Nanometer flaky ternary precursor as well as preparation method and application thereof

Abstract

The invention discloses a nanosheet-shaped ternary precursor as well as a preparation method and application thereof, and belongs to the technical field of new energy. The preparation method of the nanosheet-shaped ternary precursor provided by the invention comprises the following steps: mixing a mixed solution containing a surfactant and a metal salt, an ammonia water solution and an alkali solution for reaction; the surface active agent is a carboxylic acid ammonium salt surface active agent. According to the preparation method provided by the invention, the prepared nanosheet-shaped ternary precursor has good dispersity, and then the prepared monocrystal ternary positive electrode material has good dispersity and electrochemical performance. The invention also provides the nanosheet-shaped ternary precursor prepared by the preparation method and application of the nanosheet-shaped ternary precursor.

Description

Technical Field

[0001] The present invention relates to the field of new energy technology, and in particular to a nano-sheet-shaped ternary precursor and a preparation method and application thereof. Background Art

[0002] Single-crystal ternary cathodes are primary particles without grain boundaries, boasting high crystalline purity and strong mechanical strength. Compared to traditional polycrystalline ternary cathode materials, they offer improved surface chemical stability and high-temperature storage performance, improving mechanical stability during cycling and helping to suppress capacity fade. Dispersion is a key technical indicator for single-crystal ternary cathodes. Highly dispersed single crystal materials can significantly improve tapped and compacted density, while reducing microcracks caused by anisotropy during cycling.

[0003] The ternary precursors required for single crystal preparation are typically small, spherical particles. The dispersion of the precursors has a direct impact on the dispersion of the single crystals. During the coprecipitation reaction, due to their small size and large specific surface area, small particles are difficult to disperse quickly and are prone to agglomeration.

[0004] Therefore, there is an urgent need to find a preparation method that can significantly improve the dispersibility of small-particle ternary single crystal precursors and thus optimize the electrochemical performance of ternary positive electrode materials. Summary of the Invention

[0005] The present invention aims to address at least one of the technical problems existing in the prior art. To this end, the present invention provides a method for preparing a nanosheet-like ternary precursor, which effectively improves the dispersibility of the resulting nanosheet-like ternary precursor and, in turn, enhances the electrochemical performance of a single-crystal ternary cathode material obtained from the nanosheet-like ternary precursor.

[0006] The present invention also provides a nano-sheet-shaped ternary precursor prepared by the above preparation method.

[0007] The present invention also provides applications of the nanosheet-shaped ternary precursor.

[0008] According to an embodiment of the first aspect of the present invention, a method for preparing a nanosheet-shaped ternary precursor is provided, the method comprising reacting a mixed solution containing a surfactant and a metal salt, an ammonia solution, and an alkaline solution;

[0009] The surfactant is an ammonium carboxylate surfactant;

[0010] In the mixed solution, the concentration of the surfactant is 1 to 10 g / L.

[0011] The preparation method according to the embodiment of the present invention has at least the following beneficial effects:

[0012] The precursor prepared by the above preparation method has good dispersibility, is in the form of flakes and nanometer-scale. After sintering, the single crystal ternary single crystal positive electrode is easier to crush and the dispersibility is significantly improved.

[0013] Compared with other types of surfactants, the carboxylic acid ammonium salt surfactant used in the present invention contains abundant carboxyl groups and amino groups, is easily adsorbed on the surface of the whiskers, helps to inhibit the whiskers from agglomerating into balls, and simultaneously has the function of guiding the direction of crystal growth. Therefore, it can not only improve the dispersibility and particle size uniformity of the obtained precursor, but also form a specific nano-sheet structure.

[0014] Furthermore, the present invention further limits the particle size of the obtained product by limiting the concentration of the surfactant, thereby avoiding adverse factors such as agglomeration caused by too small particle size and the impact of too large particle size on the subsequent positive electrode material performance.

[0015] According to some embodiments of the present invention, the surfactant includes at least one of ammonium isostearate (CAS: 191880-49-6), ammonium laurate (CAS: 2437-23-2), ammonium stearate (CAS: 1002-89-7), tetraammonium ethylenediaminetetraacetate (CAS: 22473-78-5), triethanolammonium oleate (CAS: 2717-15-9), triethanolammonium cocoyl glutamate, N-cocoyl glutamate, perfluorocarboxylate ammonium salt, hydrogenated ammonium rosinate, and ammonium rosinate. The ratio of carboxyl groups to amino groups in the surfactant is 1:1. The ratio of carboxyl groups to amino groups affects the morphology and diameter of the dispersed nanosheets. At the same molar concentration, the greater the number of carboxyl groups / amino groups in the surfactant, the stronger its effect on the morphology of the precursor and the easier it is to form dispersed nanosheets.

[0016] According to some embodiments of the present invention, the concentration of the surfactant in the mixed solution is 2 to 9 g / L, for example, about 2 g / L, 3 g / L, 4 g / L, 5 g / L, 6 g / L, 7 g / L, 8 g / L, or about 9 g / L.

[0017] According to some embodiments of the present invention, the metal salt is at least one of sulfate, chloride and nitrate.

[0018] According to some embodiments of the present invention, the metal salt is a nickel salt, a cobalt salt, and a manganese salt.

[0019] According to some embodiments of the present invention, the mixed solution further includes a doping source. The present invention does not impose strict restrictions on the type and concentration of the doping source, and the doping source can be selected and the concentration adjusted as needed in actual production.

[0020] According to some embodiments of the present invention, the concentration of the metal salt in the mixed solution is 1.5 to 2.0 mol / L, for example, about 1.5 mol / L, 1.8 mol / L, or about 2.0 mol / L.

[0021] According to some embodiments of the present invention, the ammonia concentration in the ammonia solution is 4 to 6 mol / L, for example, about 4.5 mol / L, 5 mol / L, or about 5.5 mol / L.

[0022] According to some embodiments of the present invention, the concentration of the alkali in the alkaline solution is 8 to 12 mol / L, for example, about 9 mol / L, 10 mol / L, or about 11 mol / L.

[0023] According to some embodiments of the present invention, the temperature of the mixing reaction is 40°C to 70°C, for example, about 45°C, 50°C, 55°C, 60°C or about 65°C.

[0024] According to some embodiments of the present invention, the pH of the mixed reaction is between 9 and 12, for example, about 10 or about 11.

[0025] According to some embodiments of the present invention, the mixing reaction is carried out under stirring.

[0026] According to some embodiments of the present invention, the stirring speed in the stirring state is 300-600 rpm, for example, about 400 rpm or about 500 rpm.

[0027] According to some embodiments of the present invention, the mixing reaction lasts for 30 to 50 hours, for example, about 35 hours, 40 hours, or about 45 hours.

[0028] According to some embodiments of the present invention, the preparation method comprises the following steps:

[0029] S1. The mixed solution, ammonia solution and alkaline solution are mixed and flowed into the pure water bottom liquid for reaction;

[0030] S2. The product obtained in step S1 is subjected to solid-liquid separation, washing and drying.

[0031] According to some embodiments of the present invention, in step S1, the flow rate ratio of the mixed solution to the ammonia solution is 10 to 20:1; wherein,

[0032] The flow rate ratio of the mixed solution to the ammonia solution is 15 to 18:1; for example, it can be about 16:1 or about 17:1.

[0033] The flow rate of the alkaline solution can be adjusted according to the actual pH required.

[0034] According to an embodiment of the second aspect of the present invention, a nanosheet-shaped ternary precursor prepared by the preparation method provided in the embodiment of the first aspect of the present invention is provided, wherein the chemical expression of the nanosheet-shaped ternary precursor is: Ni x Co y Mn z (OH)2, wherein 0.5≤x≤1, 0≤y≤0.5, 0≤z≤0.5, x+y+z=1.

[0035] Since the nanosheet-shaped ternary precursor adopts all the technical solutions of the preparation method of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0036] The nanosheet-like ternary precursor provided by the present invention can effectively inhibit the mixing of cations in the crystal lattice, improve the structural stability of the single-crystal ternary positive electrode material prepared therefrom, facilitate faster and more stable insertion and extraction of lithium ions, and enhance the specific capacity, rate and cycle performance of the single-crystal ternary positive electrode material.

[0037] According to some embodiments of the present invention, the nanosheet-shaped ternary precursor, Ni x Co y Mn z (OH)2, 0.8≤x≤1, 0.01≤y≤0.1, 0.01≤z≤0.1. More specifically:

[0038] 0.9≤x≤0.95; for example, it may be about 0.92, 0.93 or about 0.94;

[0039] 0.02≤y≤0.08; for example, it may be about 0.04, 0.05, 0.06 or about 0.07;

[0040] 0.01≤z≤0.05; for example, it may be approximately 0.02, 0.03 or approximately 0.04.

[0041] According to some embodiments of the present invention, the nanosheet-shaped ternary precursor has a circular, nearly circular, or elliptical shape.

[0042] According to some embodiments of the present invention, the equivalent diameter of the nanosheet-shaped ternary precursor is 200-1000 nm, for example, about 200 nm, 300 nm, 500 nm, 600 nm, 700 nm, 800 nm, or about 900 nm.

[0043] According to some embodiments of the present invention, the BET of the nanosheet-shaped ternary precursor is 10 to 30 m 2 / g. For example, it can be about 15m 2 / g, 20m 2 / g、21m 2 / g, 21.5m 2 / g、22m 2 / g, 25m 2 / g or about 30m 2 / g.

[0044] According to some embodiments of the present invention, the TD of the nanosheet-shaped ternary precursor is 0.3 to 1.5 g / cm 3 For example, it can be about 0.5g / cm 3 , 0.6g / cm 3 , 0.7g / cm 3 , 0.8g / cm 3 , 1.0g / cm 3 or about 1.2g / cm 3 .

[0045] According to some embodiments of the present invention, the grain size D001 of the nanosheet-shaped ternary precursor is 12-20 nm, for example, about 14 nm, 15 nm, 16 nm, 16.5 nm, 17 nm, 17.5 nm, or about 18 nm.

[0046] According to some embodiments of the present invention, the peak intensity ratio I001 / I101 of the nanosheet-shaped ternary precursor is 0.8 to 2.0, for example, about 0.9, 0.98, 1.0, 1.2, 1.4, or about 1.5.

[0047] According to an embodiment of the third aspect of the present invention, a single crystal ternary cathode material is provided. The single crystal ternary cathode material is obtained by mixing and sintering the nanosheet-shaped ternary precursor provided by the second aspect of the present invention and a lithium source.

[0048] Since the single crystal ternary cathode material adopts all the technical solutions of the nano-sheet ternary precursor of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0049] The present invention does not impose strict restrictions on the ratio of the nanosheet-like ternary precursor and the lithium source, as well as the atmosphere and temperature of the mixed sintering. In actual production, the particle size of the nanosheet-like ternary precursor and the metal ratio therein can be conventionally adjusted.

[0050] According to an embodiment of the fourth aspect of the present invention, a lithium-ion battery is provided, wherein the raw materials for preparing the lithium-ion battery include the single crystal ternary positive electrode material provided by the embodiment of the third aspect of the present invention.

[0051] Since the lithium-ion battery adopts all the technical solutions of the single crystal ternary cathode material of the above embodiment, it has at least all the beneficial effects brought by the technical solutions of the above embodiment.

[0052] In the lithium-ion battery, the single crystal ternary positive electrode material serves as the positive electrode active material; the corresponding negative electrode active material, conductive agent and other auxiliary materials, and battery types are not strictly limited by the present invention. In actual production, routine adjustments can be made based on the available test conditions and actual performance requirements.

[0053] Unless otherwise specified, the term “about” in the present invention actually means that the error is allowed to be within the range of ±2%, for example, about 100 actually means 100±2%×100.

[0054] Unless otherwise specified, “between” in the present invention includes the number itself, for example, “between 2 and 3” includes the endpoint values 2 and 3.

[0055] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of the embodiments with reference to the accompanying drawings, in which:

[0057] Figure 1 This is an SEM image of the nanosheet-like ternary precursor obtained in Example 1 of the present invention.

[0058] Figure 2 This is an SEM image of the nanosheet-like ternary precursor obtained in Example 2 of the present invention.

[0059] Figure 3 This is an SEM image of the ternary precursor obtained in Comparative Example 1 of the present invention.

[0060] Figure 4 This is an SEM image of the ternary precursor obtained in Comparative Example 2 of the present invention.

[0061] Figure 5 This is an SEM image of the ternary precursor obtained in Comparative Example 3 of the present invention.

[0062] Figure 6 This is an SEM image of the ternary precursor obtained in Comparative Example 4 of the present invention. DETAILED DESCRIPTION

[0063] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0064] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0065] Example 1

[0066] This embodiment prepares a nano-sheet ternary precursor. Specifically, the preparation method is as follows:

[0067] S1. A metal salt solution containing Ni, Co, and Mn sulfate having a total metal ion concentration of 2 mol / L was prepared, wherein the molar ratio of Ni, Co, and Mn was 94:4:2; a surfactant tetraammonium ethylenediaminetetraacetate was added to the metal salt liquid to obtain a mixed solution, wherein the concentration of the surfactant was 2 g / L;

[0068] Prepare 10 mol / L sodium hydroxide solution;

[0069] Prepare 5 mol / L ammonia solution.

[0070] The above mixed solution was added to the pure water base liquid at a flow rate of 5 L / h and the ammonia solution was added at a flow rate of 0.3 L / h. During the reaction, the temperature was controlled at 50°C, the flow rate of sodium hydroxide was adjusted to control the pH to 11, and the rotation speed was 500 rpm. The reaction time was about 40 h.

[0071] S2. The obtained solid-liquid mixture is filtered, separated, washed and dried to obtain a nanosheet-shaped ternary precursor, the chemical formula of which is Ni 0.94 Co 0.04 Mn 0.02 (OH)2.

[0072] Example 2

[0073] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0074] In step S1, the surfactant is ammonium isostearate (CAS: 191880-49-6) with a concentration of 8 g / L.

[0075] Example 3

[0076] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0077] In step S1, the concentration of the surfactant is 1 g / L.

[0078] Example 4

[0079] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0080] In step S1, the concentration of the surfactant is 10 g / L.

[0081] Example 5

[0082] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0083] In step S1, the concentration of the surfactant is 5 g / L.

[0084] Comparative Example 1

[0085] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0086] In step S1, no surfactant is added to the mixed solution.

[0087] Comparative Example 2

[0088] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0089] In step S1, the concentration of the surfactant is 15 g / L.

[0090] Comparative Example 3

[0091] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0092] The surfactant in step S1 was replaced with polyvinylpyrrolidone of equal concentration.

[0093] Comparative Example 4

[0094] This example prepares a ternary precursor. Specifically, the preparation method differs from that of Example 1 in that:

[0095] The surfactant in step S1 was replaced with polyvinyl alcohol of equal concentration.

[0096] Application Example 1

[0097] In this example, a single crystal ternary cathode material was prepared. The specific steps are as follows:

[0098] The nanosheet-shaped ternary precursors obtained in the Examples and Comparative Examples were uniformly mixed with lithium hydroxide, with a molar ratio of the sum of nickel, cobalt, and manganese (metal ions) to lithium of 1:1.03. The mixture was then sintered in two stages under an oxygen atmosphere. The first stage was sintered at 700°C, held for 4 hours, and ramped at 4°C / min. The second stage was sintered at 950°C, held for 10 hours, and ramped at 8°C / min. After cooling to room temperature, the sintered product was ground and passed through a 400-mesh sieve.

[0099] Application Example 2

[0100] This example prepares a lithium-ion battery, specifically:

[0101] The single crystal ternary positive electrode material obtained in Application Example 1: the conductive agent: the binder are mixed in a mass ratio of 80:10:10 to form a positive electrode slurry, which is then coated on the surface of aluminum foil, dried, and cut to form a positive electrode sheet; lithium metal is used as the negative electrode sheet; and a conventional PE material separator is used to assemble it into a button battery.

[0102] Test Example 1

[0103] This example tests the physical and chemical properties of the ternary precursors obtained in the examples and comparative examples, wherein the morphology is tested by SEM, the specific surface area is tested by BET, the TD is tested by a tap density meter, and the peak intensity ratio and grain size are tested by XRD. The results show that the products obtained in Examples 1 to 5 are dispersed nanosheets with a nanosheet diameter of ~700±200nm; combining the results of Example 1 and Examples 3-5, it can be seen that the more surfactant is used, the larger the BET and TD, the lower the peak intensity ratio, and the smaller the grain size; compared with Example 1, Example 2 has a similar number of carboxyl / amino groups, and the BET and TD are close, but the XRD peak intensity of Example 2 is relatively low, and the grain size is slightly smaller; in Comparative Example 1, no surfactant is added, and the obtained ternary precursor is spherical particles; in Comparative Example 2, the surfactant concentration is 15g / L, and the morphology of the obtained ternary precursor is nanosheet, but the size of the nanosheet is obviously small, with a diameter of no more than 100nm, and agglomeration occurs between the nanosheets, and the BET is large; Comparative Example 3 is a polyvinyl pyrrolidone surfactant, and the obtained ternary precursor is spherical particles, but the sphericity is poor and the TD is high; Comparative Example 4 is a polyvinyl alcohol surfactant, and the primary particles of the obtained ternary precursor are thick hexagonal sheets, but the hexagonal sheets are severely agglomerated, the BET is low, and the grain size is large. The specific results are shown in Table 1 and Figures 1 to 6 shown

[0104] Table 1 Powder indexes of ternary precursors obtained in Examples and Comparative Examples

[0105] <![CDATA[BET(m 2 / g)]]> <![CDATA[TD(g / cm 3 )]]> Peak intensity ratio I001 / I101 Grain size D001 (nm) Example 1 21 0.60 1.40 18 Example 2 22 0.76 0.96 16 Example 3 20 0.58 1.42 19 Example 4 30 0.92 1.15 15 Example 5 25 0.75 1.30 16 Comparative Example 1 17 1.08 0.75 17 Comparative Example 2 36 1.03 1.00 14 Comparative Example 3 30 1.72 1.35 14 Comparative Example 4 6.03 0.82 1.50 30

[0106] Test Example 2

[0107] This example tests the electrochemical properties of the lithium-ion battery obtained in Application Example 2. The test method is as follows: at 25°C, the charge and discharge cycle characteristics of the above-mentioned button battery are tested using a blue electric test cabinet. The charge and discharge test is performed at a charge and discharge rate of 0.1C (1C = 210mA / g) in the voltage range of 2.8V to 4.3V. The test results are shown in Table 1.

[0108] Table 1 Electrochemical properties of single crystal ternary cathode materials made from nanosheet-like ternary precursors obtained in Examples and Comparative Examples

[0109] 0.1C first discharge capacity (mAh / g) 0.1C cycle 100 weeks retention rate (%) Example 1 224.5 94.5 Example 2 224.1 94.0 Example 3 222.5 93.5 Example 4 222.2 92.5 Example 5 225.0 95.0 Comparative Example 1 219.2 90.0 Comparative Example 2 220.1 91.0 Comparative Example 3 218.5 89.5 Comparative Example 4 220.3 91.5

[0110] According to the results of the embodiments, the single-crystal ternary positive electrode material prepared by the present invention has a reversible charge and discharge capacity ≥222mAh / g, for example, it can be specifically about 224mAh / g or about 225mAh / g; the capacity retention rate of 100 weeks is ≥92%, for example, it can be specifically about 94%, 95% or about 96%.

[0111] The results of Example 1 and Comparative Example 1 show that the discharge capacity and cycle performance are improved after adding tetraammonium ethylenediaminetetraacetate.

[0112] Comparing the results of Example 1 and Comparative Example 2, it is shown that when the concentration of tetraammonium ethylenediaminetetraacetate is increased, the capacity and cycle deteriorate. The reason is that the dosage of tetraammonium ethylenediaminetetraacetate is too high, the residual carbon of the precursor is too high, and the residual lithium of the single crystal is too high.

[0113] Comparative Example 1 and Comparative Examples 3 to 4 show that, compared with polyvinyl pyrrolidone and polyvinyl alcohol surfactants, when the surfactant type is ammonium carboxylate, the capacity and cycle of the obtained single crystal ternary positive electrode material are better.

[0114] By comparing Example 1 with Examples 3-5, it can be seen that the capacity and cycle performance are improved by appropriately increasing the amount of surfactant, but when the amount of surfactant is too high, the capacity and cycle performance decrease.

[0115] Comparing Example 1 and Example 2, it is found that under the same number of carboxyl groups / amino groups, tetraammonium ethylenediaminetetraacetate has better performance, higher capacity and cycle performance.

[0116] In summary, the preparation method provided by the present invention significantly improves the electrochemical performance of the single-crystalline ternary cathode material prepared from the resulting nanosheet-shaped ternary precursor by adding a specific type of surfactant to the coprecipitation method and limiting the type of surfactant. The excellent electrochemical properties of this single-crystalline ternary cathode material significantly enhance its application in energy storage, electric vehicles, and other power battery applications.

[0117] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A method for preparing a nano-sheet ternary precursor, characterized in that: The preparation method comprises the steps of mixing a mixed solution containing a surfactant and a metal salt, an ammonia solution and an alkaline solution; The surfactant is an ammonium carboxylate surfactant; In the mixed solution, the concentration of the surfactant is 1 to 10 g / L.

2. The preparation method according to claim 1, characterized in that The surfactant includes at least one of ammonium isostearate, ammonium laurate, ammonium stearate, tetraammonium ethylenediaminetetraacetate, triethanolammonium oleate, triethanolammonium cocoyl glutamate, N-cocoyl glutamate, perfluorocarboxylic acid ammonium salt, hydrogenated ammonium rosinate and ammonium rosinate.

3. The preparation method according to claim 1 or 2, characterized in that In the mixed solution, the concentration of the surfactant is 2-9 g / L.

4. The preparation method according to claim 1 or 2, characterized in that The temperature of the mixed reaction is 40°C to 70°C; And / or, the pH of the mixed reaction is between 9 and 12.

5. The preparation method according to claim 1 or 2, characterized in that The mixing reaction is carried out in a stirring state; preferably, the stirring speed in the stirring state is 300 to 600 rpm.

6. A nanosheet-shaped ternary precursor prepared by the preparation method according to any one of claims 1 to 5, characterized in that: The chemical expression of the nanosheet ternary precursor is: Ni x Co y Mn z (OH)2, wherein 0.5≤x≤1, 0≤y≤0.5, 0≤z≤0.5, x+y+z=1.

7. The nanosheet-shaped ternary precursor according to claim 6, characterized in that: The equivalent diameter of the nano-sheet ternary precursor is 200-1000 nm.

8. The nanosheet-shaped ternary precursor according to claim 6, characterized in that: The BET of the nanosheet ternary precursor is 10 to 30 m 2 / g; And / or, the TD of the nanosheet-shaped ternary precursor is 0.3 to 1.5 g / cm 3 .

9. A single crystal ternary cathode material, characterized in that: The single crystal ternary cathode material is obtained by mixing and sintering the nanosheet-shaped ternary precursor according to any one of claims 6 to 8 and a lithium source.

10. A lithium ion battery, characterized in that: The raw materials for preparing the lithium-ion battery include the single crystal ternary positive electrode material as claimed in claim 9.

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