Ternary cathode material precursor and its preparation method and application

Abstract

The present application proposes a ternary positive electrode material precursor and its preparation method and application. The present application precisely controls the alkali content of the reaction system by balancing the flow rates of the metal salt solution and nitrogen to ensure that the co-precipitation process forms needle-shaped primary particles, realizes the regulation of the crystal face growth orientation, and makes the crystal face grow in a certain orientation. On different crystal faces, the flow rate of the metal salt solution is controlled so that the growth unit continuously diffuses to the crystal surface, and seeks points on the surface to combine and embed into the crystal lattice, so that the grain size ratio is within a set range. The preparation method of the present application can precisely control the size of the crystal face grain size ratio of the ternary positive electrode material precursor, and the ternary positive electrode material can inherit the crystal orientation of the precursor, so that the crystal face orientation of the ternary positive electrode material is better, and lithium ions are easier to deintercalate, thereby improving the cycle performance of the positive electrode material. The preparation method of the present application is simple, environmentally friendly, and easy to promote industrially.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a ternary positive electrode material precursor and a preparation method and application thereof. Background Art

[0002] Currently commercialized cathode materials mainly include lithium iron phosphate, lithium cobalt oxide, lithium manganese oxide, and ternary cathode materials (NCM). NCMs are typically prepared by calcining a nickel-cobalt-manganese cathode material precursor with a lithium source and / or coating it with other metal ions. The precursor can be prepared by hydroxide coprecipitation.

[0003] However, the existing ternary cathode material precursors <001> The crystal plane has a low specific surface energy. During the coprecipitation reaction, the precursor easily spreads along a specific crystal plane. However, the lithium ion transmission channel is within the active crystal plane. If the specific crystal plane size is too large, the lithium ion transmission path will become larger and the lithium ion channel will be narrow. As a result, the lithium ion deintercalation ability of the ternary positive electrode material obtained by sintering is weak, affecting the capacity of the positive electrode material. In order to improve the lithium ion transmission characteristics, it can be coated with a fast ion conductor, but this can only improve the lithium ion transmission rate on the surface of the positive electrode material. It is difficult to improve the internal transmission environment, and the use of the coating often reduces the energy density of the positive electrode material. Summary of the Invention

[0004] In view of this, the present application proposes a method for preparing a ternary cathode material precursor to regulate the crystal structure of the precursor so that the grain size ratio is within a set range, thereby improving the performance of the ternary cathode material.

[0005] In addition, it is also necessary to provide a ternary positive electrode material precursor prepared by the above preparation method, a ternary positive electrode material prepared from the ternary positive electrode material precursor, and a lithium ion battery including the ternary positive electrode material.

[0006] One embodiment of the present application provides a method for preparing a ternary cathode material precursor, comprising the following steps:

[0007] Solution preparation: nickel salt, cobalt salt and manganese salt are prepared into metal salt solution, complexing agent solution and precipitant solution are prepared;

[0008] The first stage of coprecipitation reaction is as follows: deionized water is added to the reaction vessel, and the reaction vessel is kept in a stirring state. The complexing agent solution and the precipitant solution are added to the reaction vessel to adjust the ammonia content in the reaction vessel to 2 g / L to 3 g / L and the pH value to 11 to 12; nitrogen is introduced into the reaction vessel, and the metal salt solution, the complexing agent solution, and the precipitant solution are introduced simultaneously to adjust the pH value of the reaction system to 9 to 13, so as to generate primary particles, wherein the median particle size D50 of the primary particles is 1.60 μm to 2.00 μm; wherein the flow rate of the nitrogen is n times the flow rate of the metal salt solution, and 200≤n≤1000;

[0009] The second stage of the coprecipitation reaction is as follows: the flow rate of the nitrogen gas is increased, the stirring speed of the reaction vessel is increased, and the flow rate of the metal salt solution is increased to adjust the pH of the reaction system to 9-13, so as to generate secondary particles, wherein the median particle size D50 of the secondary particles is 3.30 μm to 5.00 μm; wherein the increased flow rate of the nitrogen gas is n times the increased flow rate of the metal salt solution, and 200≤n≤1000;

[0010] Post-processing: centrifuging, washing and drying the slurry obtained from the second stage co-precipitation reaction to obtain the ternary positive electrode material precursor, wherein the grain size ratio of the ternary positive electrode material precursor satisfies the following relationship: D(100) / D(001)≤1.98.

[0011] In one embodiment, the flow rate of the nitrogen is 1.5m 3 / h~10m 3 / h, and the flow rate of the metal salt solution is 2.5L / h to 10L / h.

[0012] In one embodiment, the nickel salt is one or more of nickel sulfate, nitrate, and chloride. The cobalt salt is one or more of cobalt sulfate, nitrate, and chloride. The manganese salt is one or more of manganese sulfate, nitrate, and chloride. The concentration of the metal salt solution is 2 mol / L to 3 mol / L.

[0013] In one embodiment, the precipitant solution includes a NaOH solution or a KOH solution, and the concentration of the precipitant solution is 5 mol / L to 20 mol / L.

[0014] In one embodiment, the complexing agent solution includes one or more of ammonia water, urea, and soluble ammonium salts, and the concentration of the complexing agent solution is 2 mol / L to 10 mol / L.

[0015] In one embodiment, the reaction temperature in the reaction container is 30°C to 70°C.

[0016] One embodiment of the present application provides a ternary cathode material precursor, which is prepared by the preparation method described above. The chemical formula of the ternary cathode material precursor is Ni x Co y Mn z (OH)2, wherein 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1. The grain size ratio of the ternary positive electrode material precursor satisfies the following relationship: D(100) / D(001)≤1.98.

[0017] One embodiment of the present application provides a ternary cathode material, which is prepared from the ternary cathode material precursor as described above.

[0018] In one embodiment, the chemical formula of the ternary cathode material is LiNi x Co y Mn z (OH)2, where 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1.

[0019] One embodiment of the present application provides a lithium-ion battery, comprising the ternary cathode material as described above.

[0020] The preparation method of the present application accurately regulates the alkali content of the reaction system by balancing the flow rate (flow) of the metal salt solution and nitrogen, making the reaction system more stable and controllable, to ensure that the co-precipitation process forms needle-shaped primary particles, realizes the regulation of the crystal face growth orientation, and makes the crystal face grow in a certain orientation. On different crystal planes, the flow rate of the metal salt solution is controlled so that the growth unit continuously diffuses to the crystal surface, and seeks points on the surface to combine and embed into the crystal lattice, so that the grain size ratio is within a set range. The preparation method of the present application can accurately regulate the size of the crystal face grain size ratio of the ternary positive electrode material precursor, and the ternary positive electrode material can inherit the crystal orientation of the precursor, so that the crystal face orientation of the ternary positive electrode material is better, and lithium ions are easier to deintercalate, thereby improving the cycle performance of the positive electrode material. The preparation method of the present application is simple, environmentally friendly, and easy to promote industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning electron microscope (SEM) image of the ternary cathode material precursor of Example 1 of the present application.

[0022] Figure 2 This is an SEM image of the cross-section of the ternary cathode material precursor of Example 1 of the present application after ion milling (CP).

[0023] Figure 3 This is the SEM image of the ternary positive electrode material precursor of Comparative Example 1 of this application.

[0024] Figure 4 This is an SEM image of the cross-section of the ternary cathode material precursor of Comparative Example 1 of the present application after ion milling CP.

[0025] Figure 5 This is the X-ray diffraction (XRD) pattern of the ternary cathode material precursor of Example 1 of the present application.

[0026] Figure 6 This is the XRD pattern of the ternary cathode material precursor of Comparative Example 1 of this application.

[0027] The following specific implementation methods will further illustrate the embodiments of the present application in conjunction with the above-mentioned drawings. DETAILED DESCRIPTION

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the technical field of the present application embodiments. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present application embodiments. In the embodiments, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the reagents used or the instrument are not specified by the manufacturer, they are all conventional products that can be obtained by commercial purchase. In the case of no conflict, the features in the following embodiments and the embodiments can be combined with each other.

[0029] A first aspect of the present application provides a method for preparing a ternary cathode material precursor, comprising steps S1 to S4.

[0030] S1, solution preparation: nickel salt, cobalt salt and manganese salt are prepared into a metal salt solution, and a complexing agent solution and a precipitant solution are prepared.

[0031] S2, first stage co-precipitation reaction: deionized water is added into the reaction container to keep the reaction container in a stirring state, and the complexing agent solution and the precipitant solution are added into the reaction container to make the ammonia content in the reaction container 2g / L~3g / L and the pH value 11~12; nitrogen is introduced into the reaction container, and the metal salt solution, the complexing agent solution and the precipitant solution are introduced simultaneously to make the pH of the reaction system 9~13 to generate primary particles, and the median particle size D50 of the primary particles is 1.60pm~3.00pm; wherein, the flow rate of the nitrogen is n times the flow rate of the metal salt solution, 200≤n≤1000.

[0032] S3, second stage coprecipitation reaction: increasing the flow rate of the nitrogen gas, increasing the stirring speed of the reaction vessel, and increasing the flow rate of the metal salt solution to adjust the pH of the reaction system to 9-13, thereby generating secondary particles having a median particle size D50 of 3.30 μm to 5.00 μm; wherein the increased flow rate of the nitrogen gas is n times the increased flow rate of the metal salt solution, 200≤n≤1000;

[0033] S4, post-processing: centrifuging, washing, and drying the slurry obtained from the second stage co-precipitation reaction to obtain the ternary positive electrode material precursor, wherein the grain size ratio of the ternary positive electrode material precursor satisfies the following relationship: D(100) / D(001)≤1.98.

[0034] By balancing the flow rate (flow) of the metal salt solution and nitrogen, the alkali content of the reaction system is precisely regulated to make the reaction system more stable and controllable, to ensure that the coprecipitation process forms needle-shaped primary particles, to achieve the regulation of the crystal face growth orientation, so that the crystal face grows in a certain orientation. On different crystal planes, the flow rate of the metal salt solution is controlled so that the growth unit continuously diffuses to the crystal surface, and seeks points on the surface to combine and embed the lattice, so that the grain size ratio is within a set range. The preparation method of the present application can accurately regulate the size of the crystal face grain size ratio of the ternary positive electrode material precursor, and the ternary positive electrode material can inherit the crystal orientation of the precursor, so that the crystal face orientation of the ternary positive electrode material in the layered structure is better, the lithium deintercalation channel is increased, and the ionic conductivity is reduced, so that lithium ions are more easily deintercalated, thereby improving the cycle performance of the positive electrode material.

[0035] In some embodiments, the nickel salt is one or more of nickel sulfate, nitrate, and chloride, the cobalt salt is one or more of cobalt sulfate, nitrate, and chloride, and the manganese salt is one or more of manganese sulfate, nitrate, and chloride. For example, the nickel salt may be, but is not limited to, nickel sulfate (NiSO4·6H2O), the cobalt salt may be, but is not limited to, cobalt sulfate (CoSO4·7H2O), and the manganese salt may be, but is not limited to, manganese sulfate (MnSO4·H2O).

[0036] In some embodiments, the concentration of the metal salt solution is 2 mol / L to 3 mol / L. For example, the concentration of the metal salt solution can be 2 mol / L, 2.1 mol / L, 2.2 mol / L, 2.3 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.7 mol / L, 2.8 mol / L, 2.9 mol / L, 3 mol / L, or any value between any two adjacent values ​​thereof. The molar ratio of nickel to cobalt to manganese in the metal salt solution can be 0.95:0.03:0.02.

[0037] Furthermore, the concentration of the metal salt solution may be 2 mol / L to 2.5 mol / L.

[0038] In some embodiments, the precipitant solution includes a NaOH solution or a KOH solution, and the concentration of the precipitant solution is 5 mol / L to 20 mol / L. For example, the concentration of the precipitant solution can be 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, 11 mol / L, 15 mol / L, 16 mol / L, 18 mol / L, 20 mol / L, or any value between any two adjacent values ​​listed above.

[0039] Furthermore, the concentration of the precipitant solution may be 6 mol / L to 9 mol / L.

[0040] In some embodiments, the complexing agent solution includes one or more of ammonia (NH3·H2O), urea, and a soluble ammonium salt, and the concentration of the complexing agent solution is 2 mol / L to 10 mol / L. For example, the concentration of the complexing agent solution can be 2 mol / L, 3 mol / L, 4 mol / L, 5 mol / L, 6 mol / L, 7 mol / L, 8 mol / L, 9 mol / L, 10 mol / L, or any value between any two adjacent values ​​thereof.

[0041] Furthermore, the concentration of the complexing agent solution may be 4 mol / L to 8 mol / L.

[0042] In some embodiments, the reaction temperature in the reaction container is 30°C to 70°C.

[0043] Furthermore, the reaction temperature may be 40°C to 55°C.

[0044] In some embodiments, in steps S2 and S4, the ammonia concentration in the reaction system is 0.05 mol / L to 0.9 mol / L.

[0045] Furthermore, the ammonia concentration in the reaction system may be 0.2 mol / L to 0.5 mol / L.

[0046] In some embodiments, the reaction container may be, but is not limited to, a reactor.

[0047] The second aspect of the present application provides a ternary cathode material precursor prepared by the above preparation method, the chemical formula of which is Ni x Co y Mn z (OH)2, wherein 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1. The grain size ratio of the ternary cathode material precursor satisfies the following relationship: D(100) / D(001)≤1.98.

[0048] The third aspect of the present application provides a ternary cathode material, which can be obtained by mixing the above-mentioned ternary cathode material precursor with a lithium source and sintering. The chemical formula of the ternary cathode material is LiNi x Co y Mn z (OH)2, where 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1.

[0049] In a fourth aspect, the present application provides a lithium-ion battery comprising a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer disposed on the surface of the positive electrode current collector, wherein the positive electrode active material layer comprises the ternary positive electrode material described above.

[0050] Some implementation methods of the present application are described in detail below with reference to specific examples and comparative examples.

[0051] Example 1

[0052] S1. NiSO4·6H2O, CoSO4·7H2O, and MnSO4·H2O were weighed and dissolved in deionized water at a molar ratio of Ni:Co:Mn = 0.95:0.03:0.02 to prepare a 2.2 mol / L aqueous solution of metal salts. 7.8 mol / L of aqueous NaOH (sodium hydroxide) was used as a precipitant, and 6.5 mol / L of aqueous NH3·H2O (ammonia) was used as a complexing agent.

[0053] S2, add deionized water to the 100L reactor until it is flush with the guide cover. The temperature of the reactor is controlled at 40°C, and the stirring speed is set to 34Hz. Then, ammonia water and sodium hydroxide solution are added to adjust the bottom liquid to make the ammonia content in the reactor 2.5g / L and the pH value to 11.75. Nitrogen (99.99vol1%) is introduced into the reactor at a gas flow rate of 1.5m 3 / h. The above-configured metal salt aqueous solution, sodium hydroxide aqueous solution and ammonia water are added to the reactor simultaneously through a metering pump. The amount of the metal salt aqueous solution added is set to 2.5L / h (the flow rate of nitrogen is n times the flow rate of the metal salt solution, n=600). The amount of sodium hydroxide solution added and the amount of ammonia water added are automatically adjusted according to the pH value and ammonia concentration to ensure that the ammonia content is gradually increased to 4g / L and the pH value is gradually reduced to 11.60. The first stage coprecipitation reaction is carried out until the median particle size D50 of the obtained product is 1.60μm (micrometer). During the reaction process, the remaining clear liquid of the reaction can be discharged through a concentrator.

[0054] S3, adjust the nitrogen flow rate to 3.0m 3 / h, the pH value was gradually adjusted to 11.30, the stirring speed was increased to 36 Hz, the inlet rate of the metal salt aqueous solution was adjusted to 5 L / h (n=600), the ammonia content was maintained at 4 g / L, the pH value was gradually decreased to 11.20, and the second stage coprecipitation reaction was carried out until the median particle size D50 of the obtained product was 3.30 μm.

[0055] S4, aging the slurry obtained in step S3 (aging temperature 40°C, aging time 2h). After aging, washing it alternately with a 40°C alkaline solution and pure water, and then placing the filter cake in a hot air circulation oven at 130°C and drying it for 12h to obtain a powdered ternary positive electrode material precursor.

[0056] The SEM image of the ternary cathode material precursor prepared in Example 1 is shown in Figure 1 and Figure 2 .from Figure 1 and Figure 2 As can be seen from the figure, the precursor is a secondary particle formed by the agglomeration of primary particles, which includes a uniformly arranged dense inner core and a dense outer layer uniformly surrounding the inner core. The dense inner core has a dense structure formed by primary particles formed by stacking unit cells, and the dense outer layer has a flat structure formed by stacked lath-shaped primary particles.

[0057] Example 2

[0058] The difference between Example 2 and Example 1 is that in step S2, the flow rate of nitrogen is 2m 3 / h, n = 800; in step S3, the flow rate of nitrogen is 4m 3 / h, n = 800. The rest is the same as in Example 1 and will not be described again here.

[0059] Comparative Example 1

[0060] The difference between Comparative Example 1 and Example 1 is that in step S2, the flow rate of nitrogen is 5m 3 / h, n = 2000; in step S3, the flow rate of nitrogen is 10m 3 / h, n=2000. The rest is the same as in Example 1 and will not be described again here.

[0061] The SEM image of the ternary cathode material precursor prepared in Comparative Example 1 is shown in Figure 3 and Figure 4 .from Figure 3 and Figure 4 As can be seen from the figure, the ternary precursor material is a secondary particle formed by the agglomeration of primary particles. It includes a loose core and three dense outer layers formed on the surface of the loose core. The loose core has a honeycomb-like structure formed by the interlaced fibrous sheet-like primary particles, while the dense outer layer has a radial structure formed by lath-like primary particles.

[0062] Comparative Example 2

[0063] The difference between Comparative Example 2 and Example 1 is that in step S2, the flow rate of nitrogen is 0.2m 3 / h, n = 80; in step S3, the flow rate of nitrogen is 0.4m 3 / h, n = 80. The rest is the same as in Example 1 and will not be described again here.

[0064] The reaction parameters of the above embodiments and comparative examples are shown in Table 1.

[0065] Table 1

[0066]

[0067]

[0068] The ternary cathode material precursors of Examples 1 and 2 and Comparative Examples 1 and 2 were subjected to XRD tests respectively. The XRD patterns of Example 1 and Comparative Example 1 are shown in FIG. Figure 5 and Figure 6 According to the XRD pattern and combined with the Scherrer formula: (where K is 0.89 when β is the full width at half maximum, λ is the X-ray wavelength, and θ is the diffraction angle). The dimensions D of each crystal plane can be calculated, thereby obtaining the D(100) / D(001) grain size ratio. The XRD test equipment used was a Bruker D8 advance, with a scan range of 10–80°, a step size of 0.02, and a dwell time of 0.3 s.

[0069] According to the XRD patterns and using JADE software, the I(101) / I(001) crystal plane peak area ratios of the ternary positive electrode material precursors of Examples 1-2 and Comparative Examples 1-2 were obtained.

[0070] The median particle size D50 of the ternary cathode material precursors of Examples 1 and 2 and Comparative Examples 1 and 2 was measured using a D50 testing device: Mastersizer 3000.

[0071] The specific surface areas of the ternary cathode material precursors of Examples 1 and 2 and Comparative Examples 1 and 2 were tested using a specific surface area testing device: 3H-2000A.

[0072] The above test results are shown in Table 2.

[0073] Table 2

[0074]

[0075] The ternary cathode material precursors of Examples 1 to 2 and Comparative Examples 1 to 2 were sintered with LiOH to prepare ternary cathode materials. The ternary cathode materials of each of the above examples and comparative examples were then mixed with the conductive active material SuperP and the binder PVDF in a ratio of 90:5:5 to form a slurry, which was then evenly coated on aluminum foil to form a cathode sheet. A high-purity lithium sheet was used as the negative electrode, the diaphragm was a Celgard 2400 polypropylene diaphragm, and the electrolyte was 1 mol / L LiPF6 dissolved in a mixed solvent of EC and DMC (volume ratio of 1:1). The cells were assembled into CR2032 button cells in a vacuum glove box and then subjected to electrochemical testing. The specific test steps are as follows. The test results are shown in Table 3.

[0076] Button cells were used for electrochemical testing, with a voltage platform of 4.30 V, 2 cycles of capacity division, and 51 cycles. Data was captured using LANDdtV7 software to obtain charge and discharge capacity, initial efficiency (constant capacity discharge capacity in grams / total charge capacity in grams), and DCR data.

[0077] Table 3

[0078]

[0079] As can be seen from Table 3, the batteries prepared in Examples 1 to 2 of the present application have a total charge capacity in grams, a constant-capacity discharge capacity in grams, a first-efficiency capacity, and a second-cycle discharge capacity in grams that are higher than those of the batteries in Comparative Examples 1 to 2, and a charge DCR and a discharge DCR that are lower than those of the batteries in Comparative Examples 1 to 2, indicating that the precursors prepared in Examples 1 to 2 of the present application can improve the electrochemical performance of the battery, so that the battery has a higher capacity and better cycle performance.

[0080] The preparation method of the present application accurately regulates the alkali content of the reaction system by balancing the flow rate (flow) of the metal salt solution and nitrogen, making the reaction system more stable and controllable, to ensure that the co-precipitation process forms needle-shaped primary particles, realizes the regulation of the crystal face growth orientation, and makes the crystal face grow in a certain orientation. On different crystal planes, the flow rate of the metal salt solution is controlled so that the growth unit continuously diffuses to the crystal surface, and seeks points on the surface to combine and embed into the crystal lattice, so that the grain size ratio is within a set range. The preparation method of the present application can accurately regulate the size of the crystal face grain size ratio of the ternary positive electrode material precursor, and the ternary positive electrode material can inherit the crystal orientation of the precursor, so that the crystal face orientation of the ternary positive electrode material is better, and lithium ions are easier to deintercalate, thereby improving the cycle performance of the positive electrode material. The preparation method of the present application is simple, environmentally friendly, and easy to promote industrialization.

[0081] The above description is some specific implementation methods of the present application, but in actual application, it is not limited to these implementation methods. For ordinary technicians in this field, other variations and changes made according to the technical concept of the present application should fall within the scope of protection of the present application.

Claims

1. A method for preparing a ternary cathode material precursor, characterized in that: The preparation method comprises the following steps: Solution preparation: nickel salt, cobalt salt and manganese salt are prepared into metal salt solution, complexing agent solution and precipitant solution are prepared; The first stage of the coprecipitation reaction comprises: adding deionized water to a reaction vessel, maintaining the reaction vessel in a stirring state, adding the complexing agent solution and the precipitant solution to the reaction vessel, adjusting the ammonia content in the reaction vessel to 2 g / L to 3 g / L and the pH value to 11 to 12; introducing nitrogen gas into the reaction vessel, and simultaneously introducing the metal salt solution, the complexing agent solution, and the precipitant solution to adjust the pH value of the reaction system to 9 to 13, to generate primary particles, wherein the median particle size D50 of the primary particles is 1.60 μm to 2.00 μm; wherein the flow rate of the nitrogen gas is n times the flow rate of the metal salt solution, and 600≤n≤800; The second stage of the coprecipitation reaction is as follows: the flow rate of the nitrogen gas is increased, the stirring speed of the reaction vessel is increased, and the flow rate of the metal salt solution is increased to adjust the pH of the reaction system to 9-13, so as to generate secondary particles, wherein the median particle size D50 of the secondary particles is 3.30 μm-5.00 μm; wherein the increased flow rate of the nitrogen gas is n times the increased flow rate of the metal salt solution, and 600≤n≤800; Post-processing: centrifuging, washing, and drying the slurry obtained from the second-stage coprecipitation reaction to obtain the ternary cathode material precursor, wherein the grain size ratio of the ternary cathode material precursor satisfies the following relationship: D(100) / D(001)≤1.83; The flow rate of the nitrogen is 1.5m 3 / h~10m 3 / h, and the flow rate of the metal salt solution is 2.5L / h~10L / h.

2. The preparation method according to claim 1, wherein The nickel salt is one or more of nickel sulfate, nitrate, and chloride; the cobalt salt is one or more of cobalt sulfate, nitrate, and chloride; the manganese salt is one or more of manganese sulfate, nitrate, and chloride; and the concentration of the metal salt solution is 2 mol / L to 3 mol / L.

3. The preparation method according to claim 1, wherein The precipitant solution includes a NaOH solution or a KOH solution, and the concentration of the precipitant solution is 5 mol / L to 20 mol / L.

4. The preparation method according to claim 1, wherein The complexing agent solution includes one or more of ammonia water, urea, and soluble ammonium salts, and the concentration of the complexing agent solution is 2 mol / L to 10 mol / L.

5. The preparation method according to claim 1, wherein The reaction temperature in the reaction container is 30°C to 70°C.

6. A ternary cathode material precursor, characterized in that: The ternary cathode material precursor is prepared by the preparation method according to any one of claims 1 to 5, and the chemical formula of the ternary cathode material precursor is Ni x Co y Mn z (OH)2, wherein 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1; the grain size ratio of the ternary positive electrode material precursor satisfies the following relationship: D(100) / D(001)≤1.

83.

7. A ternary cathode material, characterized in that: The ternary positive electrode material is prepared from the ternary positive electrode material precursor as claimed in claim 6.

8. The ternary cathode material according to claim 7, wherein: The chemical formula of the ternary cathode material is LiNi x Co y Mn z (OH)2, where, 0.6≤x<1, 0<y<0.2, 0<z<0.2, x+y+z=1.

9. A lithium-ion battery, characterized in that: Comprising the ternary positive electrode material as described in claim 7 or 8.

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