阅读说明：本技术 一种高电压镍钴锰三元前驱体及其制备方法 (High-voltage nickel-cobalt-manganese ternary precursor and preparation method thereof ) 是由 黄亚祥 郑江峰 张颖 兰超波 于 2021-07-30 设计创作，主要内容包括：本发明涉及镍钴锰三元前驱体制造领域,具体涉及高电压镍钴锰三元前驱体及其制备方法。制备方法：将镍钴锰三元金属盐溶液、碳酸盐溶液、络合剂溶液与第一底液混合进行共沉淀反应,待沉淀达到所需粒径范围后固液分离,得到镍钴锰复合碱式碳酸盐晶种；将镍钴锰三元金属盐溶液、沉淀剂溶液、氨水溶液与含有镍钴锰复合碱式碳酸盐晶种的第二底液混合,使镍钴锰复合碱式碳酸盐晶种继续生长,待晶种达到所需粒径范围后进行固液分离,干燥,混批,过筛,除磁,得到内核为镍钴锰复合碱式碳酸盐、外壳为镍钴锰复合氢氧化物的三元前驱体。该前驱体制备的三元正极材料组装的电池在4.5V高截止电压下表现出高放电容量、高首次库伦效率和优异的倍率性能。(The invention relates to the field of manufacturing of nickel-cobalt-manganese ternary precursors, in particular to a high-voltage nickel-cobalt-manganese ternary precursor and a preparation method thereof. The preparation method comprises the following steps: mixing a nickel-cobalt-manganese ternary metal salt solution, a carbonate solution, a complexing agent solution and a first base solution for coprecipitation reaction, and performing solid-liquid separation after the precipitate reaches a required particle size range to obtain a nickel-cobalt-manganese composite basic carbonate seed crystal; and mixing the nickel-cobalt-manganese ternary metal salt solution, the precipitant solution, the ammonia water solution and the second base solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal to enable the nickel-cobalt-manganese composite basic carbonate seed crystal to continue to grow, carrying out solid-liquid separation after the seed crystal reaches a required particle size range, drying, mixing, screening and demagnetizing to obtain the ternary precursor with the core being the nickel-cobalt-manganese composite basic carbonate and the shell being the nickel-cobalt-manganese composite hydroxide. A battery assembled by the ternary cathode material prepared by the precursor shows high discharge capacity, high first coulombic efficiency and excellent rate capability under the high cut-off voltage of 4.5V.)

1. A preparation method of a high-voltage nickel-cobalt-manganese ternary precursor is characterized by comprising the following steps:

(a) mixing a nickel-cobalt-manganese ternary metal salt solution, a carbonate solution, a complexing agent solution and a first base solution in an inert atmosphere, carrying out coprecipitation reaction, and after the precipitate reaches a required particle size range, carrying out solid-liquid separation to obtain a nickel-cobalt-manganese composite basic carbonate seed crystal;

(b) mixing a nickel-cobalt-manganese ternary metal salt solution, a precipitator solution, an ammonia water solution and a second base solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal under an inert atmosphere, continuously growing the nickel-cobalt-manganese composite basic carbonate seed crystal, and after the seed crystal reaches a required particle size range, carrying out solid-liquid separation, drying, mixing, screening and demagnetizing to obtain a high-voltage nickel-cobalt-manganese ternary precursor with a nickel-cobalt-manganese composite basic carbonate as an inner core and a nickel-cobalt-manganese composite hydroxide as an outer shell;

wherein, in step (a), the carbonate salt comprises at least one of sodium carbonate, potassium carbonate, and sodium bicarbonate;

in step (a), the complexing agent comprises at least one of ethylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, and hexamethylenetetramine.

2. The method according to claim 1, wherein in step (a), the precipitate is formed to have a desired particle size in the range of D50 ═ 2 to 5 μm;

preferably, in the step (b), the seed crystal has a desired particle size range of D50 ═ 5 to 10 μm, more preferably D50 ═ 5.5 to 9 μm.

3. The method according to claim 1, wherein in step (a), the carbonate solution has a molar concentration of 0.5 to 2.5mol/L, more preferably 1 to 2 mol/L;

preferably, in the step (a), the molar concentration of the metal ions in the nickel-cobalt-manganese ternary metal salt solution is 0.5-2.5 mol/L, and more preferably 1-2 mol/L;

preferably, in the step (a), the molar ratio of the nickel element, the cobalt element and the manganese element in the nickel-cobalt-manganese ternary metal salt solution is 40-95: 2-30: 2-30;

preferably, in the step (a), the feeding speed of the complexing agent solution is 0.02-0.2 times of the feeding speed of the nickel-cobalt-manganese ternary metal salt solution;

preferably, in the step (a), the mass concentration of the complexing agent solution is 1.0-4.0 g/L;

preferably, in the step (a), the pH of the first base solution is 7.5-8.5.

4. The preparation method according to claim 1, wherein in the step (a), the temperature of the solution system is 35 to 60 ℃, more preferably 36 to 50 ℃ during the coprecipitation reaction;

preferably, in the step (a), in the process of performing the coprecipitation reaction, the pH of the solution system is 7 to 9, and more preferably 7.2 to 8.5;

preferably, in the step (a), after the solid-liquid separation, a step of washing the separated precipitate is further included.

5. The method according to claim 1, wherein in the step (b), the second base solution has a pH of 10 to 12, more preferably 10.5 to 11.0; the mass concentration of free ammonia in the second base solution is 2-9 g/L, and more preferably 3-8 g/L;

preferably, in the step (b), in the process of continuously growing the nickel-cobalt-manganese composite basic carbonate seed crystal, the mass concentration of free ammonia in the solution system is 3-8 g/L, and more preferably 4-7 g/L;

preferably, in the step (b), in the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, the temperature of the solution system is 45-70 ℃, and more preferably 50-65 ℃;

preferably, in the step (b), in the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, the pH of a solution system is 10-12, and more preferably 10.5-11;

preferably, in the step (b), stirring is performed during the process of continuously growing the nickel-cobalt-manganese composite basic carbonate seed crystal, and the rotation speed of the stirring is 100-400 rpm, and more preferably 200-300 rpm.

6. The preparation method according to claim 1, wherein in the step (b), the molar concentration of metal ions in the nickel-cobalt-manganese ternary metal salt solution is 1-2 mol/L;

preferably, in the step (b), the molar ratio of the nickel element, the cobalt element and the manganese element in the nickel-cobalt-manganese ternary metal salt solution is 40-98: 2-30: 2-30;

preferably, in step (b), the precipitating agent comprises sodium hydroxide;

preferably, in step (b), the mass fraction of the precipitant solution is 18% to 35%, more preferably 20% to 32%;

preferably, in the step (b), the mass fraction of the ammonia water solution is 10% to 18%, more preferably 12% to 15%.

7. The method according to claim 1, wherein the drying temperature in step (b) is 105 to 150 ℃, more preferably 120 to 130 ℃.

8. A high-voltage nickel-cobalt-manganese ternary precursor prepared by the preparation method of any one of claims 1 to 7.

9. A lithium ion battery anode material is prepared by adopting a high-voltage nickel-cobalt-manganese ternary precursor prepared by the preparation method of any one of claims 1 to 7 or the high-voltage nickel-cobalt-manganese ternary precursor of claim 8 and a lithium salt;

preferably, the molar ratio of the high-voltage nickel-cobalt-manganese ternary precursor to the lithium salt is 1: 1.05-1.12.

10. A lithium ion battery comprising a positive electrode prepared from the positive electrode material of claim 9.

Technical Field

The invention relates to the technical field of nickel-cobalt-manganese ternary precursor manufacturing, in particular to a high-voltage nickel-cobalt-manganese ternary precursor and a preparation method thereof, and more particularly relates to a high-voltage lithium ion battery nickel-cobalt-manganese ternary positive electrode material precursor modified through special structural design and a preparation method thereof, a lithium ion battery positive electrode material and a lithium ion battery.

Background

The field of 3C lithium batteries (i.e., capacity type lithium ion batteries made of material systems such as lithium nickel cobalt manganese oxide and lithium manganese oxide represented by mobile phones, tablet computers, notebook computers, and the like) is the main application market of lithium cobalt oxide, along with the acceleration of 5G commercialization, the high cobalt price and the continuous emergence of novel electronic products, the light weight, the thin weight and the long standby requirements of smart phones, tablet computers and novel consumer electronic products are met, the energy density requirement on battery materials is further improved, and the market application of the lithium nickel cobalt manganese oxide positive electrode material with the characteristics of high voltage and high compaction is further increased. The long-term endurance requirement and the volume limitation of the lithium battery promote the low-cost high-voltage nickel cobalt lithium manganate battery to become the future development trend in the field of consumer electronics.

The nickel cobalt manganese hydroxide (also called ternary precursor) is a key raw material for preparing the nickel cobalt lithium manganate, the particle size, the impurity content, the morphology, the crystal structure and the like of the nickel cobalt manganese hydroxide have good inheritance, and the performance directly determines the electrochemical performance of the nickel cobalt lithium manganate anode material.

However, the nickel-cobalt-manganese ternary positive electrode material precursor in the prior art is a secondary spherical particle formed by agglomeration of primary particles of fine grains, and has a compact structure and a low specific surface area. The nickel-cobalt-manganese ternary cathode material has some problems to be solved urgently, such as rapid cycle capacity attenuation under a high-voltage condition, low first coulombic efficiency, agglomerated particle pulverization, poor rate capability, poor structure stability and the like, and the application of the nickel-cobalt-manganese ternary cathode material under the high-voltage condition can be limited.

In addition, with the increase of the cycle number of the lithium battery under high voltage, the lithium ion battery prepared from the ternary precursor may have the defects of crushing, pulverization and structural collapse caused by expansion and contraction of secondary particles, increase of battery impedance and reduction of active ingredients, aggravate side reaction with electrolyte, serious capacity attenuation, and rapid reduction of multiplying power and cycle performance, so that the battery bulges, expands and even fires.

Therefore, the special precursor for the high-voltage nickel cobalt lithium manganate positive electrode material is of great significance.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The first purpose of the invention is to provide a preparation method of a high-voltage nickel-cobalt-manganese ternary precursor, which comprises the steps of firstly preparing a ternary positive electrode material precursor seed crystal (namely, a nickel-cobalt-manganese composite basic carbonate with a chemical formula of [ Ni ]_aCo_bMn_c]₃(OH)₄CO₃(ii) a Wherein a + b + c is 1, a: b: c is 40-95: 2-30: 2-30), and growing to obtain a ternary precursor-basic nickel cobalt manganese carbonate composite salt with a special structure, namely a high-voltage nickel cobalt manganese ternary precursor with a nickel cobalt manganese composite basic carbonate as an inner core and a nickel cobalt manganese composite hydroxide as an outer shell. During the lithium preparation and sintering process of the ternary cathode material prepared from the precursor, when the basic carbonate with loose and porous inner core is converted into oxide, certain structural oxygen defects and oxygen cavities can be formed, and then the cathode material with microporous inner core and compact shell can be formed. Therefore, when the anode material is subjected to work circulation under the condition of high voltage, the capacitance of the anode material is better kept, and the high-voltage performance of the ternary anode material is improved; meanwhile, the single crystal ternary material obtained by the method has higher first-cycle coulombic efficiency due to low cation mixed-discharging degree and larger single particle diameter.

In addition, the preparation method has the advantages of simple operation, low requirement on production equipment, large-scale production, high efficiency and the like.

The second purpose of the invention is to provide the high-voltage nickel-cobalt-manganese ternary precursor, which has the advantages of large specific surface area, loose surface and thick primary particle strip, is a primary particle shape and secondary particle aggregate with a special structure, and has no obvious agglomeration phenomenon; the special structure enables the sintering process to have more advantages compared with the conventional sintering process, can increase lithium ion diffusion channels, and can remarkably improve the cycle performance and rate capability of the lithium ion battery under the high-voltage working condition when the high-voltage nickel-cobalt-manganese ternary precursor is applied to the anode material; meanwhile, the high-voltage nickel-cobalt-manganese ternary precursor has excellent high-voltage performance.

The third purpose of the invention is to provide a lithium ion battery anode material, which can remarkably improve the cycle performance and the rate capability of the lithium ion battery under the high-voltage working condition by adopting a high-voltage nickel-cobalt-manganese ternary precursor with a special structure.

The fourth purpose of the invention is to provide a lithium ion battery which has excellent cycle performance and rate capability under high-voltage working conditions.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

a preparation method of a high-voltage nickel-cobalt-manganese ternary precursor comprises the following steps:

(a) mixing a nickel-cobalt-manganese ternary metal salt solution, a carbonate solution, a complexing agent solution and a first base solution in an inert atmosphere, carrying out coprecipitation reaction, and after the precipitate reaches a required particle size range, carrying out solid-liquid separation to obtain a nickel-cobalt-manganese composite basic carbonate seed crystal;

(b) mixing a nickel-cobalt-manganese ternary metal salt solution, a precipitator solution, an ammonia water solution and a second base solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal under an inert atmosphere, continuously growing the nickel-cobalt-manganese composite basic carbonate seed crystal, and after the seed crystal reaches a required particle size range, carrying out solid-liquid separation, drying, mixing, screening and demagnetizing to obtain a high-voltage nickel-cobalt-manganese ternary precursor with a nickel-cobalt-manganese composite basic carbonate as an inner core and a nickel-cobalt-manganese composite hydroxide as an outer shell;

wherein, in step (a), the carbonate salt comprises at least one of sodium carbonate, potassium carbonate, and sodium bicarbonate;

in step (a), the complexing agent comprises at least one of ethylenediaminetetraacetic acid, ethylenediaminetetrapropionic acid, and hexamethylenetetramine.

The chemical formula of the nickel-cobalt-manganese composite basic carbonate is [ Ni ]_aCo_bMn_c]₃(OH)₄CO₃(ii) a Wherein a + b + c is 1, a: b: c is 40-95: 2-30: 2 to 30.

The preparation method of the high-voltage nickel-cobalt-manganese ternary precursor provided by the invention comprises the steps of firstly preparing a ternary positive electrode material precursor seed crystal (namely, nickel-cobalt-manganese composite basic carbonate), and then growing to obtain a ternary precursor-basic nickel-cobalt-manganese carbonate composite salt with a special structure, namely, the high-voltage nickel-cobalt-manganese ternary precursor with a nickel-cobalt-manganese composite basic carbonate as an inner core and a nickel-cobalt-manganese composite hydroxide as an outer shell. During the lithium preparation and sintering process of the ternary cathode material prepared from the precursor, when the basic carbonate with loose and porous inner core is converted into oxide, certain structural oxygen defects and oxygen cavities can be formed, and then the cathode material with microporous inner core and compact shell can be formed. Therefore, when the anode material is subjected to work circulation under the condition of high voltage, the capacitance of the anode material is better kept, and the high-voltage performance of the ternary anode material is improved; meanwhile, the single crystal ternary material obtained by the method has higher first-cycle coulombic efficiency due to low cation mixed-discharging degree and larger single particle diameter.

In addition, the preparation method has the advantages of simple operation, low requirement on production equipment, large-scale production, high efficiency and the like.

Preferably, in the step (a), the coprecipitation reaction is performed in a reaction kettle a, the reaction kettle a is matched with a thickener, the slurry in the reaction kettle a is subjected to solid extraction, and the material after the mother liquor is removed can be returned to the reaction kettle a for continuous reaction, so that the reaction kettle a can be continuously fed.

Preferably, the carbonate consists of sodium carbonate; or the carbonate consists of sodium carbonate and potassium carbonate; alternatively, the carbonate salt consists of sodium carbonate and sodium bicarbonate; alternatively, the carbonate salt consists of sodium carbonate, potassium carbonate and sodium bicarbonate.

Preferably, in the step (B), the process of continuously growing the nickel-cobalt-manganese composite basic carbonate seed crystal is performed in a reaction kettle B, the reaction kettle B is provided with a thickener, the slurry in the reaction kettle is lifted and solidified, the material from which the mother solution is removed can be returned to the reaction kettle B for continuous reaction, so that the reaction kettle B can be continuously fed.

And taking the nickel-cobalt-manganese composite basic carbonate seed crystal as a nucleus to perform continuous growth in the reaction kettle B, wherein the secondary growth of the ternary precursor is to pile secondary particles on seed crystal particles, so that the crystal structure of the precursor can be accurately regulated and controlled, and finally the high-voltage precursor product is obtained.

Ethylenediaminetetraacetic acid (EDTA) is an organic compound that is a white powder at ambient temperature and pressure and can act as a chelating agent.

Ethylenediaminetetraacetic acid (EDTP), also known as ethylenediaminetetraacetic acid, 3 ', 3 ", 3' - (ethylenedinitrilo) tetrapropionic acid.

Hexamethylenetetramine, also known as urotropin, cyclohexamethylene tetramine.

Preferably, in step (a), the precipitate reaches a desired particle size range of D50 ═ 2 to 5 μm, and may also be selected to be 2.5 μm, 3 μm, 3.5 μm, 4 μm or 4.5 μm.

Preferably, in step (b), the seed crystal has a desired particle size range of D50 ═ 5 to 10 μm, more preferably D50 ═ 5.5 to 9 μm, and may further be selected from 6 μm, 6.5 μm, 7 μm, 7.5 μm, 8 μm, or 8.5 μm.

According to the high-voltage nickel-cobalt-manganese ternary precursor provided by the invention, the inner core cannot be too large, the diameter of the whole precursor sphere is D, the diameter of the inner core is D, and the ratio of the diameter of the inner core to the diameter of the whole sphere is preferably kept to be 0.2-0.5; thus, the effects of loose inner core and compact shell can be achieved. When D/D is too large, the tap density of the finally prepared nickel-cobalt-manganese ternary precursor is small, the specific surface area is too large, and finally the capacity of the positive electrode material is low and the cycle is poor; long cycling under high voltage conditions can lead to structural collapse. When D/D is too small, the structure of the inner core loose micropores can not be fully utilized, the improvement effect on the precursor structure is poor, and the performance improvement is smaller compared with the conventional product sold in the market.

Preferably, in the step (a), the carbonate solution has a molar concentration of 0.5-2.5 mol/L, and more preferably 1-2 mol/L; 1.2mol/L, 1.4mol/L, 1.6mol/L or 1.8mol/L can also be selected.

Preferably, in the step (a), the molar concentration of the metal ions in the nickel-cobalt-manganese ternary metal salt solution is 0.5-2.5 mol/L, and more preferably 1-2 mol/L; 1.2mol/L, 1.4mol/L, 1.6mol/L or 1.8mol/L can also be selected.

Preferably, in the step (a), the molar ratio of the nickel element, the cobalt element and the manganese element in the nickel-cobalt-manganese ternary metal salt solution is 40-95: 2-30: 2 to 30.

Preferably, in the step (a), the feeding speed of the complexing agent solution is 0.02-0.2 times of the feeding speed of the nickel-cobalt-manganese ternary metal salt solution. Wherein the feed rate is given in units of: l/h.

Preferably, in the step (a), the mass concentration of the complexing agent solution is 1.0-4.0 g/L.

Preferably, in the step (a), the pH of the first base solution is 7.5-8.5; alternatively, 7.7, 7.9, 8.0, 8.1, 8.3 or 8.4 may be used.

Preferably, in step (a), the first base solution is an aqueous solution of sodium hydroxide.

Preferably, in the step (a), during the coprecipitation reaction, the temperature of the solution system is 35 to 60 ℃, and more preferably 36 to 50 ℃; it is also possible to select 38 deg.C, 39 deg.C, 41 deg.C, 42 deg.C, 43 deg.C, 45 deg.C, 47 deg.C, 48 deg.C or 49 deg.C.

Preferably, in the step (a), in the process of performing the coprecipitation reaction, the pH of the solution system is 7 to 9, and more preferably 7.2 to 8.5; alternatively, 7.3, 7.4, 7.6, 7.8, 8.0, 8.2, 8.3 or 8.4 may be used.

Preferably, in the step (a), after the solid-liquid separation, a step of washing the separated precipitate is further included.

Preferably, the means for solid-liquid separation comprises filtration.

Preferably, nitrogen is also introduced for protection during the filtration and washing process, so as to avoid seed oxidation.

Mother liquor can be removed through filtration, trace sodium ions, sulfate ions and carbonate ions in the system can be removed through washing, and therefore pure nickel-cobalt-manganese composite basic carbonate seed crystal precipitate is obtained.

Preferably, in the step (b), the pH of the second base solution is 10-12, and more preferably 10.5-11.0; alternatively 10.7, 10.8 or 10.9.

Preferably, in the step (b), the mass concentration of the free ammonia in the second base solution is 2-9 g/L, and more preferably 3-8 g/L; 4g/L, 4.5g/L, 5g/L, 5.5g/L, 6g/L, 6.5g/L, 7g/L, or 7.5g/L may also be selected.

Preferably, in the step (b), in the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, the mass concentration of free ammonia in the solution system is 3-8 g/L, more preferably 4-7 g/L, and also can be selected to be 5g/L, 5.5g/L, 6g/L, 6.5g/L or 6.8 g/L.

The free ammonia refers to the concentration of total ammonium ions in the solution system.

Preferably, in the step (b), in the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, the temperature of the solution system is 45-70 ℃, and more preferably 50-65 ℃; it can also be selected from 52 deg.C, 53 deg.C, 54 deg.C, 55 deg.C, 57 deg.C, 59 deg.C, 61 deg.C, 62 deg.C, 63 deg.C or 64 deg.C.

Preferably, in the step (b), in the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, the pH of the solution system is 10-12, and more preferably 10.5-11.

Preferably, in the step (b), stirring is performed during the process of continuing to grow the nickel-cobalt-manganese composite basic carbonate seed crystal, wherein the stirring speed is 100-400 rpm, more preferably 200-300 rpm, and may also be 210rpm, 220rpm, 230rpm, 240rpm, 250rpm, 260rpm, 270rpm, 280rpm or 290 rpm.

Preferably, in the step (b), the molar concentration of the metal ions in the nickel-cobalt-manganese ternary metal salt solution is 1-2 mol/L.

Preferably, in the step (b), the molar ratio of the nickel element, the cobalt element and the manganese element in the nickel-cobalt-manganese ternary metal salt solution is 40-98: 2-30: 2 to 30.

Preferably, in step (b), the precipitating agent comprises sodium hydroxide.

Preferably, in step (b), the precipitant solution is 18 to 35% by mass, more preferably 20 to 32% by mass, and may also be selected from 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30% or 31% by mass.

Preferably, in the step (b), the mass fraction of the ammonia water solution is 10% to 18%, more preferably 12% to 15%, and also 12.5%, 13% or 14% can be selected.

Preferably, in the step (b), the drying temperature is 105-150 ℃, and 110 ℃, 115 ℃, 120 ℃, 125 ℃, 130 ℃, 135 ℃, 140 ℃ or 145 ℃ can be selected; more preferably 120 to 130 ℃.

The invention provides a high-voltage nickel-cobalt-manganese ternary precursor which is prepared by the preparation method.

The invention also provides a lithium ion battery anode material which is prepared by adopting the high-voltage nickel-cobalt-manganese ternary precursor prepared by the preparation method or the high-voltage nickel-cobalt-manganese ternary precursor and a lithium salt.

Preferably, the molar ratio of the high-voltage nickel-cobalt-manganese ternary precursor to the lithium salt is 1: 1.05-1.12.

The high-voltage nickel-cobalt-manganese ternary precursor provided by the invention has the advantages of large specific surface area, loose surface and thick primary particle strip, is a primary particle shape and secondary particle aggregate with a special structure, and has no obvious agglomeration phenomenon; the special structure enables the sintering process to have more advantages compared with the conventional sintering process, can increase lithium ion diffusion channels, and can remarkably improve the cycle performance and rate capability of the lithium ion battery under the high-voltage working condition when the high-voltage nickel-cobalt-manganese ternary precursor is applied to the anode material; meanwhile, the high-voltage nickel-cobalt-manganese ternary precursor has excellent high-voltage performance.

More preferably, the preparation method of the lithium ion battery cathode material specifically comprises the following steps:

(1) mixing with lithium: uniformly mixing the prepared high-voltage nickel-cobalt-manganese ternary precursor and lithium source powder according to a metered molar ratio of 1:1.05-1:1.12, adding zirconium oxide and yttrium oxide, and uniformly mixing by using a high-speed mixer to obtain mixed powder;

(2) and (3) calcining: demagnetizing, filling the mixed powder, cutting into blocks, stacking, conveying the mixed powder into a roller kiln for sintering and cooling, unloading, roughly crushing, sieving and demagnetizing to obtain the nickel-cobalt-manganese ternary cathode material, and obtaining Zr and Y element co-doped LiNi_aCo_bMn_cO₂A substrate, wherein a + b + c is 1, a: b: c is 40-95: 2-30: 2-30, wherein the doping amount of Zr is 1500ppm of the mass of the substrate, and the doping amount of Y is 1100ppm of the mass of the substrate.

The lithium ion battery anode material provided by the invention can obviously improve the cycle performance and rate capability of the lithium ion battery under the high-voltage working condition by adopting the high-voltage nickel-cobalt-manganese ternary precursor with a special structure.

Preferably, the lithium ion battery positive electrode comprises a positive electrode prepared from the lithium ion battery positive electrode material.

The lithium ion battery provided by the invention has excellent cycle performance and rate capability under a high-voltage working condition.

More preferably, the lithium ion battery comprises the lithium ion battery anode material prepared by the method as described above; assembling the lithium ion battery anode material into a button cell by the following method: mixing a positive electrode material, conductive carbon and polyvinylidene fluoride (PVDF) according to a mass ratio of 92.5: 5: 2.5 adding into N-methyl-2 pyrrolidone (NMP), mixing to obtain positive slurry, coating on the positive current collector, vacuum drying to obtain positive electrode, and assembling into 2025 button cell in glove box by using lithium sheet as negative electrode.

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

(1) the preparation method of the high-voltage nickel-cobalt-manganese ternary precursor provided by the invention comprises the steps of firstly preparing a ternary anode material precursor seed crystal (namely, nickel-cobalt-manganese composite basic carbonate with a chemical formula of [ Ni ]_aCo_bMn_c]₃(OH)₄CO₃(ii) a Wherein a + b + c is 1, a: b: c is 40-95: 2-30: 2-30), and growing to obtain a ternary precursor-basic nickel cobalt manganese carbonate composite salt with a special structure, namely a high-voltage nickel cobalt manganese ternary precursor with a nickel cobalt manganese composite basic carbonate as an inner core and a nickel cobalt manganese composite hydroxide as an outer shell. During the lithium preparation and sintering process of the ternary cathode material prepared from the precursor, when the basic carbonate with loose and porous inner core is converted into oxide, certain structural oxygen defects and oxygen cavities can be formed, and then the cathode material with microporous inner core and compact shell can be formed. Therefore, when the anode material is subjected to work circulation under the condition of high voltage, the capacitance of the anode material is better kept, and the high-voltage performance of the ternary anode material is improved; meanwhile, the single crystal ternary material obtained by the method has higher first-cycle coulombic efficiency due to low cation mixed-discharging degree and larger single particle diameter. In addition, the preparation method is simple to operate, has low requirements on production equipment, can realize large-scale production and has high efficiency.

(2) The high-voltage nickel-cobalt-manganese ternary precursor provided by the invention has the advantages of large specific surface area, loose surface and thick primary particle strip, is in a primary particle shape and secondary particle aggregate with a special structure, and has no obvious agglomeration phenomenon; the special structure enables the sintering process to have more advantages compared with the conventional sintering process, can increase lithium ion diffusion channels, and can remarkably improve the cycle performance and rate capability of the lithium ion battery under the high-voltage working condition when the high-voltage nickel-cobalt-manganese ternary precursor is applied to the anode material; meanwhile, the high-voltage nickel-cobalt-manganese ternary precursor has excellent high-voltage performance.

(3) The lithium ion battery anode material provided by the invention can obviously improve the cycle performance and rate capability of the lithium ion battery under the high-voltage working condition by adopting the high-voltage nickel-cobalt-manganese ternary precursor with a special structure.

(4) The lithium ion battery provided by the invention has excellent cycle performance and rate capability under a high-voltage working condition.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 shows Ni provided in example 1 of the present invention_0.60Co_0.200Mn_0.20(OH)₂Scanning electron microscope images of the precursor;

FIG. 2 shows Ni provided in example 1 of the present invention_0.60Co_0.200Mn_0.20(OH)₂The particle size distribution diagram of the precursor;

FIG. 3 is a LiNi according to example 6 of the present invention_0.60Co_0.20Mn_0.60O₂XRD pattern of matrix;

FIG. 4 shows LiNi according to example 6 of the present invention_0.60Co_0.20Mn_0.60O₂The matrix is assembled into a first charge-discharge curve chart of the 2025 button cell.

Detailed Description

The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and the detailed description, but those skilled in the art will understand that the following described embodiments are some, not all, of the embodiments of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

Example 1

The high voltage nickel-cobalt-manganese ternary precursor Ni provided by the embodiment_0.60Co_0.20Mn_0.20(OH)₂The preparation method comprises the following steps:

(a) simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 1.2mol/L, the molar ratio of nickel elements to cobalt elements to manganese elements is 6:2:2), a sodium carbonate aqueous solution (the molar concentration is 1.5mol/L) and EDTA (ethylene diamine tetraacetic acid) into a reaction kettle A containing a first base solution (a sodium hydroxide solution with the pH value of 7.5) and rich in nitrogen at a constant speed through a metering pump, and carrying out coprecipitation reaction; in the reaction process, the temperature of the solution system is controlled at 40 ℃, the pH value is controlled at 7.5, and the feeding speed of the complexing agent solution (with the mass concentration of 1.0g/L) is 0.02 times of that of the nickel-cobalt-manganese ternary metal salt solution; and stopping feeding when the material in the reaction kettle A reaches the specified granularity D50 ═ 2.5 micrometers, and filtering and washing the material in the reaction kettle A to obtain the nickel-cobalt-manganese composite basic carbonate seed crystal.

(b) Transferring the nickel-cobalt-manganese composite basic carbonate seed crystal into a reaction kettle B, adding pure water to a half kettle liquid level covering the reaction kettle B, adding a sodium hydroxide solution and ammonia water to enable the pH of a solution system to be 10.50 and the mass concentration of free ammonia to be 5.5g/L, and obtaining a second bottom solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal; then, simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration is 2.0mol/L, the molar ratio of nickel to cobalt to manganese is 6:2:2), a sodium hydroxide solution (the mass fraction is 30%) and ammonia water (the mass fraction is 15%) into a reaction kettle B which is rich in nitrogen at a constant speed through a metering pump, and enabling the seed crystals to continue to grow; in the process of carrying out coprecipitation reaction by continuing to grow the seed crystal, the system temperature of the solution is controlled at 60 ℃, the pH value is controlled at 10.8, the concentration of free ammonia in the solution is 5.5g/L, and the stirring speed is 260 rpm; stopping feeding when the material in the reaction kettle B reaches the target particle size D50 which is 6.0 mu m;

and then conveying the precursor slurry reaching the target granularity in the reaction kettle B to a centrifuge for filtering and washing, then placing the slurry in a drying oven at 105 ℃ for drying, and obtaining the high-voltage nickel-cobalt-manganese ternary precursor with the core being nickel-cobalt-manganese composite basic carbonate and the shell being nickel-cobalt-manganese composite hydroxide after mixing, screening, demagnetizing and packaging.

Tests prove that the high-voltage nickel-cobalt-manganese ternary precursor prepared by the embodiment has the center particle size of 6.0 mu m and the specific surface area of 15.2m²(ii)/g, tap density 1.54g/cm³。

Example 2

The high voltage nickel-cobalt-manganese ternary precursor Ni provided by the embodiment_0.60Co_0.20Mn_0.20(OH)₂The preparation method comprises the following steps:

(a) simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 1.5mol/L, the molar ratio of nickel elements to cobalt elements to manganese elements is 6:2:2), a sodium carbonate aqueous solution (the molar concentration is 1.5mol/L) and ethylene diamine tetrapropionic acid (EDTP) into a reaction kettle A containing a first base solution (a sodium hydroxide solution with the pH value of 8.5) and rich in nitrogen at a constant speed through a metering pump, and carrying out coprecipitation reaction; in the reaction process, the temperature of the solution system is controlled at 35 ℃, the pH value is controlled at 8, and the feeding speed of the complexing agent solution (with the mass concentration of 2.0g/L) is 0.15 times of that of the nickel-cobalt-manganese ternary metal salt solution; and stopping feeding when the material in the reaction kettle A reaches the specified granularity D50 ═ 4.0 mu m, and filtering and washing the material in the reaction kettle A to obtain the nickel-cobalt-manganese composite basic carbonate seed crystal.

(b) Transferring the nickel-cobalt-manganese composite basic carbonate seed crystal into a reaction kettle B, adding pure water to a half kettle liquid level covering the reaction kettle B, adding a sodium hydroxide solution and ammonia water to enable the pH of a solution system to be 10 and the mass concentration of free ammonia to be 3g/L, and obtaining a second bottom solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal; then, simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration is 2.0mol/L, the molar ratio of nickel to cobalt to manganese is 6:2:2), a sodium hydroxide solution (the mass fraction is 32%) and ammonia water (the mass fraction is 14%) into a reaction kettle B which is rich in nitrogen at a constant speed through a metering pump, and enabling the seed crystals to continue to grow; in the process of carrying out coprecipitation reaction by continuing to grow the seed crystal, the system temperature of the solution is controlled at 50 ℃, the pH value is controlled at 10.5, the concentration of free ammonia in the solution is 3g/L, and the stirring speed is 200 rpm; stopping feeding when the material in the reaction kettle B reaches the target particle size D50 ═ 8 mu m;

and then conveying the precursor slurry reaching the target granularity in the reaction kettle B to a centrifuge for filtering and washing, then placing the slurry in a drying oven at 120 ℃ for drying, and obtaining the high-voltage nickel-cobalt-manganese ternary precursor with the core being nickel-cobalt-manganese composite basic carbonate and the shell being nickel-cobalt-manganese composite hydroxide after mixing, screening, demagnetizing and packaging.

Tests prove that the high-voltage nickel-cobalt-manganese ternary precursor prepared by the embodiment has the center particle size of 6.0 mu m and the specific surface area of 16.6m²(ii)/g, tap density 1.51g/cm³。

Example 3

The high voltage nickel-cobalt-manganese ternary precursor Ni provided by the embodiment_0.60Co_0.20Mn_0.20(OH)₂The preparation method comprises the following steps:

(a) simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 1.8mol/L, the molar ratio of nickel elements to cobalt elements to manganese elements is 6:2:2), a sodium carbonate aqueous solution (the molar concentration is 1.0mol/L) and EDTA (ethylene diamine tetraacetic acid) into a reaction kettle A containing a first base solution (a sodium hydroxide solution with the pH value of 8.0) and rich in nitrogen at a constant speed through a metering pump, and carrying out coprecipitation reaction; in the reaction process, the temperature of a solution system is controlled at 40 ℃, the pH value is controlled at 7.2, and the feeding speed of a complexing agent solution (with the mass concentration of 3.0g/L) is 0.08 times of that of a nickel-cobalt-manganese ternary metal salt solution; and stopping feeding when the material in the reaction kettle A reaches the specified granularity D50 ═ 2.5 micrometers, and filtering and washing the material in the reaction kettle A to obtain the nickel-cobalt-manganese composite basic carbonate seed crystal.

(b) Transferring the nickel-cobalt-manganese composite basic carbonate seed crystal into a reaction kettle B, adding pure water to a half kettle liquid level covering the reaction kettle B, adding a sodium hydroxide solution and ammonia water to enable the pH of a solution system to be 11 and the mass concentration of free ammonia to be 7.5g/L, and obtaining a second bottom solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal; then, simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration is 1.0mol/L, the molar ratio of nickel to cobalt to manganese is 6:2:2), a sodium hydroxide solution (the mass fraction is 20%) and ammonia water (the mass fraction is 12%) into a reaction kettle B which is rich in nitrogen at a constant speed through a metering pump, and enabling the seed crystals to continue to grow; in the process of carrying out coprecipitation reaction by continuing to grow the seed crystal, the system temperature of the solution is controlled at 65 ℃, the pH value is controlled at 11, the concentration of free ammonia in the solution is 7g/L, and the stirring speed is 300 rpm; stopping feeding when the material in the reaction kettle B reaches the target particle size D50 ═ 8.0 μm;

and then conveying the precursor slurry reaching the target granularity in the reaction kettle B to a centrifuge for filtering and washing, then placing the slurry in an oven at 130 ℃ for drying, and obtaining the high-voltage nickel-cobalt-manganese ternary precursor with the core being nickel-cobalt-manganese composite basic carbonate and the shell being nickel-cobalt-manganese composite hydroxide after mixing, screening, demagnetizing and packaging.

Tests prove that the high-voltage nickel-cobalt-manganese ternary precursor prepared by the embodiment has the center particle size of 8.0 mu m and the specific surface area of 13.6m²(ii)/g, tap density 1.64g/cm³。

Example 4

The high voltage nickel-cobalt-manganese ternary precursor Ni provided by the embodiment_0.80Co_0.10Mn_0.10(OH)₂The preparation method comprises the following steps:

(a) simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 1mol/L, the molar ratio of nickel elements to cobalt elements to manganese elements is 8:1:1), an aqueous solution of sodium carbonate (the molar concentration is 2.0mol/L) and hexamethylenetetramine into a reaction kettle A containing a first base solution (a sodium hydroxide solution with the pH value of 7.8) and rich in nitrogen at a constant speed through a metering pump, and carrying out coprecipitation reaction; in the reaction process, the temperature of the solution system is controlled at 50 ℃, the pH value is controlled at 8.2, and the feeding speed of the complexing agent solution (with the mass concentration of 4.0g/L) is 0.05 times of that of the nickel-cobalt-manganese ternary metal salt solution; and stopping feeding when the material in the reaction kettle A reaches the specified granularity D50 ═ 5.0 mu m, and filtering and washing the material in the reaction kettle A to obtain the nickel-cobalt-manganese composite basic carbonate seed crystal.

(b) Transferring the nickel-cobalt-manganese composite basic carbonate seed crystal into a reaction kettle B, adding pure water to a half kettle liquid level covering the reaction kettle B, adding a sodium hydroxide solution and ammonia water to enable the pH of a solution system to be 10 and the mass concentration of free ammonia to be 4g/L, and obtaining a second bottom solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal; then, simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration is 1.0mol/L, the molar ratio of nickel to cobalt to manganese is 8:1:1), a sodium hydroxide solution (the mass fraction is 19%) and ammonia water (the mass fraction is 11%) into a reaction kettle B rich in nitrogen respectively at a constant speed through a metering pump, and enabling the seed crystals to continue to grow; in the process of carrying out coprecipitation reaction by continuing to grow the seed crystal, the system temperature of the solution is controlled at 47 ℃, the pH value is controlled at 10.5, the concentration of free ammonia in the solution is 4.5g/L, and the stirring speed is 180 rpm; stopping feeding when the material in the reaction kettle B reaches the target granularity D50 ═ 9.0 μm;

and then conveying the precursor slurry reaching the target granularity in the reaction kettle B to a centrifuge for filtering and washing, then placing the slurry in an oven at 150 ℃ for drying, and obtaining the high-voltage nickel-cobalt-manganese ternary precursor with the core being nickel-cobalt-manganese composite basic carbonate and the shell being nickel-cobalt-manganese composite hydroxide after mixing, screening, demagnetizing and packaging.

Tests prove that the high-voltage nickel-cobalt-manganese ternary precursor prepared by the embodiment has the center particle size of 9.0 mu m and the specific surface area of 14.8m²(ii)/g, tap density 15.1g/cm³。

Example 5

The high voltage nickel-cobalt-manganese ternary precursor Ni provided by the embodiment_0.95Co_0.05Mn_0.05(OH)₂The preparation method comprises the following steps:

(a) simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 2mol/L, the molar ratio of nickel elements to cobalt elements is 95:5:5), a sodium carbonate aqueous solution (the molar concentration is 1.8mol/L) and EDTA (ethylene diamine tetraacetic acid) into a reaction kettle A containing a first base solution (a sodium hydroxide solution with the pH value of 8.0) and rich in nitrogen at a constant speed through a metering pump, and carrying out coprecipitation reaction; in the reaction process, the temperature of the solution system is controlled at 55 ℃, the pH value is controlled at 8.5, and the feeding speed of the complexing agent solution (with the mass concentration of 2.5g/L) is 0.18 times of that of the nickel-cobalt-manganese ternary metal salt solution; and stopping feeding when the material in the reaction kettle A reaches the specified granularity D50 ═ 4.0 mu m, and filtering and washing the material in the reaction kettle A to obtain the nickel-cobalt-manganese composite basic carbonate seed crystal.

(b) Transferring the nickel-cobalt-manganese composite basic carbonate seed crystal into a reaction kettle B, adding pure water to a half kettle liquid level covering the reaction kettle B, adding a sodium hydroxide solution and ammonia water to enable the pH of a solution system to be 11.7 and the mass concentration of free ammonia to be 8.5g/L, and obtaining a second bottom solution containing the nickel-cobalt-manganese composite basic carbonate seed crystal; then, simultaneously feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration is 1.5mol/L, the molar ratio of nickel to cobalt to manganese is 95:5:5), a sodium hydroxide solution (the mass fraction is 34%) and ammonia water (the mass fraction is 17%) into a reaction kettle B which is rich in nitrogen at a constant speed through a metering pump, and enabling the seed crystals to continue to grow; in the process of carrying out coprecipitation reaction by continuing to grow the seed crystal, the system temperature of the solution is controlled at 67 ℃, the pH value is controlled at 11.5, the concentration of free ammonia in the solution is 8g/L, and the stirring speed is 150 rpm; stopping feeding when the material in the reaction kettle B reaches the target granularity D50 ═ 9.5 μm;

and then conveying the precursor slurry reaching the target granularity in the reaction kettle B to a centrifuge for filtering and washing, then placing the slurry in an oven at 125 ℃ for drying, and obtaining the high-voltage nickel-cobalt-manganese ternary precursor with the core being nickel-cobalt-manganese composite basic carbonate and the shell being nickel-cobalt-manganese composite hydroxide after mixing, screening, demagnetizing and packaging.

Tests prove that the high-voltage nickel-cobalt-manganese ternary precursor prepared by the embodiment has the center particle size of 9.5 mu m and the specific surface area of 10.5m²(ii)/g, tap density 1.71g/cm³。

Example 6

The preparation method of the lithium ion battery provided by the embodiment comprises the following steps:

(1) mixing with lithium: adding zirconium oxide and yttrium oxide into the high-voltage nickel-cobalt-manganese ternary precursor prepared in the embodiment 1 and lithium source powder according to a metered molar ratio of 1:1.05, and uniformly mixing the zirconium oxide and the yttrium oxide by using a high-speed mixer to obtain mixed powder;

(2) and (3) calcining: demagnetizing, filling the mixed powder, cutting into blocks, stacking, conveying the mixed powder into a roller kiln for sintering and cooling, unloading, roughly crushing, sieving and demagnetizing to obtain the nickel-cobalt-manganese ternary cathode material, and obtaining Zr and Y element co-doped LiNi_0.60Co_0.20Mn_0.20O₂The doping amount of Zr is 1500ppm of the mass of the substrate, and the doping amount of Y is 1100ppm of the mass of the substrate.

(3) Assembling the lithium ion battery anode material prepared in the step (2) into a button cell according to the following method: mixing a positive electrode material, conductive carbon and polyvinylidene fluoride (PVDF) according to a mass ratio of 92.5: 5: 2.5 adding into N-methyl-2 pyrrolidone (NMP), mixing to obtain positive slurry, coating on the positive current collector, vacuum drying to obtain positive electrode, and assembling into 2025 button cell in glove box by using lithium sheet as negative electrode.

Example 7

The preparation method of the lithium ion battery provided in this example is substantially the same as that of example 6, except that, in step (1), the high-voltage nickel-cobalt-manganese ternary precursor is prepared from example 2, and the molar ratio of the high-voltage nickel-cobalt-manganese ternary precursor to the lithium source powder is replaced by 1: 1.12.

Example 8

The preparation method of the lithium ion battery provided in this embodiment is substantially the same as that of embodiment 6, except that, in step (1), the high-voltage nickel-cobalt-manganese ternary precursor is prepared from embodiment 3, and the molar ratio of the high-voltage nickel-cobalt-manganese ternary precursor to the lithium source powder is replaced by 1: 1.1.

Example 9

The preparation method of the lithium ion battery provided in this embodiment is substantially the same as that of embodiment 6, except that, in step (1), the high-voltage nickel-cobalt-manganese ternary precursor is prepared from embodiment 4.

Example 10

The preparation method of the lithium ion battery provided in this embodiment is substantially the same as that of embodiment 6, except that, in step (1), the high-voltage nickel-cobalt-manganese ternary precursor is prepared from embodiment 5.

Comparative example 1

The preparation method of the nickel-cobalt-manganese hydroxide precursor provided by the comparative example comprises the following steps:

(1) feeding a mixed solution of nickel sulfate, cobalt sulfate and manganese sulfate (the total molar concentration of nickel-cobalt-manganese metal ions is 2.0mol/L, the molar ratio of nickel elements to cobalt elements to manganese elements is 6:2:2), 30 wt% of NaOH solution and 15 wt% of ammonia water into a reaction kettle B at a constant speed through a metering pump, respectively, controlling the temperature of a reaction system at 60 ℃, the pH value at 10.7-10.8, the concentration of free ammonia in the solution at 5.5g/L, the stirring speed at 260rpm, and stopping feeding when the material in the reaction kettle B reaches the target particle size D50 of 6.0 microns.

(2) And conveying the qualified precursor slurry in the reaction kettle B to a centrifuge for filtering, washing, drying in an oven, mixing, sieving, demagnetizing and packaging to obtain the nickel-cobalt-manganese hydroxide precursor.

The preparation method of the lithium ion battery provided by the comparative example is basically the same as that of example 6, except that the high-voltage nickel-cobalt-manganese ternary precursor in the step (1) is replaced by the nickel-cobalt-manganese hydroxide precursor prepared by the comparative example.

Test example 1

The high-voltage nickel-cobalt-manganese ternary precursor Ni prepared in the embodiment 1 of the invention_0.60Co_0.20Mn_0.20(OH)₂Scanning electron microscope detection and particle size detection are carried out, and the test results are respectively shown in figures 1-2.

LiNi prepared in example 6 of the present invention_0.60Co_0.20Mn_0.60O₂XRD detection is carried out on the matrix, and the test result is shown in figure 3.

As can be seen from fig. 1, the high-voltage nickel-cobalt-manganese ternary precursor prepared in embodiment 1 of the present invention is a spherical particle with uniform morphology and compact structure. The primary fiber of the precursor particles is in a strip shape, the basic size of the primary fiber is a strip body with the length of 1-3 mu m and the width of 200-400 nm, and the whole precursor particles are in a loose and porous sphere-like shape; and the obtained precursor is uniformly and intensively distributed, has a smooth surface, good sphericity and no obvious agglomeration phenomenon.

As can be seen from FIG. 2, Ni prepared in example 1 of the present invention_0.60Co_0.20Mn_0.20(OH)₂The precursor has narrow particle size distribution and no small balls.

As can be seen from fig. 3, the (003)/(104) peak intensity ratio is 1.78, which indicates that the nickel-lithium mixed condition in the ternary material is weak and basically disappears completely; and the peak divisions of (006)/(102) and (108)/(110) are obvious, which shows that the material has a complete layered material structure and high crystallinity. Therefore, the nickel cobalt lithium manganate ternary cathode material provided by the invention has the advantages of excellent crystal form, perfect crystal lattice and basically no defect.

LiNi prepared in example 6 of the present invention_0.60Co_0.20Mn_0.60O₂The substrate is assembled into a 2025 button cell in a glove box, and a first charge and discharge test is performed under a high voltage system, and as shown in fig. 4, a first charge and discharge curve diagram of the cell is shown.

As can be seen from FIG. 4, the first charge capacity of 0.2C is 227.7mAh/g, the first specific discharge capacity is 202.6mAh/g, and the first efficiency of the button cell is 88.99% within the voltage range of 2.8-4.5V after the button cell is used, which is superior to the products prepared by the conventional reaction in the market.

Test example 2

Electrochemical performance tests were performed on the lithium ion batteries prepared in the above examples and comparative examples of the present invention using a CT2001A type battery detection system, which is a blue-ray electronics ltd, wuhan, and the test results are shown in table 1 below.

TABLE 1 electrochemical test results (2.8-4.5V) of lithium ion batteries of examples and comparative examples

As can be seen from Table 1, the invention is adopted under high voltage system (2.8-4.5V): the cathode material prepared from the ternary precursor obtained in the embodiment 1 is optimal in performance in lithium ions, the first discharge capacity of the cathode material is as high as 202.6mAh/g, the first discharge capacity is 12.6mAh/g higher than that of the precursor prepared by the conventional method (comparative example 1), and the first efficiency is 88.99%; the capacity retention rate of the lithium ion battery is 4-6% higher than that of the lithium ion battery discharged under high rate, and the capacity retention rate is improved by 5-10 mAh/g; is suitable for precursors with different nickel-cobalt-manganese ratios.

While particular embodiments of the present invention have been illustrated and described, it will be appreciated that the above embodiments are merely illustrative of the technical solution of the present invention and are not restrictive; those of ordinary skill in the art will understand that: modifications may be made to the above-described embodiments, or equivalents may be substituted for some or all of the features thereof without departing from the spirit and scope of the present invention; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; it is therefore intended to cover in the appended claims all such alternatives and modifications that are within the scope of the invention.