阅读说明：本技术 一种高镍单晶正极材料及其前驱体、以及前驱体的制备方法 (High-nickel single crystal positive electrode material, precursor thereof and preparation method of precursor ) 是由 李玉云 张海艳 胡志兵 刘庭杰 胡海诗 吴泽盈 刘凯 熊意球 刘宙 张娉婷 黎力 于 2021-09-28 设计创作，主要内容包括：本发明属于锂离子电池材料技术领域,具体公开了一种高镍单晶正极材料的前驱体的制备方法。通过控制各反应溶液的通入流量满足如下公式：106<<153,其中,A-(上清液碱度)为反应体系的上清液的碱度值,单位为g/L,通过酸碱滴定确定；V-(盐)为镍钴锰混合盐溶液的流量,V-(碱)为沉淀剂溶液的流量,V-(氨)为络合剂溶液的流量,单位均为mL/min,制备得到高镍单晶正极材料的前驱体。该制备方法流程简单、可实现连续化高效生产、成本低,具有广泛的应用市场。(The invention belongs to the technical field of lithium ion battery materials, and particularly discloses a preparation method of a precursor of a high-nickel single crystal cathode material. The following formula is satisfied by controlling the flow rate of each reaction solution: 106< <153 wherein A Alkalinity of supernatant The alkalinity value of the supernatant of the reaction system is g/L and is determined by acid-base titration; v Salt (salt) Is the flow of the mixed salt solution of nickel, cobalt and manganese, V Alkali Is the flow rate of the precipitant solution, V Ammonia The flow of the complexing agent solution is mL/min, and the precursor of the high-nickel monocrystal anode material is prepared. The preparation method has the advantages of simple process, continuous and efficient production, low cost and wide application market.)

1. A preparation method of a precursor of a high-nickel single-crystal positive electrode material is characterized by comprising the following steps of:

step (1), according to the chemical molecular formula Ni_xCo_yMn_1-x-y(OH)₂Preparing a nickel-cobalt-manganese mixed salt solution, wherein x is more than 0.5 and less than 0.8, and y is more than 0 and less than or equal to 0.1; preparing a complexing agent solution and a precipitator solution;

step (2), preparing a reaction kettle bottom liquid;

and (3) adding a nickel-cobalt-manganese mixed salt solution, a complexing agent solution and a precipitator solution into the bottom solution of the reaction kettle in a parallel flow manner to perform a coprecipitation reaction, wherein the coprecipitation reaction satisfies the following formula:

106<<153 wherein A_{Alkalinity of supernatant}The alkalinity value of the supernatant of the reaction system is g/L and is determined by acid-base titration; v_{Salt (salt)}Is the flow of the mixed salt solution of nickel, cobalt and manganese, V_AlkaliIs the flow rate of the precipitant solution, V_AmmoniaThe unit is the flow of the complexing agent solution and is ml/min;

the coprecipitation reaction is carried out in a nitrogen atmosphere;

and (4) after the granularity of the slurry of the reaction system is stable, collecting the slurry overflowing from the overflow port of the reaction kettle by a slurry tank, then carrying out solid-liquid separation, and carrying out aging, washing, drying and screening treatment on the separated solid phase to obtain the precursor of the high-nickel single crystal cathode material.

2. The method according to claim 1, wherein the concentration of the total metal ions in the nickel-cobalt-manganese mixed salt solution in step (1) is 2-3mol/L, and the concentration of the complexing agent solution is 106-114 g/L.

3. The method according to claim 1, wherein the reaction kettle bottom solution in the step (2) is a mixed solution of sodium hydroxide and ammonia water.

4. The process according to claim 3, wherein the temperature of the bottom liquid in the reaction vessel is 55 to 75 ℃, the alkalinity is 2g/l to 8g/l, and the pH value is 11.0 to 12.0.

5. The method according to claim 1, wherein in the co-precipitation reaction process in step (3), the reaction temperature is 55-75 ℃, the alkalinity of the supernatant is 2-8 g/l, the solid content is 80-160 g/l, the pH value is 11.0-12.0, and the stirring speed is 200-600 r/min.

6. The method according to claim 1, wherein the drying process of step (4) has the following parameters: the drying temperature is 110-180 ℃, and the drying time is 8-18 h.

7. A precursor of a high-nickel single-crystal anode material is characterized in that primary particles of the anode material are rectangular thick sheets with the average thickness of 200-300nm, and the primary particles are superposed into spheroidal secondary particles; ratio of specific surface area to tap Density SSA/TD<5×10⁴cm⁵/g²。

8. A high-nickel single-crystal positive electrode material, which is obtained by calcining a precursor prepared by the preparation method according to any one of claims 1 to 6 or the precursor mixed with lithium according to claim 7.

Technical Field

The invention belongs to the technical field of lithium ion battery materials, and particularly relates to a high-nickel single crystal positive electrode material, a precursor thereof and a preparation method of the precursor.

Background

The precursor directly determines the core physical and chemical properties of the anode material and is the key for producing the anode material. The key to influence the performance of the precursor is the proportion of each metal element in the precursor. In the ternary precursor, the nickel, cobalt and manganese elements are classified into NCM111, NCM442, NCM523, NCM622, NCM811 and the like according to the proportion of the nickel element from low to high. The high-nickel ternary material has theoretical high energy density and is the key point of the development of the ternary material at the present stage. Furthermore, the single crystallization of ternary materials is also an important trend.

Patent document CN112158889A discloses a method for mass production of single crystal cobalt-free lithium-rich manganese-based binary material precursor, wherein the stirring speed, temperature and feed flow of each raw material are strictly controlled during the production process, and a reducing agent is added to prevent oxidation of Mn. The method has complex process and difficult parameter control.

Patent document No. CN112768682A discloses a method for preparing a plate-like high-nickel single crystal ternary material, wherein an additive solution containing a surfactant is additionally added in the process of synthesizing a precursor, thereby increasing the cost of raw materials.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a preparation method of a precursor of a high-nickel single-crystal cathode material. The preparation method has the advantages of simple process, low cost and stable product quality.

In order to achieve the above object, the present invention adopts the following technical solutions.

The preparation method of the precursor of the high-nickel single crystal cathode material adopts a continuous method and comprises the following steps:

step (1), according to the chemical molecular formula Ni_xCo_yMn_1-x-y(OH)₂Preparing a nickel-cobalt-manganese mixed salt solution, wherein x is more than 0.5 and less than 0.8, and y is more than 0 and less than or equal to 0.1; preparing complexing agent solution and precipitant solution.

And (2) preparing a reaction kettle bottom liquid.

And (3) adding a nickel-cobalt-manganese mixed salt solution, a complexing agent solution and a precipitator solution into the bottom liquid of the reaction kettle in a parallel flow manner, and carrying out coprecipitation reaction. The reaction process was carried out under nitrogen atmosphere.

In this step, the flow rate of each solution in the reaction system satisfies the following formula:

106<<153 wherein A_{Alkalinity of supernatant}The alkalinity value of the supernatant of the reaction system is g/L and is determined by acid-base titration; v_{Salt (salt)}Is the flow of the mixed salt solution of nickel, cobalt and manganese, V_AlkaliIs the flow rate of the precipitant solution, V_AmmoniaThe unit is the flow of the complexing agent solution and is ml/min.

And (4) after the granularity of the slurry of the reaction system is stable, collecting the slurry overflowing from the overflow port of the reaction kettle by a slurry tank, then carrying out solid-liquid separation, and carrying out aging, washing, drying and screening treatment on the separated solid phase to obtain the precursor of the high-nickel single crystal cathode material.

Further, in the above preparation method, the concentration of the total metal ions in the nickel-cobalt-manganese mixed salt solution in the step (1) is 2-3mol/L, and the concentration of the complexing agent solution is 106-114 g/L.

Further, in the above preparation method, the reaction kettle base solution in step (2) is a mixed solution of sodium hydroxide and ammonia water. The temperature of the bottom liquid of the reaction kettle is 55-75 ℃, the alkalinity is 2-8 g/l, and the pH value is 11.0-12.0.

Further, in the preparation method, the coprecipitation reaction in the step (3) is carried out at a reaction temperature of 55-75 ℃, the alkalinity of the supernatant is 2-8 g/l, the solid matter content is 80-160 g/l, the pH value is 11.0-12.0, and the stirring speed is 200-600 r/min.

Further, in the above preparation method, the parameters of the drying process in step (4) are as follows: the drying temperature is 110-180 ℃, and the drying time is 8-18 h.

Furthermore, the primary particles of the precursor of the high-nickel single crystal cathode material obtained by the preparation method are rectangular thick plates with the average thickness within the range of 200-300nm, and the primary particles are superposed to form spheroidal secondary particles.

Further, the ratio SSA/TD of the specific surface area to the tap density of the precursor of the high-nickel single-crystal cathode material<5×10⁴cm⁵/g²。SSA/TD<5×10⁴cm⁵/g²The powder of the anode material obtained after the precursor is calcined is soft, the abrasion of the crushing to equipment is small, the micro powder is less, and the method is very suitable for industrial production.

In addition, based on the same inventive concept, the invention provides a high-nickel single-crystal cathode material which is obtained by calcining the precursor mixed lithium prepared by the preparation method.

In the continuous preparation process, when the calculated A is less than or equal to 106, the NH consumption caused by the complexation reaction in the reaction kettle after feeding is indicated₃ ^.H₂0, therefore, a larger ammonia water flow is needed to be provided at the initial stage of slotting to ensure the alkalinity of the supernatant to be stable, when the calculated A is more than or equal to 153, the primary particles are relatively fine and uneven, and the appearance that the primary particles are uniformly thick and densely arranged cannot be obtained because of the specific rangeThe values are conditions for forming a uniform thick sheet overlying a densely arranged topography.

Compared with the prior art, the invention has the following beneficial effects:

the precursor of the high-nickel single crystal anode material is prepared by controlling the flow of each reaction solution. The preparation method has the advantages of simple process, continuous and efficient production, low cost and wide application market.

The precursor product prepared by the invention is processed into the single crystal anode material with soft powder, the grinding has little abrasion to equipment, the micro powder is less, the prepared anode material has high cycle performance, the use amount of cobalt is reduced, and the production cost is greatly reduced.

Drawings

FIG. 1 shows a precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM images at high magnification.

FIG. 2 shows a precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM images under low magnification.

FIG. 3 shows a precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂XRD spectrum of (1).

FIG. 4 shows a precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM image of single crystal cathode material obtained by lithium mixing and sintering.

FIG. 5 shows a precursor Ni prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM images at high magnification.

FIG. 6 shows a precursor Ni prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM images at low magnification.

FIG. 7 shows a precursor Ni prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂XRD spectrum of (1).

FIG. 8 shows a precursor Ni prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM image of single crystal cathode material obtained by lithium mixing and sintering.

FIG. 9 shows a precursor Ni prepared in example 3 of the present invention_0.6Co_0.1Mn_0.3(OH)₂SEM images at high magnification.

FIG. 10 shows a precursor Ni prepared in example 3 of the present invention_0.6Co_0.1Mn_0.3(OH)₂SEM images at low magnification.

FIG. 11 shows a precursor Ni prepared in example 3 of the present invention_0.6Co_0.1Mn_0.3(OH)₂XRD spectrum of (1).

FIG. 12 shows a precursor Ni prepared in comparative example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM images at high magnification.

FIG. 13 shows a precursor Ni prepared in comparative example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM images under low magnification.

FIG. 14 shows a precursor Ni prepared in comparative example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂XRD spectrum of (1).

FIG. 15 shows a precursor Ni prepared in comparative example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM images at high magnification.

FIG. 16 shows a precursor Ni prepared in comparative example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM images under low magnification.

FIG. 17 shows a precursor Ni prepared in comparative example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂XRD spectrum of (1).

Detailed Description

The present invention will now be described in detail with reference to the drawings, which are given by way of illustration and explanation only and should not be construed to limit the scope of the present invention in any way.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the invention pertains.

Example 1:

the embodiment comprises the following steps:

(1) preparing a nickel-cobalt-manganese mixed salt solution with the total metal ion concentration of 2mol/L according to the molar ratio of nickel, cobalt and manganese of 58:7:35, preparing a sodium hydroxide solution as a precipitator solution, and preparing an ammonia water solution with the concentration of 106 g/L-114 g/L as a complexing agent solution.

(2) And continuously introducing nitrogen into a 100L reaction kettle, and adding deionized water, a sodium hydroxide solution and an ammonia water solution to prepare a reaction kettle bottom solution. The temperature of the bottom liquid of the reaction kettle is 72.5 ℃, the initial alkalinity of the bottom liquid is controlled at 5g/l, and the pH value is 11.2.

(3) The reaction kettle is started to stir at the stirring speed of 500 r/min; then the mixed salt solution of nickel, cobalt and manganese, the sodium hydroxide solution and the ammonia water solution are introduced in parallel to carry out continuous coprecipitation reaction. During the reaction, the temperature of the reaction system was maintained at 72.5 ℃ and A was maintained_{Alkalinity of supernatant}V flowing into the reaction kettle at 5g/l_{Salt (salt)}+V_Alkali+V_AmmoniaThe total flow rate of (a) is 105ml/min,and =125, the pH value of the reaction system is 11.0-11.5, and the solid matter content in the reaction system is controlled to be 150 g/l.

(4) After the slurry particle size of the reaction system is stable, the slurry tank collects slurry overflowing from the overflow port of the reaction kettle, solid-liquid separation is carried out after the weight of the slurry collected in the slurry tank reaches the required sample weight, solid materials are retained, aging, circulation, washing, drying at 120 ℃ for 15 hours and screening are carried out, and the precursor Ni of the high-nickel single crystal anode material with the nickel-cobalt-manganese metal ion molar content ratio of 58:7:35 is obtained_0.58Co_0.07Mn_0.35(OH)₂。

FIG. 1 and FIG. 2 show the precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂SEM picture of (1), from which it can be seen that the precursor Ni_0.58Co_0.07Mn_0.35(OH)₂The primary particles are rectangular thick sheets, and the primary particles are tightly packed into sphere-like secondary particlesThe dispersibility of the particles and the secondary particles is better.

FIG. 3 shows a precursor Ni prepared in example 1 of the present invention_0.58Co_0.07Mn_0.35(OH)₂The XRD pattern of the precursor is complete and has no any impurity peak.

Further detecting other physical and chemical indexes of the precursor to obtain the precursor with SSA of 5.96 m²(g), TD is 2.12g/m³D50 is 4.33. mu.m.

Precursor Ni prepared in the embodiment 1 of the invention_0.58Co_0.07Mn_0.35(OH)₂And mixing the lithium ion battery with lithium and calcining to obtain the cathode material. Fig. 4 is an SEM image of the produced positive electrode material, and it can be seen from the image that the positive electrode material contains a small amount of fine powder.

Example 2

The general idea for preparing the product was the same as in example 1, except that the main components and the reaction temperature were different, and this example included the following steps:

(1) nickel, cobalt and manganese are mixed according to the metal ion molar ratio of 65:7:28, preparing a mixed metal salt solution with the total ion concentration of 2mol/L, wherein the precipitator is a sodium hydroxide solution, the complexing agent is ammonia water, and the gram-liter concentration of the ammonia water is 106-114 g/L.

(2) Adding deionized water into 100L of reaction kettle bottom liquid, continuously introducing nitrogen, controlling the stirring speed at 500r/min, heating to 65 ℃, introducing ammonia water and sodium hydroxide solution, and preparing the bottom liquid, wherein the initial alkalinity of the bottom liquid is controlled at 5g/L, and the pH value is controlled at 11.2;

(3) after the initial system is stable, mixed salt solution, precipitator and complexing agent are introduced into the reaction kettle with base solution in parallel flow, continuous coprecipitation reaction is carried out, the temperature of the reaction system is stabilized at 65 ℃, and A is kept_{Alkalinity of supernatant}V is 5g/l and flows into the reaction kettle in unit time_{Salt (salt)}+V_Alkali+V_AmmoniaThe total volume of the mixed solution is 110ml/min,=130, the pH value of the reaction system is 11.0-11.5, and the reactantThe solid content in the system is controlled at 130 g/l.

(4) After the granularity of the slurry of the reaction system is stable, the slurry tank collects the slurry overflowing from the overflow port of the reaction kettle, after the weight of the slurry collected in the slurry tank reaches the required sample weight, solid-liquid separation is carried out, solid materials are reserved, and after aging, circulation, washing, drying at 120 ℃ for 15 hours and screening, the molar content ratio of nickel, cobalt and manganese metal ions is 65:7: precursor Ni of 28 high-nickel single crystal anode material_0.65Co_0.07Mn_0.28(OH)₂。

FIGS. 5 and 6 show Ni precursors prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂SEM picture of (1), from which it can be seen that the precursor Ni_0.65Co_0.07Mn_0.28(OH)₂The primary particles are rectangular thick sheets, the primary particles are tightly packed into sphere-like secondary particles, and the dispersibility of the secondary particles is better.

FIG. 7 shows a precursor Ni prepared in example 2 of the present invention_0.65Co_0.07Mn_0.28(OH)₂The XRD pattern of the precursor is complete and has no any impurity peak.

Further detecting other physical and chemical indexes of the precursor to obtain the precursor with SSA of 6.22m²(g), TD is 2.14g/m³D50 is 4.36. mu.m.

Precursor Ni prepared in the embodiment 2 of the invention_0.65Co_0.07Mn_0.28(OH)₂And mixing the lithium ion battery with lithium and calcining to obtain the cathode material. Fig. 8 is an SEM image of the produced positive electrode material, and it can be seen from the image that the positive electrode material contains a small amount of fine powder.

Example 3

The general idea for preparing the product was the same as in example 1, except that the main components and the reaction temperature were different, and this example included the following steps:

(1) nickel, cobalt and manganese are mixed according to the metal ion molar ratio of 60: 10: 30, preparing a mixed metal salt solution with the total ion concentration of 2mol/L, wherein the precipitator is a sodium hydroxide solution, the complexing agent is ammonia water, and the gram-liter concentration of the ammonia water is 106-114 g/L.

(2) Adding deionized water into 100L of reaction kettle bottom liquid, continuously introducing nitrogen, controlling the stirring speed at 500r/min, heating to 65 ℃, introducing ammonia water and sodium hydroxide solution, and preparing the bottom liquid, wherein the initial alkalinity of the bottom liquid is controlled at 5g/L, and the pH value is controlled at 11.2;

(3) after the initial system is stable, mixed salt solution, precipitator and complexing agent are introduced into the reaction kettle with base solution in parallel flow, continuous coprecipitation reaction is carried out, the temperature of the reaction system is stabilized at 65 ℃, and A is kept_{Alkalinity of supernatant}V is 5g/l and flows into the reaction kettle in unit time_{Salt (salt)}+V_Alkali+V_AmmoniaThe total volume of the mixed solution is 100ml/min,=120, the pH value of the reaction system is 11.0-11.5, and the solid matter content in the reaction system is controlled at 130 g/l.

(4) After the granularity of the slurry of the reaction system is stable, the slurry tank collects the slurry overflowing from the overflow port of the reaction kettle, after the weight of the slurry collected in the slurry tank reaches the required sample weight, solid-liquid separation is carried out, solid materials are reserved, and after aging, circulation, washing, drying at 120 ℃ for 15 hours and screening, the molar content ratio of nickel, cobalt and manganese metal ions is 60: 10: 30 precursor Ni of high-nickel single crystal anode material_0.6Co_0.1Mn_0.3(OH)₂。

FIGS. 9 and 10 show Ni precursors prepared in example 3 of the present invention_0.6Co_0.1Mn_0.3(OH)₂SEM picture of (1), from which it can be seen that the precursor Ni_0.6Co_0.1Mn_0.3(OH)₂The primary particles are rectangular thick sheets, the primary particles are tightly packed into sphere-like secondary particles, and the dispersibility of the secondary particles is better.

FIG. 11 shows a precursor Ni prepared in example 3 of the present invention_0.6Co_0.1Mn_0.3(OH)₂The XRD pattern of the precursor is complete and has no any impurity peak.

Further examination ofMeasuring other physical and chemical indexes of the precursor to obtain the precursor with SSA of 6.78m²(g), TD is 2.08g/m³D50 is 4.19. mu.m.

Comparative example 1:

this comparative example was the same as example 1 in terms of the main component, and included the following steps:

(1) preparing a mixed metal salt solution with a total ion concentration of 2mol/L by using nickel, cobalt and manganese according to a metal ion molar ratio of 58:7:35, wherein a sodium hydroxide solution is used as a precipitator, ammonia water is used as a complexing agent, and the gram-liter concentration of the ammonia water is 106-114 g/L.

(2) Adding deionized water into 100L of reaction kettle bottom liquid, continuously introducing nitrogen, controlling the stirring speed at 500r/min, heating to 72.5 ℃, introducing ammonia water and sodium hydroxide solution, and preparing the bottom liquid, wherein the initial alkalinity of the bottom liquid is controlled at 5g/L, and the pH value is controlled at 11.2;

(3) after the initial system is stable, mixed salt solution, precipitator and complexing agent are introduced into the reaction kettle with base solution in parallel flow, continuous coprecipitation reaction is carried out, the temperature of the reaction system is stable at 72.5 ℃, and A is kept_{Alkalinity of supernatant}V is 5g/l and flows into the reaction kettle in unit time_{Salt (salt)}+V_Alkali+V_AmmoniaThe total volume of the mixed solution is 145ml/min,and =160, the pH value of the coprecipitation reaction is kept between 11.0 and 11.5, and the content of solid matters in the synthesis system is controlled to be 150 g/l.

(4) After the slurry particle size of the reaction system is stable, the slurry overflowing from the overflow port is collected by the slurry tank, solid-liquid separation is carried out after the weight of the slurry collected in the slurry tank reaches the required sample weight, the solid material is retained, and the contrast ternary precursor material Ni with relatively fine primary particles and the molar concentration ratio of nickel, cobalt and manganese metal ions of 58:7:35 is obtained after aging, circulation, washing, drying for 15 hours at 120 ℃ and screening_0.58Co_0.07Mn_0.35(OH)₂。

Fig. 12 and 13 are SEM images of the surface of the ternary precursor material having relatively fine primary particles prepared in comparative example 1 of the present invention, and fig. 14 is an XRD spectrum of the ternary precursor material having relatively fine primary particles prepared in comparative example 1 of the present invention.

As can be seen from the SEM images of fig. 12 and 13, the ternary precursor material Ni_0.58Co_0.07Mn_0.35(OH)₂The primary particles of (a) are relatively fine, and the uniformity and sphericity are slightly poor. As can be seen from the XRD spectrum of FIG. 14, the ternary precursor material Ni of comparative example 1_0.58Co_0.07Mn_0.35(OH)₂The crystal form (A) is complete and has no any impurity peak. Through detection, the precursor material Ni_0.58Co_0.07Mn_0.35(OH)₂Has an SSA of 8.02m²(g), TD is 1.94g/m³D50 is 4.48. mu.m.

Comparative example 2:

this comparative example was the same as example 2 in terms of the main components and included the following steps:

(1) nickel, cobalt and manganese are mixed according to the metal ion molar ratio of 65:7:28, preparing a mixed metal salt solution with the total ion concentration of 2mol/L, wherein the precipitator is a sodium hydroxide solution, the complexing agent is ammonia water, and the gram-liter concentration of the ammonia water is 106-114 g/L.

(2) Adding deionized water into 100L of reaction kettle bottom liquid, continuously introducing nitrogen, controlling the stirring speed at 500r/min, heating to 65 ℃, introducing ammonia water and sodium hydroxide solution, and preparing the bottom liquid, wherein the initial alkalinity of the bottom liquid is controlled at 5g/L, and the pH value is controlled at 11.2;

(3) after the initial system is stable, mixed salt solution, precipitator and complexing agent are introduced into the reaction kettle with base solution in parallel flow, continuous coprecipitation reaction is carried out, the temperature of the reaction system is stabilized at 65 ℃, and A is kept_{Alkalinity of supernatant}V is 5g/l and flows into the reaction kettle in unit time_{Salt (salt)}+V_Alkali+V_AmmoniaThe total volume of the mixed solution is 185ml/min,and =200, the pH value of the reaction system is 11.0-11.5, and the solid matter content in the reaction system is controlled at 130 g/l.

(4) Slurry of system to be reactedAfter the granularity is stable, the slurry tank collects slurry overflowing from the overflow port of the reaction kettle, after the weight of the slurry collected in the slurry tank reaches the required sample weight, solid-liquid separation is carried out, solid materials are reserved, and after aging, circulation, washing, drying at 120 ℃ for 15 hours and screening, the comparative ternary precursor material Ni with relatively fine primary particles and the molar concentration ratio of nickel, cobalt and manganese metal ions of 65:7:28 is obtained_0.65Co_0.07Mn_0.28(OH)₂。

FIGS. 15 and 16 are surface SEM images of the ternary precursor material with fine primary particles prepared in comparative example 2 of the present invention, and it can be seen from the SEM images that the ternary precursor material Ni is_0.65Co_0.07Mn_0.28(OH)₂The primary particles are fine, the uniformity and the sphericity are slightly poor, and fig. 17 is an XRD spectrogram of the primary fine-particle ternary precursor material prepared in comparative example 2 of the present invention. As can be seen from the XRD spectrum of the figure, the crystal form is complete without any impurity peak. Through detection, the precursor material Ni_0.65Co_0.07Mn_0.28(OH)₂Has an SSA of 18.05m²(g, TD 1.78 g/m)³D50 is 4.03. mu.m.

Variations and modifications to the above-described embodiments may occur to those skilled in the art, which fall within the scope and spirit of the above description. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and variations of the present invention should fall within the scope of the claims of the present invention. Furthermore, although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.