide precursor in step S1 is 0.98-1.2:1.

[0019] It is further defined that the volume percentage of oxygen in the oxygen-containing atmosphere in step S1 is 10% to 25%, and the oxygen-containing atmosphere is preferably an air atmosphere. The pre-sintering process in the oxygen-containing atmosphere can increase the Ni content in the transition metal compound. 3+ The content of Ni 3+ Higher activity is conducive to the high-temperature solid-phase reaction of lithium and transition metals during the secondary sintering process. If the oxygen content is too high, due to the low temperature of the pre-sintering process, the oxidation reaction is insufficient, which is not conducive to the formation of a layered structure and easily generates impure phases.

[0020] It is further defined that the heating rate of the pre-sintering process in step S1 is 1-5°C / min. The material powder has good fluidity. If the heating rate is too fast, the water will evaporate too quickly and the material will splash.

[0021] It is further defined that the pre-sintered material in step S1 is cooled and then crushed and mixed to obtain the first sintered material. Since the pre-sintered material is slightly agglomerated, the crushing and mixing process allows the material to react more evenly and fully in the high-temperature solid phase reaction process.

[0022] It is further defined that the volume percentage of oxygen in the oxygen-containing atmosphere in step S2 is ≥ 90%.

[0023] It is further defined that the compound in step S2 is one of oxides, chlorides or hydroxides containing the corresponding element.

[0024] It is further defined that the boron-containing compound in step S4 is at least one of boron oxide or boric acid.

[0025] Further defined, the high-nickel cathode material described in step S4 is subjected to powder sample preparation under a pressure of 150-200 MPa, and the difference in the average particle size D50 of the powder is <2 μm, indicating that the prepared high-nickel cathode material has relatively high particle strength.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects: The present invention studies the problems of high cost of high-nickel cathode materials, poor particle strength, poor structural stability, and poor electrical performance during charge and discharge. On the one hand, by controlling the oxygen concentration during the pre-sintering process, the content of trivalent nickel before the high-temperature solid-phase reaction is increased. Trivalent nickel has higher reaction activity, and after pre-sintering, the process of crushing and mixing is added, so that the reaction with lithium in the high-temperature solid-phase reaction of the precursor is more uniform and sufficient, and the crystal structure is more complete, which is beneficial to improving the strain caused by the change in the unit cell volume of the high-nickel cathode material during charge and discharge, and thus improving the cycle stability performance; on the other hand, by doubly introducing doping elements during the secondary high-temperature calcination process, elements with small ionic radii enter the interior of the material bulk phase, and elements with large ionic radii are distributed between the grain boundaries and on the surface of the primary particles to form a doping layer, finally forming a crystal structure with a double-stable material, thereby improving the particle stability of the high-nickel cathode material and enhancing its electrochemical performance. Description of the Drawings

[0027] Figure 1 It is a scanning electron microscope image of the cathode material prepared in Example 1.

[0028] Figure 2 It is a scanning electron microscope image of the cathode material prepared in Comparative Example 1.

[0029] Figure 3 It is an XRD pattern of the cathode material prepared in Example 1.

[0030] Figure 4 It is a cyclic test curve of a button cell assembled with the cathode materials prepared in Examples 1-4 and Comparative Examples 1-2. Detailed Embodiments

[0031] The above content of the present invention will be further described in detail below through examples, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following examples. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0032] Select a transition metal hydroxide with the chemical formula Ni 0.9 Mn 0.1 (OH)2 and D50 of 10.073 μm as the precursor used in the examples and comparative examples. Example 1

[0033] According to Li 1.05 Ni 0.892 Mn0.1 Al 0.005 Nb 0.003 The raw materials LiOH·H2O, Ni 0.9 Mn 0.1 (OH)2 precursor, nanoscale Al2O3 and Nb2O5 are weighed respectively according to the stoichiometric ratio of O2;

[0034] LiOH·H2O and Ni 0.9 Mn 0.1 (OH)2 precursor are mixed evenly by a high-speed mixer and pre-sintered. The pre-sintering temperature is 500 °C, the pre-sintering time is 5 h, the heating rate is 2 °C / min, the atmosphere is air atmosphere, the flow rate is 50 L / min, the measured oxygen volume percentage is 20.75%, and after natural cooling, it is broken and mixed to obtain pre-sintered materials;

[0035] The pre-sintered materials, nanoscale Al2O3 and Nb2O5 are mixed evenly by a high-speed mixer and then secondarily sintered. The secondary sintering temperature is 800 °C, the secondary sintering time is 10 h, the atmosphere is oxygen atmosphere, the flow rate is 60 L / min, the measured oxygen volume percentage is 95.2%, and after natural cooling, it is broken and pulverized to obtain secondarily sintered materials;

[0036] The secondarily sintered materials and pure water are mixed according to the mass ratio of 1:1 and centrifugally washed. The rotation speed is set at 400 r / min, the washing time is 15 min, and then pressure filtration and drying are carried out to obtain the cathode material matrix;

[0037] The cathode material matrix and H3BO3 are mixed evenly and low-temperature sintered. The low-temperature sintering temperature is 300 °C, the low-temperature sintering time is 6 h, the atmosphere is oxygen atmosphere, and after natural cooling, it is sieved to obtain the low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.005 Nb 0.003 O2. Example 2

[0038] According to Li 1.05 Ni 0.892 Mn 0.1 Al 0.005 Zr 0.003 The raw materials LiOH·H2O, Ni 0.9 Mn 0.1 (OH)2 precursor, nanoscale Al2O3 and ZrO2 are weighed respectively according to the stoichiometric ratio of O2;

[0039] LiOH·H2O and Ni 0.9 Mn 0.1(OH)2 precursor is mixed evenly by a high-speed mixer and pre-sintered. The pre-sintering temperature is 500 °C, the pre-sintering time is 5 h, the heating rate is 2 °C / min, the atmosphere is air atmosphere, the flow rate is 50 L / min, the measured oxygen volume percentage is 20.6%, and it is cooled naturally and broken and mixed to obtain the pre-sintered material;

[0040] The pre-sintered material is mixed evenly with nano-level Al2O3 and ZrO2 by a high-speed mixer and then subjected to secondary sintering. The secondary sintering temperature is 800 °C, the secondary sintering time is 10 h, the atmosphere is oxygen atmosphere, the flow rate is 60 L / min, the measured oxygen volume percentage is 96%, and after natural cooling, it is broken and pulverized to obtain the secondary sintered material;

[0041] The secondary sintered material and pure water are mixed in a mass ratio of 1:1 and centrifugally washed. The rotation speed is set at 400 r / min, the washing time is 15 min, and then pressure filtration and drying are carried out to obtain the cathode material matrix;

[0042] The cathode material matrix is mixed evenly with H3BO3 and subjected to low-temperature sintering. The low-temperature sintering temperature is 300 °C, the low-temperature sintering time is 6 h, the atmosphere is oxygen atmosphere, and after natural cooling, it is sieved to obtain the low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.005 Zr 0.003 O2. Example 3

[0043] In this example, except that the amounts of nano-level Al2O3 and Nb2O5 are different during the secondary sintering process, the rest are the same as in Example 1, and finally the low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.006 Nb 0.002 O2. Example 4

[0044] In this example, except that the amounts of nano-level Al2O3 and ZrO2 are different during the secondary sintering process, the rest are the same as in Example 2, and finally the low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.006 Zr 0.002 O2.

[0045] Comparative Example 1

[0046] According to Li 1.05 Ni 0.892 Mn 0.1 Al 0.005 Zr0.003 Weigh the raw materials LiOH·H2O, Ni 0.9 Mn 0.1 (OH)2 precursor, nano-sized Al2O3 and ZrO2 respectively according to the stoichiometric ratio of O2;

[0047] Mix the Ni 0.9 Mn 0.1 (OH)2 precursor with LiOH·H2O, nano-sized Al2O3 and ZrO2 uniformly by a high-speed mixer, then sinter them. The sintering temperature is 800 °C, the sintering time is 10 h, the atmosphere is oxygen atmosphere, and the flow rate is 60 L / min. Test the oxygen volume percentage content to be 94.5%. After natural cooling, obtain the sintered material through crushing and grinding;

[0048] Mix the sintered material and pure water according to the mass ratio of 1:1 and conduct centrifugal washing. Set the rotation speed to 400 r / min and the washing time to 15 min. Then perform pressure filtration and drying to obtain the cathode material matrix;

[0049] Mix the cathode material matrix and H3BO3 uniformly and conduct low-temperature sintering. The sintering temperature is 300 °C, the sintering time is 6 h, the atmosphere is oxygen atmosphere. After natural cooling, sieve to obtain the low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.005 Zr 0.003 O2.

[0050] Comparative Example 2

[0051] Weigh the raw materials LiOH·H2O, Ni 1.05 Ni 0.892 Mn 0.1 Al 0.008 O2 respectively according to the stoichiometric ratio of O2, and weigh the raw materials LiOH·H2O, Ni 0.9 Mn 0.1 (OH)2 precursor and nano-sized Al2O3;

[0052] Mix LiOH·H2O and Ni 0.9 Mn 0.1 (OH)2 precursor uniformly by a high-speed mixer and conduct pre-sintering. The pre-sintering temperature is 500 °C, the pre-sintering time is 5 h, the heating rate is 2 °C / min, the atmosphere is air atmosphere, and the flow rate is 50 L / min. Test the oxygen volume percentage content to be 20.6%. After natural cooling, crush and mix to obtain the pre-sintered material;

[0053] The pre-sintered material and nano-scale Al2O3 are mixed evenly by a high-speed mixer and then subjected to secondary sintering. The secondary sintering temperature is 800 °C, the secondary sintering time is 10 h, the atmosphere is oxygen, the flow rate is 60 L / min, the measured oxygen volume percentage is 95%, and after natural cooling, the material after secondary sintering is obtained through crushing and pulverization;

[0054] The material after secondary sintering and pure water are mixed in a mass ratio of 1:1 for centrifugal washing. The rotation speed is set to 400 r / min, the washing time is 15 min, and then pressure filtration and drying are carried out to obtain the cathode material matrix;

[0055] The cathode material matrix and H3BO3 are mixed evenly and then subjected to low-temperature sintering. The low-temperature sintering temperature is 300 °C, the low-temperature sintering time is 6 h, the atmosphere is an oxygen atmosphere, and after natural cooling, a low-cost high-nickel cathode material Li 1.05 Ni 0.892 Mn 0.1 Al 0.008 O2 is obtained by sieving.

[0056] Evaluation method of the material:

[0057] Test of the difference in average particle size:

[0058] Using a powder resistance instrument, in an environment with a temperature of 25 ± 2 °C and a relative humidity of less than 40 RH%, the prepared cathode material is placed on the sample stage, pressed under a pressure of 200 MPa, and the pressed powder is ground in a mortar to prepare a sample for testing the particle size after pressing. △D50μm = average particle size before pressing - average particle size after pressing. If the particles of the prepared cathode material are severely broken, more side reactions are likely to occur with the electrolyte during charge and discharge, resulting in poor cycle performance.

[0059] Test of particle size:

[0060] It can be tested according to the common methods and equipment for powder particle size, such as a Malvern laser particle size analyzer, etc.

[0061] Test of electrical properties:

[0062] Using the low-cost high-nickel cathode materials prepared in the examples and comparative examples as active substances respectively, they are coated on aluminum foil to prepare cathode sheets with a surface density of 80 - 100 m 2 / g and a pole piece compaction density of 3.0 - 3.4 g / cm 3 , and lithium sheets are used as the negative electrode to assemble button cells. The assembled cells are tested for charge-discharge capacity at 0.1C in the voltage range of 3.0 - 4.35V; and cyclic tested at 0.5C charge / 1C discharge at 23 °C in the voltage range of 3.0 - 4.3V.

[0063] Table 1 Particle size changes of the cathode materials prepared in Examples 1 - 4 and Comparative Examples 1 - 2

[0064]

[0065] Table 2 Specific capacity and cycling differences of the cathode materials prepared in Examples 1-4 and Comparative Examples 1-2

[0066]

[0067] In the present invention, by controlling the oxygen concentration during the pre-sintering process, the content of trivalent nickel before the high-temperature solid-phase reaction is increased. Trivalent nickel has higher reaction activity. After pre-sintering, the process of crushing and mixing is added to make the precursor react with lithium more uniformly and fully in the subsequent high-temperature solid-phase reaction, and the crystal structure of the generated material is more complete. It can be seen from the data in the table that on the basis of the same component precursor, the high-nickel cathode materials prepared in Examples 1-4 are subjected to powder sample preparation under a pressure of 150-200 MPa, with smaller powder particle size changes, more complete crystal structures, and stronger particle mechanical strength.

[0068] In the present invention, doping elements are introduced in a dual manner during the high-temperature calcination process. Elements with small ionic radii enter the interior of the material bulk phase, while elements with large ionic radii are distributed between the grain boundaries of primary particles and on the particle surface to form a doping layer, ultimately forming a crystal structure with a dual-stable material, thereby improving the particle stability of the high-nickel cathode material and reducing the generation of cracks during the pole piece rolling and charge-discharge processes. The button cells assembled with the high-nickel cathode materials prepared in Examples 1-4 as the active material have better capacity and cycling performance.

[0069] The above embodiments describe the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A preparation method of a low-cost high-nickel cathode material, characterized in that The specific steps are as follows: Step S1: Mix the transition metal hydroxide precursor and the lithium source evenly, and perform pre-sintering at 300 - 550 °C in an oxygen-containing atmosphere. After cooling the pre-sintered material, perform crushing and mixing treatment to obtain the first sintered material. The transition metal hydroxide precursor is a nickel-manganese hydroxide precursor with an average particle size of 5 - 15 μm and a particle size distribution of 0.6 - 1.

5. The lithium source is at least one of lithium hydroxide, lithium hydroxide monohydrate, lithium carbonate, or lithium nitrate, and the average particle size of the lithium source is 8 - 300 μm. The molar ratio of the lithium source to the nickel-manganese hydroxide precursor is 0.98 - 1.2:1, and the volume percentage of oxygen in the oxygen-containing atmosphere is 10% - 25%. Step S2: Mix the first sintered material, the first additive, and the second additive evenly, and perform secondary sintering at 700 - 850 °C in an oxygen-containing atmosphere to obtain the second sintered material. The first additive is a compound containing at least one of Al or B elements, and the second additive is a compound containing at least one of Zr, Nb, Ta, or Y elements. Step S3: Crush, centrifuge wash, and dry the second sintered material to obtain the cathode material matrix. Step S4: Mix the cathode material matrix and the boron-containing compound evenly, and perform low-temperature sintering at 200 - 400 °C in an oxygen atmosphere to obtain the high-nickel cathode material. The high-nickel cathode material is subjected to powder sample preparation under a pressure of 150 - 200 MPa, and the difference in the average particle size D50 of the powder is < 2 μm. The chemical general formula of the high-nickel cathode material is Li a [Ni x Mn y M b N c O2], where 0.8 ≤ x < 1, 0 ≤ y ≤ 0.2, b + c ≤ 0.008, x + y + b + c = 1, 0.98 ≤ a ≤ 1.2, M is at least one of Al or B elements, N is at least one of Zr, Nb, Ta or Y elements, the high-nickel cathode material has a crystal structure of a dual-stable material, M is distributed inside the material bulk phase, and N is distributed between the primary particle grain boundaries and on the particle surface to form a doping layer.

2. The preparation method of the low-cost high-nickel cathode material according to claim 1, characterized in that: The heating rate of the pre-sintering process in Step S1 is 1 - 5 °C / min.

3. The preparation method of the low-cost high-nickel cathode material according to claim 1, characterized in that: The volume percentage of oxygen in the oxygen-containing atmosphere in Step S2 is ≥ 90%.

4. The preparation method of the low-cost high-nickel cathode material according to claim 1, characterized in that: The compound in Step S2 is one of the oxides, chlorides, or hydroxides containing the corresponding elements.

5. The preparation method of the low-cost high-nickel cathode material according to claim 1, wherein: The boron-containing compound in Step S4 is at least one of boron oxide or boric acid.

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