CN116247192A - Ternary positive electrode material with core-shell double-coating structure and preparation method thereof - Google Patents

Ternary positive electrode material with core-shell double-coating structure and preparation method thereof Download PDF

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CN116247192A
CN116247192A CN202310182035.0A CN202310182035A CN116247192A CN 116247192 A CN116247192 A CN 116247192A CN 202310182035 A CN202310182035 A CN 202310182035A CN 116247192 A CN116247192 A CN 116247192A
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core
ternary
shell
positive electrode
nickel
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汪宇
魏宽婷
郑刚
林浩
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Hefei Gotion High Tech Power Energy Co Ltd
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Hefei Guoxuan High Tech Power Energy Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
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    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
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Abstract

The invention relates to a ternary positive electrode material with a core-shell double-coating structure, which is formed by coating MoS on the surface 2 The low-nickel ternary positive electrode material of the coating layer is taken as a core, and the surface of the material taking the high-nickel ternary positive electrode material as a shell layer is wrapped with ZrO 2 The coating layer is obtained. According to the invention, the nickel content of the material is improved in a mode of combining the shell high nickel layer and the core, and meanwhile, the double-cladding structure has good electronic conductivity, crystal structure stability and excellent cell capacity exertion, so that the capacity exertion, multiplying power and cycle performance of the ternary lithium ion battery are improved, and the energy density of the lithium battery is also considered.

Description

Ternary positive electrode material with core-shell double-coating structure and preparation method thereof
Technical Field
The invention relates to the technical field of lithium batteries, in particular to a ternary positive electrode material with a core-shell double-coating structure and a preparation method thereof.
Background
In response to the green development strategy advocated by the country, the popularization of new energy automobiles is necessarily a trend. The endurance mileage of the automobile is an important factor of whether the automobile can be widely popularized rapidly or not, and the endurance mileage is greatly dependent on the energy density of the positive electrode material of the lithium ion battery. In recent years, nickel-cobalt-manganese ternary cathode materials are considered as the most promising next-generation high-energy lithium ion battery cathode materials due to the characteristics of high specific capacity and long cycle life, and are important for development in the industry at the present stage. However, there are general problems of the ternary nickel-cobalt-manganese material, which need to be solved. The multiplying power performance of the first ternary material and the ternary material needs to be improved, so that the quick charge performance of the ternary battery cell is improved; second,: the ternary material has too high alkali content on the surface, and residual alkali can be decomposed with electrolyte to generate hydrogen fluoride, so that metal ions are corroded, a surface structure is formed to collapse, and the cycle performance is deteriorated.
The surface coating can effectively improve the structural stability of the material, and can form a protective layer to isolate active substances in the material from electrolyte, so that side reactions at an electrode/electrolyte interface can be greatly reduced. However, although the existing coating material can effectively relieve the dissolution of metal ions and improve the cycle performance of the battery, the thicker coating layer reduces the overall energy density of the lithium battery on one hand, and the multiplying power performance of the ternary material is not obviously improved on the other hand. Therefore, the electronic conductivity of the coating substance is considered while the interface reaction is reduced, so that the multiplying power and the cycle performance of the ternary material can be better improved.
Disclosure of Invention
The invention provides a ternary positive electrode material with a core-shell double-coating structure and a preparation method thereof, which are based on the technical problems that the existing coating material in the background technology can effectively relieve the dissolution of metal ions and improve the cycle performance of a battery, but a thicker coating layer reduces the overall energy density of a lithium battery on one hand and obviously improves the multiplying power performance of the ternary material on the other hand.
The invention provides a ternary positive electrode material with a core-shell double-coating structure, wherein the ternary positive electrode material is formed by coating MoS on the surface 2 The low-nickel ternary positive electrode material of the coating layer is taken as a core, and the surface of the material taking the high-nickel ternary positive electrode material as a shell layer is wrapped with ZrO 2 The coating layer is obtained.
In a preferred embodiment of the present invention, the MoS 2 The mass of the coating layer is 0.5-1.5wt% of the mass of the ternary positive electrode material.
In a preferred embodiment of the present invention, the mass of the high nickel ternary cathode material is 35-45wt% of the mass of the ternary cathode material.
In a preferred embodiment of the present invention, the ZrO 2 The mass of the coating layer is 1-3wt% of the mass of the ternary positive electrode material.
The invention also provides a preparation method of the ternary anode material with the core-shell double-coating structure, which comprises the following steps:
s1, preparing surface-coated MoS 2 Low nickel ternary material of (2): dissolving sodium molybdate, thioacetamide and hydrated silicotungstic acid in deionized water to obtain a reaction solution A, and dispersing a low-nickel ternary material in the reaction solution A to obtain a mixed solution A; transferring the mixed solution A into a reaction kettle for hydrothermal reaction to obtain a low-nickel ternary material with the surface coated with MoS2 nano sheets;
s2, preparing a high-nickel ternary anode material shell layer: niSO is carried out 4 ·6H 2 O、CoSO 4 ·7H 2 O、MnSO 4 ·H 2 O is dissolved in deionized water to obtain a reaction solution B, and then the surface prepared by S1 is coated with MoS 2 Dispersing the low-nickel ternary material in the reaction solution B to obtain a mixed solution B, adding an alkali solution into the mixed solution B, and fully reacting in a protective atmosphere to obtain a core-shell structure precursor with a high-nickel ternary material shell layer;
s3, zr (OH) for preparing shell 4 Coating layer: dispersing the core-shell structure ternary material precursor obtained in the step S2 and a zirconium source in deionized water together, ageing the fully reacted slurry to obtain mixed slurry, washing and drying the mixed slurry in sequence, and forming Zr (OH) at the outermost layer of the core-shell structure precursor 4 A coating layer;
s4, preparing a ternary anode material with a core-shell double-coating structure: and (3) mixing the product obtained in the step (S3) with a lithium source to obtain a mixed material, sintering the mixed material in an oxygen atmosphere, crushing, sieving and demagnetizing to obtain a final product, namely the ternary anode material with the core-shell double-coating structure.
In a preferred embodiment of the present invention, in step S1, the molar ratio of sodium molybdate, thioacetamide, and hydrated silicotungstic acid is 1:6:1;
and/or the chemical formula of the low-nickel ternary material is LiNi 0.6 Co 0.05 Mn 0.35 O 2 The mass ratio of the low-nickel ternary material to the deionized water is 1:3;
and/or the temperature of the hydrothermal reaction is 200-280 ℃ and the time is 12-36h.
In a preferred embodiment of the present invention, in step S2, the reaction solution B: the mol ratio of Ni, co and Mn is 80:5:15;
and/or the alkali solution is NaOH and ammonia water solution;
and/or the chemical formula of the core-shell structure precursor with the high-nickel ternary material shell layer is (LiNi 0.6 Co 0.05 Mn 0.35 O 2 @MoS 2 ) 0.6 (Ni 0.8 Co 0.05 Mn 0.15 (OH) 2 ) 0.4 。
In a preferred embodiment of the present invention, in step S3, the mass ratio of the precursor of the core-shell structure with the high-nickel ternary material shell layer to deionized water is 1:10;
and/or the zirconium source is Zr (SO) 4 ) 2 The mass ratio of the zirconium source to the low-nickel ternary material is 1:50;
and/or, the aging is carried out at room temperature, and the aging time is 1-3h.
In a preferred embodiment of the present invention, in step S4, the lithium source is LiOH;
and/or the molar ratio of the total amount of nickel, cobalt and manganese to lithium in the mixed material is 1:1.05.
In a preferred embodiment of the present invention, in step S4, the sintering process is performed at a temperature of 700-900 ℃ for a time of 4-6 hours.
Compared with the prior art, the invention has the beneficial effects that:
1. the ternary positive electrode material with the core-shell double-coating structure improves the nickel content of the material in a mode of combining a shell high nickel layer with a core, and meanwhile, the double-coating structure has good electronic conductivity, crystal structure stability and excellent cell capacity exertion, so that the capacity exertion, multiplying power and cycle performance of a ternary lithium ion battery are improved, and meanwhile, the energy density of the lithium battery is considered. Coating a MoS layer on the surface of the core of the low-nickel ternary positive electrode material 2 Can stabilize the crystal structure of the low-nickel ternary positive electrode material, moS 2 The electrolyte also has excellent conductivity, can improve the efficiency of the transmission of electrons and lithium ions between the electrode and the electrolyte, and improves the rate capability of the ternary material; in addition, the high-nickel ternary positive electrode material of the shell layer and the core are combined, so that the nickel content of the whole ternary positive electrode material can be effectively increased, and the capacity performance of the lithium ion battery is further improved; at the same time, a layer of ZrO is coated on the surface of the shell layer 2 The corrosion of HF to transition metal can be effectively reduced, the structural change of the material in the charge-discharge process is relieved, and the electrochemical reaction environment of the high nickel layer is optimized, so that the capacity and the cycle performance of the ternary lithium ion battery are improved.
2. The method adopts an in-situ generation method to grow MoS on the surface of the low-nickel ternary positive electrode material 2 The nano sheet is then deposited with a layer of high-nickel ternary anode material on the surface of the material by utilizing a liquid phase coprecipitation method, and a layer of ZrO is coated outside the high-nickel layer 2 The prepared ternary positive electrode material with the core-shell double-coating structure has excellent capacity performance and good multiplying power and cycle performance.
Drawings
FIG. 1 is a scanning electron microscope image of a ternary positive electrode material with a core-shell double-coating structure prepared in example 4 of the present invention;
FIG. 2 is a graph of the performance of the batteries of the test and control groups according to the present invention;
FIG. 3 is a graph of the normal temperature cycle performance of the test and control cells of the present invention;
fig. 4 is a graph showing the discharge curves of the cells of the test and control groups according to the present invention.
Detailed Description
The invention provides a ternary positive electrode material with a core-shell double-coating structure, which is formed by coating MoS on the surface 2 The low-nickel ternary positive electrode material of the coating layer is taken as a core, and the surface of the material taking the high-nickel ternary positive electrode material as a shell layer is wrapped with ZrO 2 The coating layer is obtained.
Wherein MoS 2 The mass of the coating layer is 0.5-1.5wt% of the mass of the ternary positive electrode material. The mass of the high-nickel ternary positive electrode material is 35-45wt% of the mass of the ternary positive electrode material. ZrO (ZrO) 2 The mass of the coating layer is 1-3wt% of the mass of the ternary positive electrode material.
The invention also provides a preparation method of the ternary positive electrode material with the core-shell double-coating structure, which comprises the following steps:
s1, preparing surface-coated MoS 2 Low nickel ternary material of (2): dissolving sodium molybdate, thioacetamide and hydrated silicotungstic acid in deionized water to obtain a reaction solution A, and dispersing a low-nickel ternary material in the reaction solution A to obtain a mixed solution A; transferring the mixed solution A into a reaction kettle for hydrothermal reaction to obtain a low-nickel ternary material with the surface coated with MoS2 nano sheets;
s2, preparing a high-nickel ternary anode material shell layer: niSO is carried out 4 ·6H 2 O、CoSO 4 ·7H 2 O、MnSO 4 ·H 2 O is dissolved in deionized water to obtain a reaction solution B, and then the surface prepared by S1 is coated with MoS 2 Dispersing the low-nickel ternary material in the reaction solution B to obtain a mixed solution B, adding an alkali solution into the mixed solution B, and fully reacting in a protective atmosphere to obtain a core-shell structure precursor with a high-nickel ternary material shell layer;
s3, zr (OH) for preparing shell 4 Coating layer: dispersing the core-shell structure ternary material precursor obtained in the step S2 and a zirconium source in deionized water together, ageing the fully reacted slurry to obtain mixed slurry, washing and drying the mixed slurry in sequence, and forming Zr (OH) at the outermost layer of the core-shell structure precursor 4 A coating layer;
s4, preparing a ternary anode material with a core-shell double-coating structure: and (3) mixing the product obtained in the step (S3) with a lithium source to obtain a mixed material, sintering the mixed material in an oxygen atmosphere, crushing, sieving and demagnetizing to obtain a final product, namely the ternary anode material with the core-shell double-coating structure.
The invention will be further illustrated with reference to examples. All materials, chemicals used in the examples below are commercially available products.
Example 1
The embodiment provides a preparation method of a ternary positive electrode material with a core-shell double-coating structure, which comprises the following steps:
s1, preparing surface-coated MoS 2 Low nickel ternary material of (2):
1mol (Na 2 MoO 4 ·H 2 O), 6mol of thioacetamide (C 2 H 5 NS) and 1mol of hydrated silicotungstic acid are dissolved in deionized water to obtain a reaction solution A, and then 4kg of low-nickel ternary material LiNi 0.6 Co 0.05 Mn 0.35 O 2 Dispersing in the reaction liquid A, and continuously stirring for 2 hours to obtain a mixed liquid A, wherein the mass ratio of the low-nickel ternary material to the deionized water is 1:3. The mixture A was then transferred to a reaction kettle and heated at 240℃for 24h. Vacuum-filtering, washing, and vacuum-drying the precipitate in 100deg.C oven for 6 hr to obtain surface-coated MoS 2 Low nickel ternary material of nano sheet.
S2, preparing a high-nickel ternary anode material shell layer:
NiSO is carried out 4 ·6H 2 O、CoSO 4 ·7H 2 O、MnSO 4 ·H 2 O is dissolved in deionized water to obtain a reaction liquid B (Ni: co: mn=80:5:15), and then the surface prepared in S1 is coated with MoS 2 Dispersing the low-nickel ternary material in the reaction solution to obtain a mixed solution B, adding sodium hydroxide and ammonia water into the mixed solution B, and adding the mixed solution B into the mixed solution B to obtain a mixed solution B 2 Fully reacting in the atmosphere to obtain a core-shell structure precursor (LiNi) with a high-nickel ternary material shell layer 0.6 Co 0.05 Mn 0.35 O 2 @MoS 2 ) 0.6 (Ni 0.8 Co 0.05 Mn 0.15 (OH) 2 ) 0.4 。
S3, zr (OH) for preparing shell 4 Coating layer:
dispersing the core-shell structure precursor obtained in the step S2 in deionized water, wherein the mass ratio of the core-shell structure precursor to the deionized water is 1:10. Subsequently the zirconium source Zr (SO) 4 ) 2 Adding deionized water, fully reacting, aging the obtained slurry for 3 hours at room temperature, washing with pure water until the pH value of the washing water is less than 8, and drying to form Zr (OH) at the outermost layer of the ternary material precursor 4 A coating layer; wherein Zr (SO) 4 ) 2 The mass ratio of the cathode material to the ternary cathode material is 1:50.
S4, preparing a ternary anode material with a core-shell double-coating structure:
and (3) mixing the product obtained in the step (S3) with a lithium source LiOH to obtain a mixed material, wherein the molar ratio of the total amount of nickel, cobalt and manganese to lithium in the mixed material is 1:1.05. And (3) sending the mixed material into a sintering furnace at 800 ℃ under the oxygen atmosphere for sintering treatment for 5 hours, crushing, sieving and demagnetizing to obtain a final product, namely the ternary positive electrode material with the core-shell double-coating structure, and then carrying out mixing on the mixed material.
Example 2
The present embodiment provides a method for preparing a ternary cathode material having a core-shell double-coating structure, which is substantially similar to the method for preparing a ternary cathode material having a core-shell double-coating structure described in embodiment 1, except that in step S1 of the present embodiment, a low-nickel ternary material LiNi 0.6 Co 0.05 Mn 0.35 O 2 The amount of the catalyst was 5kg.
Example 3
The present embodiment provides a method for preparing a ternary cathode material having a core-shell double-coating structure, which is substantially similar to the method for preparing a ternary cathode material having a core-shell double-coating structure described in embodiment 1, except that in step S1 of the present embodiment, a low-nickel ternary material LiNi 0.6 Co 0.05 Mn 0.35 O 2 The amount of the catalyst was 6kg.
Example 4
The present embodiment provides a method for preparing a ternary cathode material with a core-shell double-coating structure, which is substantially similar to the method for preparing a ternary cathode material with a core-shell double-coating structure described in embodiment 1, except that in step S1 of this embodiment: low-nickel ternary material LiNi 0.6 Co 0.05 Mn 0.35 O 2 The amount of (2) added was 5kg, and in step S4: the sintering temperature was 850 ℃.
The low-nickel ternary cathode material is used as a blank comparative example, and the low-nickel ternary cathode material and the ternary cathode material with the core-shell double-coating structure in the embodiment 4 are respectively used under the condition of the same active material ratio to prepare corresponding ternary lithium ion batteries, namely a control group and a test group. The two groups of lithium ion batteries are the same in other materials except for the positive electrode material, the consumption and the battery preparation method. The following are the test results for the cell performance of the control and test groups, two groups for each cell in parallel:
(1) Battery double charging performance test
The specific test method comprises the following steps: taking a test group battery and a control group battery, respectively charging the test group battery and the control group battery from 2.8V constant current to 4.25V at 0.33C/0.5C/1C/2C/3C/4C/5C, keeping constant voltage charging of 4.25V, and stopping current at 0.05C; then discharging to 2.8V at 1C, and sequentially recording constant current charging ratios under different multiplying powers, wherein test results are shown in Table 1 and FIG. 2.
Table 1 constant current charge ratio corresponding to different rates of test and control cells
Figure BDA0004102615120000071
As can be seen from table 1 and fig. 2, under the condition of high-rate discharge, the constant current charging ratio corresponding to the test group battery is obviously better than that of the control group battery, and when the test group battery is charged at 5C rate, the constant current charging ratio of the test group still reaches more than 60%; therefore, the ternary positive electrode material with the core-shell double-coating structure, which is prepared by the invention, can be applied to a lithium ion battery, and the quick charge performance of the battery is greatly improved.
(2) Testing of normal temperature cycle performance of battery
The specific test method comprises the following steps: taking a test group battery and a control group battery, charging the test group battery and the control group battery from 2.8V constant current to 4.25V constant current at 0.5C, and keeping constant voltage charging at 4.25V, wherein the cut-off current is 0.05C; then discharging to 2.8V with 1C constant current, and circularly charging and discharging for 2000 weeks in the process step, wherein the test results are shown in Table 2 and FIG. 3.
Table 2 capacity retention rates for test and control cells
Figure BDA0004102615120000081
As can be seen from table 2 and fig. 3, the control battery current cycle 1700 Zhou Zuo is about 82.00% in capacity retention; when the test battery is cycled for more than 2000 weeks, the capacity retention rate can still reach more than 88.0 percent; therefore, the ternary positive electrode material with the core-shell double-coating structure prepared by the method is applied to the lithium ion battery, and the normal-temperature cycle performance of the battery is obviously improved.
(3) Battery capacity performance test
The specific test method comprises the following steps: taking a test group battery and a control group battery, charging the test group battery and the control group battery from 2.8V constant current to 4.25V, keeping constant voltage charging of 4.25V, and stopping current at 0.05C; then the discharge was carried out again at a constant current of 1C to 2.8V, and the test results are shown in Table 3 and FIG. 4.
TABLE 3 discharge capacities of test and control cells
Figure BDA0004102615120000082
As can be seen from table 3 and fig. 4, the capacity of the test group cell prepared by the identical cell process is significantly higher than that of the control group cell, so that the capacity exertion of the lithium ion battery can be effectively improved by the preparation method of combining the high-nickel layer of the shell and the core.
In conclusion, the ternary positive electrode material with the core-shell double-coating structure prepared by the method has excellent capacity performance and good multiplying power and cycle performance.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (10)

1. A ternary positive electrode material with a core-shell double-coating structure is characterized in that the ternary positive electrode material is formed by coating MoS on the surface 2 The low-nickel ternary positive electrode material of the coating layer is taken as a core, and the surface of the material taking the high-nickel ternary positive electrode material as a shell layer is wrapped with ZrO 2 The coating layer is obtained.
2. The ternary cathode material of core-shell structure of claim 1, wherein the MoS 2 The mass of the coating layer is 0.5-1.5wt% of the mass of the ternary positive electrode material.
3. The ternary cathode material of a core-shell structure according to claim 1, wherein the mass of the high-nickel ternary cathode material is 35-45wt% of the mass of the ternary cathode material.
4. The ternary cathode material of a core-shell structure according to claim 1, wherein the ZrO 2 The mass of the coating layer is 1-3wt% of the mass of the ternary positive electrode material.
5. A method for preparing the ternary cathode material with the core-shell double-coating structure according to any one of claims 1 to 4, comprising the following steps:
s1, preparing surface-coated MoS 2 Low nickel ternary material of (2): dissolving sodium molybdate, thioacetamide and hydrated silicotungstic acid in deionized water to obtain a reaction solution A, and dispersing a low-nickel ternary material in the reaction solution A to obtain a mixed solution A; transferring the mixed solution A into a reaction kettle for hydrothermal reaction to obtain surface-coated MoS 2 A low nickel ternary material of the nanoplatelets;
s2, preparing a high-nickel ternary anode material shell layer: niSO is carried out 4 ·6H 2 O、CoSO 4 ·7H 2 O、MnSO 4 ·H 2 O is dissolved in deionized water to obtain a reaction solution B, and then the surface prepared by S1 is coated with MoS 2 Dispersing the low-nickel ternary material in the reaction solution B to obtain a mixed solution B, adding an alkali solution into the mixed solution B, and fully reacting in a protective atmosphere to obtain a core-shell structure precursor with a high-nickel ternary material shell layer;
s3, zr (OH) for preparing shell 4 Coating layer: dispersing the core-shell structure precursor with the high-nickel ternary material shell layer obtained in the step S2 and a zirconium source in deionized water together, ageing the fully reacted slurry to obtain mixed slurry, washing and drying the mixed slurry in sequence, and forming Zr (OH) at the outermost layer of the core-shell structure precursor 4 A coating layer;
s4, preparing a ternary anode material with a core-shell double-coating structure: and (3) mixing the product obtained in the step (S3) with a lithium source to obtain a mixed material, sintering the mixed material in an oxygen atmosphere, crushing, sieving and demagnetizing to obtain a final product, namely the ternary anode material with the core-shell double-coating structure.
6. The preparation method of the ternary cathode material with the core-shell double-coating structure, which is characterized in that in the step S1, the molar ratio of sodium molybdate to thioacetamide to hydrated silicotungstic acid is 1:6:1;
and/or the chemical formula of the low-nickel ternary material is LiNi 0.6 Co 0.05 Mn 0.35 O 2 The mass ratio of the low-nickel ternary material to the deionized water is 1:3;
and/or the temperature of the hydrothermal reaction is 200-280 ℃ and the time is 12-36h.
7. The method for preparing a ternary positive electrode material with a core-shell double-coating structure according to claim 5, wherein in step S2, the reaction solution B is: the mol ratio of Ni, co and Mn is 80:5:15;
and/or the alkali solution is NaOH and ammonia water solution;
and/or the chemical formula of the core-shell structure precursor with the high-nickel ternary material shell layer is (LiNi 0.6 Co 0.05 Mn 0.35 O 2 @MoS 2 ) 0.6 (Ni 0.8 Co 0.05 Mn 0.15 (OH)2) 0.4 。
8. The method for preparing a ternary positive electrode material with a core-shell double-coating structure according to claim 5, wherein in the step S3, the mass ratio of the core-shell structure precursor with the high-nickel ternary material shell layer to deionized water is 1:10;
and/or the zirconium source is Zr (SO) 4 ) 2 The mass ratio of the zirconium source to the low-nickel ternary material is 1:50;
and/or, the aging is carried out at room temperature, and the aging time is 1-3h.
9. The method for preparing a ternary positive electrode material with a core-shell double-coating structure according to claim 5, wherein in the step S4, the lithium source is LiOH;
and/or the molar ratio of the total amount of nickel, cobalt and manganese to lithium in the mixed material is 1:1.05.
10. The method for preparing a ternary positive electrode material with a core-shell double-coating structure according to claim 5, wherein in the step S4, the sintering treatment is performed at a temperature of 700-900 ℃ for 4-6 hours.
CN202310182035.0A 2023-02-24 2023-02-24 Ternary positive electrode material with core-shell double-coating structure and preparation method thereof Pending CN116247192A (en)

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