Nickel-cobalt-manganese ternary precursor, preparation method therefor and use thereof

Abstract

A nickel-cobalt-manganese ternary precursor, a preparation method therefor and a use thereof. The nickel-cobalt-manganese ternary precursor comprises a core and a coating layer formed by stacking a plurality of primary particles on the surface of the core; the porosity of the core is greater than that of the coating layer; the particle size of the core is less than or equal to 1 μm; and the ratio of the radius of the core to the thickness of the coating layer is less than or equal to 1:2.75. The nickel-cobalt-manganese ternary precursor has an ultra-low specific surface area of 5 m2 / g or less, and has excellent dispersibility and uniformity. When the nickel-cobalt-manganese ternary precursor is used for preparing a positive electrode material, the specific surface area of the positive electrode material can be reduced, improving the cycle performance of the battery.

Description

Nickel-cobalt-manganese ternary precursor and its preparation method and application

[0001] This application claims the benefit of Chinese patent application No. 2023114452304, filed on October 31, 2023. This application incorporates the entirety of the aforementioned Chinese patent application. Technical Field

[0002] The present application relates to the technical field of lithium-ion batteries, and in particular to a nickel-cobalt-manganese ternary precursor and a preparation method and application thereof. Background Art

[0003] To address the global energy crisis, new energy vehicles are gaining increasing attention. Lithium-ion batteries, currently the best energy storage medium, have been widely used and researched in fields such as portable batteries and power batteries. However, the market is placing higher demands on power lithium-ion batteries. High energy density, high safety, long cycle life, good thermal stability, and low cost are key performance indicators for evaluating power batteries, with energy density and safety being the key considerations. Consequently, high-nickel cathode materials with layered structures are becoming the preferred choice for future lithium-ion batteries.

[0004] In order to further improve the driving range of new energy electric vehicles, improving the volume energy density of lithium-ion batteries has become a key factor. The specific capacity of lithium-ion batteries can be increased by increasing the charge and discharge voltage or further increasing the Ni content. However, the average particle size of traditional high-nickel ternary precursors is usually greater than 8μm. This is because small particle precursors of 3μm-8μm generally have a density greater than 6μm. 2 The specific surface area of ​​​​the material is too small, which will make the high-nickel single crystal cathode material prone to secondary microcracks during long cycles, leading to structural collapse and deterioration of electrochemical performance. Therefore, in order to meet the electrochemical performance requirements of high-nickel single crystal cathode materials, it is urgent to develop a small-particle ternary precursor with ultra-low specific surface area.

[0005] Summary of the Invention

[0006] Based on this, it is necessary to provide a nickel-cobalt-manganese ternary precursor and its preparation method and application for the above problems; the nickel-cobalt-manganese ternary precursor not only has 5m 2 / g, and has excellent dispersibility and uniformity. It can be used to prepare positive electrode materials to reduce the specific surface area of ​​the positive electrode materials, thereby improving the cycle performance of the battery.

[0007] A nickel-cobalt-manganese ternary precursor comprises a core and a coating layer formed by stacking a plurality of primary particles on the surface of the core, wherein the porosity of the core is greater than that of the coating layer, the particle size of the core is less than or equal to 1 μm, and the ratio of the radius of the core to the thickness of the coating layer is less than or equal to 1:2.75.

[0008] In one embodiment, the nickel-cobalt-manganese ternary precursor satisfies at least one of the following conditions:

[0009] (1) The volume of the core accounts for 0.5% to 4.0% of the volume of the nickel-cobalt-manganese ternary precursor;

[0010] (2) The particle size of the nickel-cobalt-manganese ternary precursor is less than or equal to 8 μm;

[0011] (3) The porosity of the coating layer is less than or equal to 1.5%;

[0012] (4) the porosity of the inner core is 1% to 5%;

[0013] (5) K of the nickel-cobalt-manganese ternary precursor 90 It is 0.50-0.55.

[0014] In one embodiment, the particle size of the nickel-cobalt-manganese ternary precursor is 3 μm-8 μm.

[0015] In one embodiment, the primary particles are obtained by stacking a plurality of sheet-like structures, and the thickness of the primary particles in the stacking direction of the sheet-like structures is 300 nm-500 nm.

[0016] In one embodiment, the molecular formula of the nickel-cobalt-manganese ternary precursor is Ni x Co y Mn z (OH)2, where x+y+z=1, and 0.8≤x≤0.9, 0 <y≤0.2,0<z≤0.2。

[0017] A method for preparing the nickel-cobalt-manganese ternary precursor as described above comprises the following steps:

[0018] A mixed metal salt solution is prepared by using soluble nickel salt, cobalt salt and manganese salt, and a base solution is prepared by using a first ammonia solution, a first alkali solution and water;

[0019] The mixed metal salt solution, the second ammonia solution and the second alkaline solution are continuously added to the bottom solution to perform a coprecipitation reaction. 50 After the particle size reaches the target size, the reaction is completed and a nickel-cobalt-manganese ternary precursor is obtained;

[0020] The coprecipitation reaction includes a first reaction stage, a second reaction stage and a third reaction stage, and meets the following conditions:

[0021] (1) The pH value of the second reaction stage is lower than the pH value of the first reaction stage, and the pH value of the third reaction stage is lower than the pH value of the first reaction stage;

[0022] (2) The stirring speed decreases gradually from the third reaction stage as the product particle size increases.

[0023] In one embodiment, the coprecipitation reaction satisfies at least one of the following conditions:

[0024] (1) The pH value of the third reaction stage is less than or equal to the pH value of the second reaction stage;

[0025] (2) the stirring speed of the first reaction stage is greater than or equal to the stirring speed of the second reaction stage;

[0026] (3) the flow rate of the mixed metal salt solution increases from the second reaction stage, and the flow rate of the mixed metal salt solution in the first reaction stage is less than the flow rate of the mixed metal salt solution in the third reaction stage;

[0027] (4) The ammonia value in the first reaction stage is greater than or equal to the ammonia value in the second reaction stage, and the ammonia value in the second reaction stage is greater than or equal to the ammonia value in the third reaction stage;

[0028] (5) The first reaction stage, the second reaction stage and the third reaction stage are all carried out under alkaline conditions.

[0029] In one embodiment, the coprecipitation reaction satisfies at least one of the following conditions:

[0030] (1) The difference between the pH value of the first reaction stage and the pH value of the second reaction stage is 0.3-0.5, and the pH value of the third reaction stage is equal to the pH value of the second reaction stage;

[0031] (2) In the third reaction stage, the stirring speed is controlled to decrease by 20 rpm to 30 rpm for every 0.5 μm to 1 μm increase in the particle size of the product, and the stirring speed in the first reaction stage is equal to the stirring speed in the second reaction stage;

[0032] (3) the difference between the flow rate of the mixed metal salt solution in the second reaction stage and the flow rate of the mixed metal salt solution in the first reaction stage is less than or equal to 15 L / h, the increase rate is less than or equal to 1.3 L / h, and the flow rate of the mixed metal salt solution in the third reaction stage is equal to the flow rate of the mixed metal salt solution at the end of the second reaction stage;

[0033] (4) The ammonia value in the second reaction stage is equal to the ammonia value in the third reaction stage.

[0034] In one embodiment, the coprecipitation reaction further satisfies at least one of the following conditions:

[0035] (1) The pH value of the first reaction stage is 11.3-12.6, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 330 rpm-600 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-30 L / h;

[0036] (2) The pH value of the second reaction stage is 11.1-12.2, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 330 rpm-600 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-40 L / h;

[0037] (3) The pH value of the third reaction stage is 11.1-12.2, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 100 rpm-550 rpm, and the flow rate of the mixed metal salt solution is 15 L / h-40 L / h.

[0038] In one embodiment, the time of the first reaction stage accounts for 0.5%-1.5% of the total coprecipitation reaction time, and the time of the second reaction stage accounts for 16%-25% of the total coprecipitation reaction time.

[0039] In one embodiment, the coprecipitation reaction further satisfies at least one of the following conditions:

[0040] (1) The flow rate of submerged nitrogen into the reaction solution is 100 L / h-800 L / h;

[0041] (2) The flow rate of submerged air introduced into the reaction solution is less than or equal to 300 L / h;

[0042] (3) The reaction temperature is 40°C-75°C;

[0043] (4) the concentration of the second ammonia solution is 1.0 mol / L-12.0 mol / L;

[0044] (5) the concentration of the second alkali solution is 1.0 mol / L-13.0 mol / L;

[0045] (6) The second alkaline solution is a sodium hydroxide solution.

[0046] In one embodiment, the mixed metal salt solution satisfies at least one of the following conditions:

[0047] (1) The total concentration of the mixed metal salt in the mixed metal salt solution is 1.2 mol / L-2.7 mol / L;

[0048] (2) Based on the total molar percentage of metal ions in the mixed metal salt solution as 100%, the molar percentage of nickel ions in the mixed metal salt solution is 80%-90%, the molar percentage of cobalt ions is less than or equal to 20%, and the molar percentage of manganese ions is less than or equal to 20%.

[0049] In one embodiment, the base liquid satisfies at least one of the following conditions:

[0050] (1) Ammonia value is 2g / L-10g / L;

[0051] (2) pH value is 11.3-12.6;

[0052] (3) The amount of water used is 100L-300L;

[0053] (4) The concentration of the first ammonia solution is 1.0 mol / L-12.0 mol / L;

[0054] (5) the concentration of the first alkali solution is 1.0 mol / L-13.0 mol / L;

[0055] (6) The first alkali solution is a sodium hydroxide solution.

[0056] A positive electrode material made from the nickel-cobalt-manganese ternary precursor.

[0057] A lithium-ion battery comprises the positive electrode material described above.

[0058] The nickel-cobalt-manganese ternary precursor described in this application not only has a small core particle size, which satisfies a specific ratio of core radius to coating thickness, but also has a lower porosity of the coating than the core, forming a loose inner and dense outer structure, thereby achieving a specific surface area reduction of 5m 2 / g or less, while making the nickel-cobalt-manganese ternary precursor have excellent dispersibility and uniformity. Therefore, the nickel-cobalt-manganese ternary precursor described in the present application solves the problems of high specific surface area and easy agglomeration of small-particle ternary precursors. When used to prepare positive electrode materials, it can not only significantly reduce the amount of residual lithium on the surface of the positive electrode material, effectively reduce the specific surface area of ​​the positive electrode material, and reduce the side reaction with the electrolyte during the positive electrode charge and discharge process, but also improve the lithium-nickel mixed arrangement phenomenon during the sintering process, reduce the generation of quasi-single crystals, and make the positive electrode material have excellent electrochemical properties such as high energy density and long cycle life.

[0059] In addition, the present application coordinates and controls the pH value and stirring speed of the reaction solution during the reaction process by time-dividing. On the one hand, the reaction particles grow slowly, thereby making the core volume of the precursor low and the coating layer thick and dense, forming a loose inner and dense outer structure; on the other hand, the reaction particles are highly dispersed, so that as the synthesis time increases, the primary particles grow radially, which is conducive to maintaining the uniformity of the precursor. In addition, during the synthesis process, the stirring speed is gradually reduced according to the particle size, which can also avoid the phenomenon of particle breakage caused by stirring, thereby improving the quality of the obtained precursor. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] FIG1 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Example 1 at different magnifications;

[0061] FIG2 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Example 2 at different magnifications;

[0062] FIG3 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Example 3 at different magnifications;

[0063] FIG4 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Comparative Example 1 at different magnifications;

[0064] FIG5 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Comparative Example 2 at different magnifications;

[0065] FIG6 is a scanning electron microscope image of the nickel-cobalt-manganese ternary precursor prepared in Comparative Example 3 at different magnifications. DETAILED DESCRIPTION

[0066] To facilitate understanding of the present application, the present application will be described in more detail below. However, it should be understood that the present application can be implemented in many different forms and is not limited to the embodiments or examples described herein. On the contrary, the purpose of providing these embodiments or examples is to make the understanding of the disclosure of the present application more thorough and comprehensive.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used in this specification are intended only to describe specific embodiments or examples and are not intended to limit this application.

[0068] The present application provides a nickel-cobalt-manganese ternary precursor, comprising a core and a coating layer formed by stacking a plurality of primary particles on the surface of the core, wherein the porosity of the core is greater than the porosity of the coating layer, the particle size of the core is less than or equal to 1 μm, and the ratio of the radius of the core to the thickness of the coating layer is less than or equal to 1:2.75.

[0069] The traditional nickel-cobalt-manganese ternary precursor cannot be reduced to 5m 2 / g or less, resulting in strong surface activity, and the particles are very easy to agglomerate to form large particles. The nickel-cobalt-manganese ternary precursor described in this application not only has a small core particle size, which meets the specific ratio of core radius to coating thickness, but also has a lower porosity of the coating than the core, forming a loose inner and dense outer structure, thereby achieving the goal of reducing the specific surface area to 5m 2 / g or less, while making the nickel-cobalt-manganese ternary precursor have excellent dispersibility and uniformity.

[0070] Preferably, the nickel-cobalt-manganese ternary precursor satisfies at least one of the following conditions:

[0071] (1) The volume of the core accounts for 0.5% to 4.0% of the volume of the nickel-cobalt-manganese ternary precursor;

[0072] (2) The particle size of the nickel-cobalt-manganese ternary precursor is less than or equal to 8 μm;

[0073] (3) The porosity of the coating layer is less than or equal to 1.5%;

[0074] (4) the porosity of the inner core is 1% to 5%;

[0075] (5) K of the nickel-cobalt-manganese ternary precursor 90 It is 0.50-0.55.

[0076] Controlling the volume ratio of the core within the above range helps to improve the uniformity of the nickel-cobalt-manganese ternary precursor; controlling the particle size of the nickel-cobalt-manganese ternary precursor within the above range helps to improve its processing performance, so as to prepare a high-nickel positive electrode material with good performance; controlling the porosity of the coating layer and the core within the above range helps to reduce the specific surface area of ​​the nickel-cobalt-manganese ternary precursor and improve the cycle performance of the positive electrode material prepared with the nickel-cobalt-manganese ternary precursor; controlling the K of the nickel-cobalt-manganese ternary precursor 90 Within the above range, the uniformity of the particle size distribution can be improved.

[0077] Further preferably, the particle size of the nickel-cobalt-manganese ternary precursor is 3 μm-8 μm, more preferably 3 μm-5 μm; the ratio of the radius of the inner core to the thickness of the coating layer is 1:9.75-1:2.75. The above limitations can further reduce the specific surface area of ​​the nickel-cobalt-manganese ternary precursor.

[0078] Preferably, the primary particles are obtained by stacking a plurality of flaky structures, and the thickness of the primary particles in the stacking direction of the flaky structures is 300 nm-500 nm, which is more conducive to improving the dispersion and uniformity of the precursor.

[0079] It should be noted that the thickness of the primary particles in the stacking direction of the sheet structure is 300 nm - 500 nm, which is a general description of the coating layer structure. It can be understood that the thickness of the primary particles in the stacking direction of the sheet structure is mainly 300 nm - 500 nm, and there are also a small number of thinner or thicker primary particles in the coating layer. Specifically, in the electron microscope photograph of the product, at least 40% or more of the primary particles have a thickness of 300 nm - 500 nm.

[0080] In one embodiment, the molecular general formula of the nickel-cobalt-manganese ternary precursor is Ni x Co y Mn z (OH)2, where x + y + z = 1, and 0.8 ≤ x ≤ 0.9, 0 < y ≤ 0.2, 0 < z ≤ 0.2. By increasing the nickel content of the nickel-cobalt-manganese ternary precursor with an ultra-low specific surface area, it is beneficial to simultaneously increase the specific capacity and cycling performance of the prepared cathode material.

[0081] The present application provides a preparation method for a nickel-cobalt-manganese ternary precursor, comprising the following steps:

[0082] S1, preparing a mixed metal salt solution by using soluble nickel salts, cobalt salts and manganese salts, and preparing a bottom solution by using first ammonia water, first alkali solution and water;

[0083] S2, adding the mixed metal salt solution, second ammonia water and second alkali solution to the bottom solution for coprecipitation reaction. When the D 50 particle size of the product reaches the target size, the reaction is completed to obtain a nickel-cobalt-manganese ternary precursor;

[0084] Among them, the coprecipitation reaction in step S2 includes a first reaction stage, a second reaction stage and a third reaction stage, and satisfies the following conditions:

[0085] (1) The pH value of the second reaction stage is less than the pH value of the first reaction stage, and the pH value of the third reaction stage is less than the pH value of the first reaction stage;

[0086] (2) The stirring speed starts to decrease gradually with the increase of the particle size of the product from the third reaction stage.

[0087] This application uses time-segmented, coordinated control of the pH value of the reaction solution and the stirring speed during the reaction process. On the one hand, this allows the reaction particles to grow slowly, thereby reducing the core volume of the precursor and increasing the thickness and density of the coating layer, forming a loose-inside-and-dense-outside structure. On the other hand, this allows the reaction particles to be highly dispersed, so that as the synthesis time increases, the primary particles grow radially, which is beneficial for maintaining the uniformity of the precursor. In addition, during the synthesis process, the stirring speed is gradually reduced according to the particle size, which can also avoid the phenomenon of particle breakage caused by stirring, thereby improving the quality of the obtained precursor.

[0088] In one embodiment, the coprecipitation reaction satisfies at least one of the following conditions:

[0089] (1) The pH value of the third reaction stage is less than or equal to the pH value of the second reaction stage;

[0090] (2) the stirring speed of the first reaction stage is greater than or equal to the stirring speed of the second reaction stage;

[0091] (3) the flow rate of the mixed metal salt solution increases from the second reaction stage, and the flow rate of the mixed metal salt solution in the first reaction stage is less than the flow rate of the mixed metal salt solution in the third reaction stage;

[0092] (4) The ammonia value in the first reaction stage is greater than or equal to the ammonia value in the second reaction stage, and the ammonia value in the second reaction stage is greater than or equal to the ammonia value in the third reaction stage;

[0093] (5) The first reaction stage, the second reaction stage and the third reaction stage are all carried out under alkaline conditions.

[0094] In one embodiment, the coprecipitation reaction satisfies at least one of the following conditions:

[0095] (1) The difference between the pH value of the first reaction stage and the pH value of the second reaction stage is 0.3-0.5, and the pH value of the third reaction stage is equal to the pH value of the second reaction stage;

[0096] (2) In the third reaction stage, the stirring speed is controlled to decrease by 20 rpm to 30 rpm for every 0.5 μm to 1 μm increase in the particle size of the product, and the stirring speed in the first reaction stage is equal to the stirring speed in the second reaction stage;

[0097] (3) the difference between the flow rate of the mixed metal salt solution in the second reaction stage and the flow rate of the mixed metal salt solution in the first reaction stage is less than or equal to 15 L / h, the increase rate is less than or equal to 1.3 L / h, and the flow rate of the mixed metal salt solution in the third reaction stage is equal to the flow rate of the mixed metal salt solution at the end of the second reaction stage;

[0098] (4) The ammonia value in the second reaction stage is equal to the ammonia value in the third reaction stage.

[0099] Based on the selective time-phased regulation of pH value and stirring speed, the present application limits the pH value difference, stirring speed difference, and flow rate difference and increase rate of the mixed metal salt solution in the first reaction stage, the second reaction stage, and the third reaction stage, thereby further improving the dispersion of the precursor while reducing the specific surface area.

[0100] It should be noted that the present application does not impose any restriction on the time point for increasing the flow rate of the mixed metal salt solution in the second reaction stage, that is, the flow rate of the mixed metal salt solution can be increased at any time point during the reaction process of the second reaction stage.

[0101] In one embodiment, the coprecipitation reaction further satisfies at least one of the following conditions:

[0102] (1) The pH value of the first reaction stage is 11.3-12.6, more preferably 11.5-12.4, the ammonia value is 2.0 g / L-10.0 g / L, more preferably 4.0 g / L-9.0 g / L, the stirring speed is 330 rpm-600 rpm, more preferably 360 rpm-550 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-30 L / h, more preferably 5 L / h-25 L / h;

[0103] (2) The pH value of the second reaction stage is 11.1-12.2, more preferably 11.3-12.0, the ammonia value is 2.0 g / L-10.0 g / L, more preferably 4.0 g / L-9.0 g / L, the stirring speed is 330 rpm-600 rpm, more preferably 360 rpm-550 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-40 L / h, more preferably 5 L / h-25 L / h;

[0104] (3) The pH value of the third reaction stage is 11.1-12.2, more preferably 11.3-12.0, the ammonia value is 2.0 g / L-10.0 g / L, more preferably 4.0 g / L-9.0 g / L, the stirring speed is 100 rpm-550 rpm, more preferably 200 rpm-520 rpm, and the flow rate of the mixed metal salt solution is 15 L / h-40 L / h, more preferably 15 L / h-35 L / h.

[0105] By selecting the range of pH value, ammonia value, stirring speed and flow rate of mixed metal salt solution, it is not only beneficial to reduce the agglomeration of the core and thus reduce the particle size of the precursor, but also to make the coating layer structure denser, which is conducive to forming a structure that is loose inside and dense outside, while improving the dispersibility and further reducing the specific surface area of ​​the precursor.

[0106] Preferably, the time of the first reaction stage accounts for 0.5%-1.5% of the total coprecipitation reaction time, more preferably 0.6%-1.0%, and the time of the second reaction stage accounts for 16%-25% of the total coprecipitation reaction time, more preferably 17%-23%. By controlling the reaction time of each reaction stage, the specific surface area of ​​the precursor is further reduced.

[0107] Since the traditional nickel-cobalt-manganese ternary precursor has a large specific surface area, resulting in strong surface activity, the particles are very easy to agglomerate to form large particles. However, the present application strictly controls the size and dispersibility of the reaction particles by regulating the pH value and stirring speed in the reaction stage. Therefore, the preparation method of the present application can prepare a nickel-cobalt-manganese ternary precursor with an ultra-low specific surface area and a target particle size of small particles.

[0108] During the coprecipitation reaction, the temperature is controlled at 40°C-75°C, more preferably 50°C-65°C, so as to obtain a nickel-cobalt-manganese ternary precursor with a better particle size.

[0109] In one embodiment, nitrogen is introduced into the coprecipitation reaction liquid at a flow rate of 100 L / h-800 L / h, preferably 150 L / h-700 L / h, and / or air is introduced at a flow rate of less than or equal to 300 L / h, preferably less than or equal to 100 L / h, which is beneficial to controlling the porosity of the particles and maintaining the dispersion of the particles and the thickness of the primary particles on the surface.

[0110] In one embodiment, the mixed metal salt solution in step S1 satisfies at least one of the following conditions:

[0111] (1) The total concentration of the mixed metal salt in the mixed metal salt solution is 1.2 mol / L-2.7 mol / L;

[0112] (2) Based on the total molar percentage of metal ions in the mixed metal salt solution as 100%, the molar percentage of nickel ions in the mixed metal salt solution is 80%-90%, the molar percentage of cobalt ions is less than or equal to 20%, and the molar percentage of manganese ions is less than or equal to 20%.

[0113] In one embodiment, the base solution in step S1 satisfies at least one of the following conditions:

[0114] (1) an ammonia value of 2 g / L to 10 g / L, more preferably 4.0 g / L to 9.0 g / L;

[0115] (2) pH value is 11.3-12.6, more preferably 11.5-12.4;

[0116] (3) The amount of water used is 100L-300L, more preferably 150L-270L;

[0117] (4) The concentration of the first ammonia solution is 1.0 mol / L-12.0 mol / L;

[0118] (5) the concentration of the first alkali solution is 1.0 mol / L-13.0 mol / L;

[0119] (6) The first alkali solution is a sodium hydroxide solution.

[0120] In one embodiment, the concentration of the second aqueous ammonia is 1.0 mol / L-12.0 mol / L, the concentration of the second alkali solution is 1.0 mol / L-13.0 mol / L, and the second alkali solution is sodium hydroxide solution.

[0121] It should be noted that the concentration of the second ammonia solution may be the same as or different from the concentration of the first ammonia solution, and the concentration of the second alkali solution may be the same as or different from the concentration of the first alkali solution, which is not limited in this application.

[0122] Wherein, the first alkali solution and / or the second alkali solution include but are not limited to sodium hydroxide solution, preferably sodium hydroxide solution.

[0123] In one embodiment, the coprecipitation reaction further includes the steps of aging, separation, washing, drying, screening and demagnetization.

[0124] The present application provides a positive electrode material made from the nickel-cobalt-manganese ternary precursor as described above.

[0125] The nickel-cobalt-manganese ternary precursor described in this application is used to prepare positive electrode materials, which can not only significantly reduce the amount of residual lithium on the surface of the positive electrode material, effectively reduce the specific surface area of ​​the positive electrode material, and reduce the side reactions with the electrolyte during the positive electrode charging and discharging process, but also improve the lithium-nickel mixing phenomenon during the sintering process, reduce the generation of quasi-single crystals, and enable the positive electrode material to have excellent electrochemical properties such as high energy density and long cycle life.

[0126] It should be noted that the preparation method of the positive electrode material refers to the existing method, and this application will not go into details.

[0127] The present application also provides a lithium-ion battery comprising the positive electrode material as described above.

[0128] Specifically, the lithium-ion battery includes a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, wherein the positive electrode sheet includes a positive electrode collector and a positive electrode material layer arranged on the surface of the positive electrode collector, and the positive electrode material layer includes the positive electrode material described above.

[0129] In one embodiment, the positive electrode material layer further includes a conductive agent and a binder.

[0130] Hereinafter, the nickel-cobalt-manganese ternary precursor and its preparation method and application will be further described through the following specific examples.

[0131] Example 1

[0132] Prepare a 10.5 mol / L sodium hydroxide solution as a precipitant, designated Solution A; prepare a 5 mol / L ammonia solution as a complexing agent, designated Solution B; and prepare a 2.3 mol / L mixed metal salt solution by mixing soluble nickel, cobalt, and manganese salts (at a molar ratio of 88:6:6) with deionized water, designated Solution C. Maintain a constant temperature of 25°C for Solutions A, B, and C.

[0133] A 500L titanium reactor with controllable temperature and speed was used. 250L of hot pure water was first added, the reactor temperature was controlled at 65°C, and the stirring speed was 360rpm. Solution A and solution B were then pumped into the reactor. The ammonia value was maintained at 7.5g / L before adding alkali, and the initial pH value was 12.30. This was used to prepare the reactor startup base solution. After the reaction began, the flow rates of solution A, solution B, and solution C were set to 7L / h, 2.5L / h, and 15L / h, respectively, and were continuously pumped into the 65°C constant temperature reactor through the feeding trough for reaction. At a stirring speed of 360rpm, the flow rate of solution A was adjusted to stabilize the pH value of the synthesis system at 12.30, and the flow rate of solution B was adjusted to maintain the ammonia value of the synthesis system at 5.0g / L. The nitrogen flow rate in the reactor atmosphere was adjusted to 500L / h and maintained for 60min to complete the first reaction stage.

[0134] At a stirring speed of 360 rpm, the flow rate of solution A was reduced, and the pH value was slowly adjusted to 11.80 and then restored. At the same time, the flow rate of solution B was synchronously adjusted to maintain the ammonia value of the synthesis system at 5.0 g / L. The nitrogen flow rate under the reaction kettle atmosphere was adjusted to 500 L / h for a duration of 33 hours. Among them, the flow rate of solution C was adjusted 15 hours after the completion of the first reaction stage, and was quickly increased to 25 L / h for 12 hours. The flow rates of solution A and solution B were synchronously adjusted to stabilize the pH value at 11.80 and maintain the ammonia value at 5.0 g / L. According to D 50 Reduce the stirring speed step by step to D 50 When it reaches 2.50 μm, the stirring speed is reduced and maintained at 340 rpm. 50When it reaches 3.20 μm, the stirring speed is reduced and maintained at 320 rpm. 50 When the particle size reaches 3.60 μm, the reaction is stopped to obtain a nickel-cobalt-manganese ternary precursor slurry.

[0135] The precursor slurry that meets the particle size requirements is discharged into a transfer tank and stirred. It is then washed alternately with alkaline and pure water. The material is then evenly distributed in a drying device and dried at 90°C for 8 hours. The nickel-cobalt-manganese ternary precursor product is then obtained through screening, iron removal, and packaging. The screen size is a double layer of 325 mesh. The morphology of the obtained nickel-cobalt-manganese ternary precursor is observed, as shown in Figure 1. The precursor has uniform particles and good dispersion, a small core particle size, and a thick and dense primary particle layer.

[0136] Example 2

[0137] Prepare a 10.5 mol / L sodium hydroxide solution as a precipitant, designated Solution A; prepare a 5 mol / L ammonia solution as a complexing agent, designated Solution B; and prepare a 2.3 mol / L mixed metal salt solution by mixing soluble nickel, cobalt, and manganese salts (in a molar ratio of 89:4:7) with deionized water, designated Solution C. Maintain a constant temperature of 25°C for Solutions A, B, and C.

[0138] A 500L titanium reactor with controllable temperature and speed was used. 250L of hot pure water was first added, the reactor temperature was controlled at 65°C, and the stirring speed was 400rpm. Then, solution A and solution B were pumped into the reactor. The ammonia value was maintained at 5.5g / L before adding alkali, and the initial pH value was 12.50. This was used to prepare the reactor startup bottom solution. After the reaction started, the flow rates of solution A, solution B, and solution C were set to 8L / h, 2.5L / h, and 15L / h, respectively, and were continuously pumped into the 65°C constant temperature reactor through the feeding trough for reaction. At a stirring speed of 360rpm, the flow rate of solution A was adjusted to stabilize the pH value of the synthesis system at 12.5, and the flow rate of solution B was adjusted to maintain the ammonia value of the synthesis system at 7.0g / L. The nitrogen flow rate in the reactor atmosphere was adjusted to 400L / h and maintained for 45min to complete the first reaction stage.

[0139] At a stirring speed of 400 rpm, the flow rate of solution A was reduced, and the pH value was slowly adjusted to 11.90 and then restored. At the same time, the flow rate of solution B was synchronously adjusted to maintain the ammonia value of the synthesis system at 7.0 g / L. The nitrogen flow rate under the reaction kettle atmosphere was adjusted to 400 L / h for 30 hours. Among them, the flow rate of solution C was adjusted 15 hours after the completion of the first reaction stage, and quickly increased to 30 L / h for 12 hours. The flow rates of solution A and solution B were synchronously adjusted to stabilize the pH value at 11.90 and maintain the ammonia value at 7.0 g / L. According to D 50Reduce the stirring speed step by step to D 50 When it reaches 2.50 μm, the stirring speed is reduced and maintained at 370 rpm. 50 When it reaches 3.50 μm, the stirring speed is reduced and maintained at 310 rpm. 50 When the particle size reaches 3.90 μm, the reaction is stopped to obtain a nickel-cobalt-manganese ternary precursor slurry.

[0140] The precursor slurry that meets the particle size requirements is discharged into a transfer tank and stirred. It is then washed alternately with alkali and pure water. The material is then evenly distributed in a drying device and dried at 90°C for 8 hours. The nickel-cobalt-manganese ternary precursor product is then obtained after screening, iron removal, and packaging. The screen size is a double layer of 325 mesh. The morphology of the prepared nickel-cobalt-manganese ternary precursor is observed, as shown in Figure 2. It can be seen that the precursor particles are uniform and well dispersed, with a small core particle size and a thick and dense primary particle layer.

[0141] Example 3

[0142] The same solution A, solution B, and solution C as in Example 2 were prepared.

[0143] A 500L titanium reactor with controllable temperature and speed was used. 250L of hot pure water was first added, the reactor temperature was controlled at 60°C, the stirring speed was 360rpm, and then solution A and solution B were pumped into the reactor. The ammonia value was maintained at 5.5g / L before adding alkali, and the initial pH value was 12.35, which was prepared as the reactor startup bottom liquid. After the reaction started, the flow rates of solution A, solution B, and solution C were set to 8L / h, 2.5L / h, and 15L / h, respectively, and they were continuously pumped into a constant temperature reactor at 60°C through a feeding trough for reaction. The subsequent steps were the same as in Example 2. The morphology of the obtained nickel-cobalt-manganese ternary precursor was observed. As shown in Figure 3, it can be seen that the precursor particles are uniform and well dispersed, the core particle size is small, and the thickness of the primary particle layer is high and dense.

[0144] Example 4

[0145] Configuration is identical with embodiment 2 solution A, solution B, solution C. Using temperature-controllable, speed-controllable 500L titanium reactor, first add hot pure water 250L, control reactor temperature is 60 ℃, stirring speed is 420rpm, then solution A and solution B are pumped into reactor, ammonia value is maintained at 4.5g / L before adding alkali, initial pH value is 12.10, be mixed with reactor startup bottom liquid. After starting reaction, the flow rate of solution A, solution B, solution C is set to 8L / h, 2.5L / h, 15L / h respectively, and is continuously pumped into 60 ℃ constant temperature reactor respectively through feeding trough for reaction. Under stirring speed 360rpm, the flow rate of regulating solution A makes the pH value of synthesis system be stabilized at 12.10, the flow rate of regulating solution B makes the ammonia value of synthesis system be maintained at 5.5g / L, regulates reactor atmosphere liquid nitrogen flow rate to be 400L / h, holding time 90min, completes the first reaction stage.

[0146] At a stirring speed of 420 rpm, the flow rate of solution A was reduced, and the pH value was slowly adjusted to 11.70 and then restored. At the same time, the flow rate of solution B was synchronously adjusted to maintain the ammonia value of the synthesis system at 4.5 g / L. The nitrogen flow rate under the reaction kettle atmosphere was adjusted to 400 L / h for 30 hours. Among them, the flow rate of solution C was adjusted 15 hours after the completion of the first reaction, and was quickly increased to 25 L / h for 12 hours. The flow rates of solution A and solution B were synchronously adjusted to stabilize the pH value at 11.70 and maintain the ammonia value at 4.5 g / L. According to D 50 Reduce the stirring speed step by step to D 50 When it reaches 2.50 μm, the stirring speed is reduced and maintained at 390 rpm. 50 When it reaches 3.50 μm, the stirring speed is reduced and maintained at 360 rpm. 50 When the particle size reaches 3.85 μm, the reaction is stopped to obtain a nickel-cobalt-manganese ternary precursor slurry.

[0147] The precursor slurry that meets the particle size requirements is discharged into a transfer tank and stirred. It is then washed alternately with alkali and pure water. The material is then evenly distributed in a drying device and dried at 90°C for 8 hours. The nickel-cobalt-manganese ternary precursor product is then obtained after screening, iron removal, and packaging. The screen size is a double layer of 325 mesh. The morphology of the prepared nickel-cobalt-manganese ternary precursor is observed, as shown in Figure 2. It can be seen that the precursor particles are uniform and well dispersed, with a small core particle size and a thick and dense primary particle layer.

[0148] Example 5

[0149] Configuration is identical with embodiment 2 solution A, solution B, solution C. Using temperature-controllable, speed-controllable 500L titanium reactor, first add hot pure water 250L, control reactor temperature is 70 ℃, stirring speed is 450rpm, then solution A and solution B are pumped into reactor, ammonia value is maintained at 4.0g / L before adding alkali, initial pH value is 12.00, be mixed with reactor startup bottom liquid. After starting reaction, the flow rate of solution A, solution B, solution C is set to 8L / h, 2.5L / h, 15L / h respectively, and is continuously pumped into 70 ℃ constant temperature reactor respectively through feeding trough for reaction. Under stirring speed 360rpm, the flow rate of solution A is regulated so that the pH value of synthesis system is stabilized at 12.00, the flow rate of solution B is regulated so that the ammonia value of synthesis system is maintained at 4.0g / L, and the nitrogen flow rate under regulating reactor atmosphere liquid is 400L / h, and holding time is 90min, completes the first reaction stage.

[0150] At a stirring speed of 450rpm, the flow rate of solution A was reduced, and the pH value was slowly adjusted to 11.70 and then restored. At the same time, the flow rate of solution B was synchronously adjusted to maintain the ammonia value of the synthesis system at 4.0g / L. The nitrogen flow rate under the liquid atmosphere of the reactor was adjusted to 400L / h for 35h. Among them, the flow rate of solution C was adjusted 15h after the completion of the first reaction, and quickly increased to 30L / h for 12h. The flow rates of solution A and solution B were synchronously adjusted to stabilize the pH value at 11.70 and maintain the ammonia value at 4.0g / L. According to D 50 Reduce the stirring speed step by step to D 50 When it reaches 2.50 μm, the stirring speed is reduced and maintained at 420 rpm. 50 When it reaches 3.50 μm, the stirring speed is reduced and maintained at 390 rpm. 50 When the particle size reaches 3.75 μm, the reaction is stopped to obtain a nickel-cobalt-manganese ternary precursor slurry.

[0151] The precursor slurry that meets the particle size requirements is discharged into a transfer tank and stirred. It is then washed alternately with alkali and pure water. The material is then evenly distributed in a drying device and dried at 90°C for 8 hours. The nickel-cobalt-manganese ternary precursor product is then obtained after screening, iron removal, and packaging. The screen size is a double layer of 325 mesh. The morphology of the prepared nickel-cobalt-manganese ternary precursor is observed, as shown in Figure 2. It can be seen that the precursor particles are uniform and well dispersed, with a small core particle size and a thick and dense primary particle layer.

[0152] Comparative Example 1

[0153] The difference between Comparative Example 1 and Example 2 is that the stirring speed in the first to third reaction stages is constant at 300 rpm.

[0154] The morphology of the prepared nickel-cobalt-manganese ternary precursor was observed. As shown in FIG4 , it can be seen that the precursor particles are partially agglomerated, the inner core porosity reaches 8%, and there are voids, resulting in a high BET.

[0155] Comparative Example 2

[0156] The difference between Comparative Example 2 and Example 2 is that the pH value of the second reaction stage is reduced to 11.0 and the duration is 2 hours.

[0157] The morphology of the prepared nickel-cobalt-manganese ternary precursor was observed. As shown in FIG5 , the surface of the precursor particles was stacked in thin sheets, and the surface and interior of the particles had abundant pores, resulting in a large specific surface area of ​​the particles.

[0158] Comparative Example 3

[0159] Step 1: According to the molar ratio of nickel, cobalt and manganese elements in the required nickel-cobalt-manganese hydroxide, that is, 9:0.5:0.5, soluble salts of nickel, cobalt and manganese are selected as raw materials, pure water is added to prepare a 1.2 mol / L mixed metal salt solution, a sodium hydroxide solution with a concentration of 1.0 mol / L is prepared, and ammonia water with a concentration of 1.0 mol / L is prepared as a complexing agent.

[0160] Step 2: Open the jacket of the reactor to allow water inlet and return, and introduce nitrogen into the reactor.

[0161] Step 3: add pure water to the reactor until it covers the bottom stirring paddle, then add the sodium hydroxide solution and ammonia water prepared in step 1 to form a reaction start-up bottom liquid, and keep nitrogen in the synthesis process; the pH value of the start-up bottom liquid is 11.2 (45°C) and the ammonia value is 1.0 g / L.

[0162] Step 4: The mixed metal salt solution, sodium hydroxide solution and ammonia water prepared in step 1 are added to the reactor in parallel under constant stirring for reaction. The amount of the mixed metal salt solution added per hour is 0.001 of the total volume of the reactor, and the stirring power per unit volume is controlled to be 10 W / L, the reaction temperature is controlled to be 50.0° C., the pH value is 11.2 (45° C.), and the ammonia value is 1.0 g / L.

[0163] Step 5: When the amount of seed crystals in the reactor reaches the target, lower the reaction pH to 10.8 (45°C), continue to control the reaction temperature to 50.0°C and the ammonia value to 1.0 g / L, and gradually increase the flow rate of the mixed metal salt solution in a linear manner within 1 hour to an amount added per hour of 0.01 of the total volume of the reactor, and then keep the flow rate of the mixed metal salt solution stable.

[0164] Step 6: When the liquid level reaches the clearing requirement, start the concentrator to start clearing, maintain the liquid level in the reactor stable, gradually increase the solid content in the reactor, and start to continuously introduce air or oxygen, with the ratio of the introduction amount to nitrogen being 0.01:1.

[0165] Step 7: After the solid content in the reactor reaches 50 g / L, the temperature is gradually lowered to 40.0°C, the pH is 10.4 (45°C), and the stirring power per unit volume is 0.2 W / L in a linear manner. After that, the mixture is kept stable and the ammonia value is continued to be controlled at 1.0 g / L.

[0166] Step 8: When it is detected that the particle size of the material in the reactor reaches the required requirement, the feeding of the reactor is stopped, and stirring and aging are continued for 1-2 hours.

[0167] Step 9: performing solid-liquid separation on the aged material in step 8, washing the separated filter cake with potassium hydroxide or sodium hydroxide solution, and then rinsing with pure water to obtain a washed filter cake.

[0168] Step 10: drying the filter cake washed in step 9 with a drying device, and then screening and demagnetizing the filter cake to obtain large particles of nickel-cobalt-manganese hydroxide.

[0169] The large-particle nickel-cobalt-manganese hydroxide prepared in this comparative example was determined to be spherical particles by scanning electron microscopy, and D was determined by laser particle size analysis and diffraction. 50 The particle size is 9.80 μm. As shown in Figure 6, the particles exhibit radial growth. A cross-section image taken through the particle by an argon ion beam reveals a loose and porous internal structure. The primary particles are clearly textured, elongated strips with a width of 30 nm to 250 nm.

[0170] Examples 1-5 and Comparative Examples 1-3 were tested, and the results are shown in Table 1 and Table 2.

[0171] Table 1

[0172] Table 2

[0173] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0174] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art could make various modifications and improvements without departing from the spirit of the present application, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A nickel-cobalt-manganese ternary precursor, characterized in that: It includes an inner core and a coating layer formed by stacking a plurality of primary particles on the inner core surface, wherein the porosity of the inner core is greater than the porosity of the coating layer, the particle size of the inner core is less than or equal to 1 μm, and the ratio of the radius of the inner core to the thickness of the coating layer is less than or equal to 1:2.

75.

2. The nickel-cobalt-manganese ternary precursor according to claim 1, characterized in that: The nickel-cobalt-manganese ternary precursor satisfies at least one of the following conditions: (1) The volume of the inner core accounts for 0.5%-4.0% of the volume of the nickel-cobalt-manganese ternary precursor; (2) The particle size of the nickel-cobalt-manganese ternary precursor is less than or equal to 8 μm; (3) The porosity of the coating layer is less than or equal to 1.5%; (4) The porosity of the inner core is 1%-5%; (5) K of the nickel-cobalt-manganese ternary precursor 90 It is 0.50-0.

55.

3. The nickel-cobalt-manganese ternary precursor according to claim 2, characterized in that: The particle size of the nickel-cobalt-manganese ternary precursor is 3 μm-8 μm.

4. The nickel-cobalt-manganese ternary precursor according to any one of claims 1 to 3, characterized in that: The primary particles are obtained by stacking a plurality of sheet-like structures, and the thickness of the primary particles in the stacking direction of the sheet-like structures is 300nm-500nm.

5. The nickel-cobalt-manganese ternary precursor according to any one of claims 1 to 3, characterized in that: The molecular formula of the nickel-cobalt-manganese ternary precursor is Ni x Co y Mn z (OH)2, where x+y+z=1, and 0.8≤x≤0.9, 0 <y≤0.2,0<z≤0.2。 6. A method for preparing a nickel-cobalt-manganese ternary precursor according to any one of claims 1 to 5, characterized in that: The steps include: A mixed metal salt solution is prepared by using soluble nickel salt, cobalt salt and manganese salt, and a base solution is prepared by using a first ammonia solution, a first alkali solution and water; The mixed metal salt solution, the second ammonia solution and the second alkali solution are continuously added to the base solution for coprecipitation reaction, and when the D50 particle size of the product reaches the target size, the reaction is completed to obtain a nickel-cobalt-manganese ternary precursor; Wherein, the coprecipitation reaction includes a first reaction stage, a second reaction stage and a third reaction stage, and meets the following conditions: (1) The pH value of the second reaction stage is lower than the pH value of the first reaction stage, and the pH value of the third reaction stage is lower than the pH value of the first reaction stage; (2) Starting from the third reaction stage, the stirring speed decreases gradually as the product particle size increases.

7. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 6, characterized in that: The coprecipitation reaction satisfies at least one of the following conditions: (1) The pH value of the third reaction stage is less than or equal to the pH value of the second reaction stage; (2) the stirring speed of the first reaction stage is greater than or equal to the stirring speed of the second reaction stage; (3) the flow rate of the mixed metal salt solution increases from the second reaction stage, and the flow rate of the mixed metal salt solution in the first reaction stage is less than the flow rate of the mixed metal salt solution in the third reaction stage; (4) the ammonia value of the first reaction stage is greater than or equal to the ammonia value of the second reaction stage, and the ammonia value of the second reaction stage is greater than or equal to the ammonia value of the third reaction stage; (5) The first reaction stage, the second reaction stage and the third reaction stage are all carried out under alkaline conditions.

8. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 7, characterized in that: The coprecipitation reaction satisfies at least one of the following conditions: (1) The difference between the pH value of the first reaction stage and the pH value of the second reaction stage is 0.3-0.5, and the pH value of the third reaction stage is equal to the pH value of the second reaction stage; (2) In the third reaction stage, the stirring speed is controlled to decrease by 20 rpm to 30 rpm for every 0.5 μm to 1 μm increase in the particle size of the product, and the stirring speed in the first reaction stage is equal to the stirring speed in the second reaction stage; (3) the difference between the flow rate of the mixed metal salt solution in the second reaction stage and the flow rate of the mixed metal salt solution in the first reaction stage is less than or equal to 15 L / h, the lifting rate is less than or equal to 1.3 L / h, and the flow rate of the mixed metal salt solution in the third reaction stage is equal to the flow rate of the mixed metal salt solution at the end of the second reaction stage; (4) The ammonia value in the second reaction stage is equal to the ammonia value in the third reaction stage.

9. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 8, characterized in that: The coprecipitation reaction also satisfies at least one of the following conditions: (1) The pH value of the first reaction stage is 11.3-12.6, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 330 rpm-600 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-30 L / h; (2) The pH value of the second reaction stage is 11.1-12.2, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 330 rpm-600 rpm, and the flow rate of the mixed metal salt solution is 2 L / h-40 L / h; (3) The pH value of the third reaction stage is 11.1-12.2, the ammonia value is 2.0 g / L-10.0 g / L, the stirring speed is 100 rpm-550 rpm, and the flow rate of the mixed metal salt solution is 15 L / h-40 L / h.

10. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 6, characterized in that: The time of the first reaction stage accounts for 0.5%-1.5% of the total coprecipitation reaction time, and the time of the second reaction stage accounts for 16%-25% of the total coprecipitation reaction time.

11. The method for preparing a nickel-cobalt-manganese ternary precursor according to any one of claims 6 to 10, characterized in that: The coprecipitation reaction also satisfies at least one of the following conditions: (1) The flow rate of submerged nitrogen into the reaction liquid is 100 L / h-800 L / h; (2) The flow rate of submerged air introduced into the reaction liquid is less than or equal to 300 L / h; (3) The reaction temperature is 40°C-75°C; (4) The concentration of the second aqueous ammonia is 1.0 mol / L-12.0 mol / L; (5) the concentration of the second alkali solution is 1.0 mol / L-13.0 mol / L; (6) The second alkaline solution is a sodium hydroxide solution.

12. The method for preparing the nickel-cobalt-manganese ternary precursor according to any one of claims 6 to 10, characterized in that: The mixed metal salt solution satisfies at least one of the following conditions: (1) The total concentration of the mixed metal salt in the mixed metal salt solution is 1.2 mol / L-2.7 mol / L; (2) Taking the total molar percentage of metal ions in the mixed metal salt solution as 100%, the molar percentage of nickel ions in the mixed metal salt solution is 80%-90%, the molar percentage of cobalt ions is less than or equal to 20%, and the molar percentage of manganese ions is less than or equal to 20%.

13. The method for preparing a nickel-cobalt-manganese ternary precursor according to any one of claims 6 to 10, characterized in that: The base liquid satisfies at least one of the following conditions: (1) Ammonia value is 2g / L-10g / L; (2) pH value is 11.3-12.6; (3) The amount of water used is 100L-300L; (4) The concentration of the first aqueous ammonia is 1.0 mol / L-12.0 mol / L; (5) the concentration of the first alkali solution is 1.0 mol / L-13.0 mol / L; (6) The first alkali solution is a sodium hydroxide solution.

14. A positive electrode material made from the nickel-cobalt-manganese ternary precursor according to any one of claims 1 to 5.

15. A lithium ion battery, characterized in that: Comprising the positive electrode material as claimed in claim 14.

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