Doped and coated lithium-rich manganese-based positive electrode material as well as preparation method and application thereof

Abstract

The invention provides a doped and coated lithium-rich manganese-based positive electrode material as well as a preparation method and application thereof. The doped and coated lithium-rich manganese-based positive electrode material comprises a doped lithium-rich manganese-based core and a cerium oxide coating layer arranged on the surface of the doped lithium-rich manganese-based core, the doped lithium-rich manganese-based inner core comprises a lithium-rich manganese-based main body material and doping elements, and the doping elements comprise a magnesium element, a titanium element and an antimony element. The lithium-rich manganese-based positive electrode material is doped, modified and coated by using a plurality of base metal elements, and the cycle stability, the rate capability and the high-voltage performance of the positive electrode material can be remarkably improved through the synergistic effect of the plurality of elements.

Description

Technical Field

[0001] The present invention belongs to the technical field of battery materials, and relates to a doped and coated lithium-rich manganese-based cathode material, a preparation method thereof, and an application thereof. Background Art

[0002] With the rapid development of electric vehicles, portable electronic devices, and large-scale energy storage systems, the demand for lithium-ion batteries with high energy density, long cycle life, and low cost is increasing day by day. As the core component of lithium-ion batteries, the performance of cathode materials directly determines the energy density, cycle stability, and safety of the batteries. Among various cathode materials, lithium-rich manganese-based cathode materials are considered to be one of the ideal cathode materials for next-generation high-energy-density lithium-ion batteries due to their high specific capacity, low cost, and other advantages.

[0003] CN119560517A discloses a core-shell structured lithium-rich manganese-based cathode material, a preparation method thereof, and an application thereof. It prepares the core-shell structured lithium-rich manganese-based cathode material by means of a combination of rapid Joule heat treatment and surface plasma cleaning treatment, realizing the design of a bulk disordered structure with polyanion doping and a core-shell structure with surface gradient non-metal ion doping.

[0004] CN119503909A discloses a lithium-rich manganese-based cathode material and a preparation method thereof, including the following steps: (1) preparing a Mg-doped precursor; (2) synthesizing a Mg-doped cathode material; (3) synthesizing a Mg, Na-doped cathode material; (4) synthesizing a Mg, Na, Se-doped cathode material.

[0005] Although the structural stability of the lithium-rich manganese-based cathode material prepared by the above scheme is relatively high, it is difficult to balance the high-voltage performance and rate performance, and the actual application effect is poor. Summary of the Invention

[0006] The purpose of the present invention is to provide a doped and coated lithium-rich manganese-based cathode material, a preparation method thereof, and an application thereof. The present invention uses a variety of base metal elements to dope and coat the lithium-rich manganese-based cathode material. The synergistic effect of multiple elements can significantly improve the cycle stability, rate performance, and high-voltage performance of the cathode material.

[0007] To achieve the purpose of this invention, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a doped and coated lithium-rich manganese-based cathode material, which includes a doped lithium-rich manganese-based inner core and a cerium oxide coating layer provided on the surface of the doped lithium-rich manganese-based inner core;

[0009] The doped lithium-rich manganese-based inner core includes a lithium-rich manganese-based main material and doping elements, and the doping elements include magnesium element, titanium element, and antimony element.

[0010] In the present invention, magnesium, titanium, and antimony are doped as the core in the lithium-rich manganese-based cathode material. Among them, the ionic radius of magnesium is similar to that of lithium ions, which can occupy the lithium sites, inhibit the collapse of the lithium layer during cycling, and improve the structural stability of the core. The doping of titanium can inhibit the migration of transition metal ions and at the same time increase the diffusion rate of lithium ions, improving the rate performance of the material. Antimony ions can reduce the irreversible capacity loss at high voltages and also reduce the erosion of the electrolyte on the transition metals, improving the cycle life of the material. At the same time, the co-doping of the three will produce a synergistic effect, effectively inhibiting the structural phase change and the dissolution of transition metal ions during cycling, and further improving the structural stability and cycle performance of the material. In the present invention, a dense cerium oxide coating layer is coated on the surface of the doped lithium-rich manganese-based core, which can effectively inhibit the side reaction between the material and the electrolyte, reduce the interfacial impedance, and further improve the initial Coulomb efficiency and rate performance of the material.

[0011] Preferably, in the doped lithium-rich manganese-based core, the chemical formula of the lithium-rich manganese-based main material is Li 1.2 Ni x Mn y O2M z , where x + y = 1.

[0012] Preferably, based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol / %, the doping amount of the magnesium element is 0.5 mol / % to 2 mol%, for example: 0.5 mol%, 0.8 mol%, 1 mol%, 1.5 mol%, or 2 mol%, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0013] Preferably, based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol / %, the doping amount of the titanium element is 0.5 mol / % to 2 mol%, for example: 0.5 mol%, 0.8 mol%, 1 mol%, 1.5 mol%, or 2 mol%, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0014] Preferably, based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol / %, the doping amount of the antimony element is 0.1 mol / % to 0.5 mol%, for example: 0.1 mol%, 0.2 mol%, 0.3 mol%, 0.4 mol%, or 0.5 mol%, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0015] Preferably, the thickness of the cerium oxide coating layer is 5 nm to 20 nm, such as: 5 nm, 8 nm, 10 nm, 15 nm, or 20 nm, etc., not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0016] In a second aspect, the present invention provides a method for preparing the doped and coated lithium-rich manganese-based cathode material as described in the first aspect. The preparation method includes the following steps:

[0017] (1) Mix a lithium-rich manganese-based host metal source, a magnesium source, a titanium source, an antimony source, and a solvent to obtain a mixed solution, and perform spray drying on the mixed solution to obtain a precursor material;

[0018] (2) Mix the precursor material, a lithium source, and a cerium source, and perform calcination treatment to obtain the doped and coated lithium-rich manganese-based cathode material.

[0019] Preferably, the lithium-rich manganese-based host metal source in step (1) includes a nickel source and a manganese source.

[0020] Preferably, the lithium-rich manganese-based host metal source in step (1) further includes a cobalt source.

[0021] Preferably, the lithium-rich manganese-based host metal source, the magnesium source, the titanium source, and the antimony source in step (1) independently include any one or a combination of at least two of sulfates, nitrates, hydrochlorides, or acetates. Typical but non-limiting combinations include a combination of sulfates and nitrates, a combination of hydrochlorides and acetates, or a combination of nitrates and hydrochlorides, etc.

[0022] Preferably, the solvent in step (1) includes water.

[0023] Preferably, the total mass concentration of the mixed solution in step (1) is 2 mol / L to 8 mol / L, such as: 2 mol / L, 3 mol / L, 5 mol / L, 6 mol / L, or 8 mol / L, etc., not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0024] Preferably, the atomization pressure of the spray drying treatment in step (1) is 0.2 MPa to 1 MPa, such as: 0.2 MPa, 0.4 MPa, 0.6 MPa, 0.8 MPa, or 1 MPa, etc., not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0025] Preferably, the furnace temperature of the spray drying treatment in step (1) is 300 °C to 600 °C, such as: 300 °C, 350 °C, 400 °C, 500 °C, or 600 °C, etc., not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0026] Preferably, the residence time of the material in the spray drying treatment in step (1) is 5 s to 10 s, for example: 5 s, 6 s, 7 s, 8 s, 9 s, or 10 s, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0027] Preferably, the lithium source in step (2) includes lithium carbonate.

[0028] Preferably, the cerium source in step (2) includes cerium carbonate.

[0029] Preferably, the molar ratio of the precursor material, lithium source, and cerium source in step (2) is 1:(1.1 - 1.2):(0.015 - 0.03), for example: 1:1.1:0.015, 1:1.12:0.02, 1:1.15:0.025, 1:1.18:0.028, or 1:1.2:0.03, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0030] Preferably, the calcination treatment in step (2) includes a first-stage calcination and a second-stage calcination;

[0031] Preferably, the temperature of the first-stage calcination is 400 °C to 500 °C, for example: 400 °C, 420 °C, 450 °C, 480 °C, or 500 °C, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0032] Preferably, the heating rate of the first-stage calcination is 4 °C / min to 8 °C / min, for example: 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, or 8 °C / min, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0033] Preferably, the calcination time of the first-stage calcination is 5 h to 10 h, for example: 5 h, 6 h, 7 h, 8 h, 9 h, or 10 h, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0034] Preferably, the temperature of the second-stage calcination is 700 °C to 850 °C, for example: 700 °C, 720 °C, 750 °C, 800 °C, or 850 °C, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0035] Preferably, the heating rate of the second-stage calcination is 4 °C / min to 8 °C / min, for example: 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, or 8 °C / min, etc. It is not limited to the listed values, and other unlisted values within this value range are equally applicable.

[0036] Preferably, the calcination time for the second-stage calcination is 10 h to 15 h, for example: 10 h, 11 h, 12 h, 13 h, 14 h or 15 h, etc. It is not limited to the listed values, and other unlisted values within this numerical range are equally applicable.

[0037] In a third aspect, the present invention provides a lithium-ion battery, which includes the doped and coated lithium-rich manganese-based cathode material as described in the first aspect.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention uses a variety of base metal elements to dope, modify and coat the lithium-rich manganese-based cathode material. The synergistic effect of multiple elements can significantly improve the cycle stability, rate performance and high-voltage performance of the cathode material.

[0040] (2) For the battery prepared from the doped and coated lithium-rich manganese-based cathode material of the present invention, the discharge specific capacity at 0.1C can reach more than 270 mAh / g, the discharge specific capacity at 1C can reach more than 233 mAh / g, and the capacity retention rate after 300 cycles can reach more than 82%. By adjusting the addition amount of various materials, the discharge specific capacity at 0.1C of the battery prepared from the doped and coated lithium-rich manganese-based cathode material can reach more than 280 mAh / g, the discharge specific capacity at 1C can reach more than 247 mAh / g, and the capacity retention rate after 300 cycles can reach more than 88%. Detailed implementation manners

[0041] The technical solution of the present invention will be further described below through specific implementation manners. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations to the present invention.

[0042] Example 1

[0043] This example provides a doped and coated lithium-rich manganese-based cathode material, which is prepared by the following method:

[0044] (1) Weigh, Mn(CH3COO)2·4H2O, Ni(CH3COO)2·4H2O, Mg(CH3COO)2·4H2O, Ti(OC4H9)4 and Sb(CH3COO)3 according to the stoichiometric ratio, dissolve them in deionized water, stir evenly to obtain a mixed solution, and perform spray drying treatment on the mixed solution at an atomization pressure of 0.5 MPa, a furnace temperature of 450 °C, and a material residence time of 8 s to obtain a precursor powder;

[0045] (2) The precursor powder, lithium carbonate and cerium carbonate are mixed in a molar ratio of 1:1.15:0.025, and then calcined at a heating rate of 5 °C / min to 450 °C for 8 h, and then heated to 800 °C at a heating rate of 5 °C / min and calcined for 12 h to obtain a doped and coated lithium-rich manganese-based cathode material;

[0046] In the core of the doped and coated lithium-rich manganese-based cathode material, the chemical formula of the main material is Li 1.2 Mn 0.54 Ni 0.26 O2, and the doping amounts of Mg, Ti, and Sb elements are 1 mol%, 1 mol%, and 0.3 mol% respectively, and the thickness of the cerium oxide coating layer is 10 nm.

[0047] Example 2

[0048] This example provides a doped and coated lithium-rich manganese-based cathode material, and the doped and coated lithium-rich manganese-based cathode material is prepared by the following method:

[0049] (1) Weigh Mn(CH3COO)2·4H2O, Ni(CH3COO)2·4H2O, Mg(CH3COO)2·4H2O, Ti(OC4H9)4 and Sb(CH3COO)3 according to the stoichiometric ratio, dissolve them in deionized water, stir evenly to obtain a mixed solution, and perform spray drying treatment on the mixed solution at an atomizing pressure of 0.2 MPa, a furnace temperature of 600 °C, and a material residence time of 10 s to obtain a precursor powder;

[0050] (2) The precursor powder, lithium carbonate and cerium carbonate are mixed in a molar ratio of 1:1.1:0.015, and then calcined at a heating rate of 4 °C / min to 400 °C for 10 h, and then heated to 700 °C at a heating rate of 4 °C / min and calcined for 15 h to obtain a doped and coated lithium-rich manganese-based cathode material;

[0051] In the core of the doped and coated lithium-rich manganese-based cathode material, the chemical formula of the main material is Li 1.2 Mn 0.54 Ni 0.26 O2, and the doping amounts of Mg, Ti, and Sb elements are 0.5 mol%, 0.5 mol%, and 0.1 mol% respectively, and the thickness of the cerium oxide coating layer is 5 nm.

[0052] Example 3

[0053] This example provides a doped and coated lithium-rich manganese-based cathode material, and the doped and coated lithium-rich manganese-based cathode material is prepared by the following method:

[0054] (1) Weigh out Mn(CH3COO)2·4H2O, Ni(CH3COO)2·4H2O, Mg(CH3COO)2·4H2O, Ti(OC4H9)4 and Sb(CH3COO)3 according to the stoichiometric ratio, dissolve them in deionized water, stir evenly to obtain a mixed solution, and perform spray drying on the mixed solution at an atomization pressure of 1 MPa, a furnace temperature of 300 °C, and a residence time of 5 s for the material to obtain precursor powder;

[0055] (2) Mix the precursor powder, lithium carbonate and cerium carbonate in a molar ratio of 1:1.2:0.03, then calcine at a heating rate of 8 °C / min to 500 °C for 5 h, and then calcine at a heating rate of 8 °C / min to 850 °C for 10 h to obtain a doped and coated lithium-rich manganese-based cathode material;

[0056] In the core of the doped and coated lithium-rich manganese-based cathode material, the chemical formula of the main material is Li 1.2 Mn 0.54 Ni 0.26 O2, the doping amounts of Mg, Ti, and Sb elements are 2 mol%, 2 mol%, and 0.5 mol% respectively, and the thickness of the cerium oxide coating layer is 20 nm.

[0057] Example 4

[0058] The difference between this example and Example 1 is only that the doping amount of magnesium element is 0.3 mol / %, and other conditions and parameters are exactly the same as those in Example 1.

[0059] Example 5

[0060] The difference between this example and Example 1 is only that the doping amount of magnesium element is 3 mol / %, and other conditions and parameters are exactly the same as those in Example 1.

[0061] Example 6

[0062] The difference between this example and Example 1 is only that the doping amount of titanium element is 0.3 mol / %, and other conditions and parameters are exactly the same as those in Example 1.

[0063] Example 7

[0064] The difference between this example and Example 1 is only that the doping amount of titanium element is 3 mol / %, and other conditions and parameters are exactly the same as those in Example 1.

[0065] Example 8

[0066] The difference between this example and Example 1 is only that the doping amount of antimony element is 0.05 mol / %, and other conditions and parameters are exactly the same as those in Example 1.

[0067] Example 9

[0068] The difference between this embodiment and Embodiment 1 is only that the doping amount of antimony element is 0.8 mol / %, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0069] Embodiment 10

[0070] The difference between this embodiment and Embodiment 1 is only that the molar ratio of cerium carbonate to precursor powder is 0.04:1, and the thickness of the cerium oxide coating layer prepared is 25 nm, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0071] Embodiment 11

[0072] The difference between this embodiment and Embodiment 1 is only that the molar ratio of cerium carbonate to precursor powder is 0.01:1, and the thickness of the cerium oxide coating layer prepared is 3 nm, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0073] Comparative Example 1

[0074] The difference between this comparative example and Embodiment 1 is only that magnesium is not doped, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0075] Comparative Example 2

[0076] The difference between this comparative example and Embodiment 1 is only that titanium is not doped, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0077] Comparative Example 3

[0078] The difference between this comparative example and Embodiment 1 is only that antimony is not doped, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0079] Comparative Example 4

[0080] The difference between this comparative example and Embodiment 1 is only that cerium oxide is not coated, and other conditions and parameters are exactly the same as those in Embodiment 1.

[0081] Performance test:

[0082] The lithium-rich manganese-based cathode materials prepared in the examples and comparative examples were respectively mixed with polyvinylidene fluoride (PVDF) and acetylene black in a mass ratio of 80:10:10, added with N-methylpyrrolidone (NMP), and stirred to make a slurry; the slurry was coated on an aluminum current collector and dried at 120 °C to make a positive electrode sheet; a metal lithium sheet was used as the negative electrode sheet; the separator was an imported polypropylene microporous membrane (Celgard 2400); the electrolyte was 1 mol / L LiPF6 and ethylene carbonate (EC) + ethyl methyl carbonate (EMC) (volume ratio 3:7), and a CR2032 button-type experimental battery was assembled in a glove box and subjected to performance testing. The test results are shown in Table 1:

[0083] Table 1

[0084]

[0085] As can be seen from Table 1, it can be obtained from Examples 1-11 that for the battery prepared from the doped and coated lithium-rich manganese-based cathode material of the present invention, the 0.1C discharge specific capacity can reach more than 270 mAh / g, the 1C discharge specific capacity can reach more than 233 mAh / g, and the capacity retention rate after 300 cycles can reach more than 82%. By adjusting the addition amounts of various materials, the 0.1C discharge specific capacity of the battery prepared from the doped and coated lithium-rich manganese-based cathode material can reach more than 280 mAh / g, the 1C discharge specific capacity can reach more than 247 mAh / g, and the capacity retention rate after 300 cycles can reach more than 88%.

[0086] From the comparison between Example 1 and Examples 4-5, it can be obtained that in the core of the doped and coated lithium-rich manganese-based cathode material of the present invention, the doping amount of magnesium element will affect its performance. When the doping amount of magnesium element is controlled at 0.5 mol / % - 2 mol / %, the performance of the prepared doped and coated lithium-rich manganese-based cathode material is better. If the doping amount of magnesium is too low, it cannot effectively inhibit the migration of transition metal ions to the Li site, resulting in insufficient stability of the layered structure and easy structural collapse during the cycling process, affecting the cycling performance. If the doping amount of magnesium is too high, it may occupy too many Li sites and hinder the + diffusion, reducing the capacity.

[0087] From the comparison between Example 1 and Examples 6-7, it can be obtained that in the core of the doped and coated lithium-rich manganese-based cathode material of the present invention, the doping amount of titanium element will affect its performance. When the doping amount of titanium element is controlled at 0.5 mol / % - 2 mol / %, the performance of the prepared doped and coated lithium-rich manganese-based cathode material is better. If the doping amount of titanium is too low, it cannot fully optimize the Ni valence state and improve the electronic conductivity, resulting in increased polarization. If the doping amount of titanium is too high, it may form an inactive phase, reducing the proportion of active materials and reducing the capacity.

[0088] From the comparison between Example 1 and Examples 8-9, it can be obtained that in the core of the doped and coated lithium-rich manganese-based cathode material of the present invention, the doping amount of antimony element will affect its performance. When the doping amount of antimony element is controlled at 0.1 mol / % - 0.5 mol / %, the performance of the prepared doped and coated lithium-rich manganese-based cathode material is better. If the doping amount of antimony is too low, it cannot effectively refine the primary particles or form a radially arranged microstructure, resulting in insufficient mechanical stability. If the doping amount of antimony is too high, it may introduce too many defects and hinder the + transport.

[0089] Comparing Example 1 with Examples 10 - 11, it can be seen that during the preparation process of the doped and coated lithium-rich manganese-based cathode material of the present invention, the addition amount of the cerium source will affect its performance. Controlling the molar ratio of the cerium source to the precursor material at (0.015 - 0.03):1 results in better performance of the prepared doped and coated lithium-rich manganese-based cathode material. If the addition amount of the cerium source is too low, the electrolyte cannot be completely isolated from the cathode surface, and the CEI layer is still unstable. If the addition amount of the cerium source is too high, it will hinder the diffusion of Li + ions, increase the interfacial impedance, and reduce the rate performance.

[0090] Comparing Example 1 with Comparative Example 1, it can be seen that the present invention dopes magnesium in the lithium-rich manganese-based cathode material. The ionic radius of magnesium is similar to that of lithium ions, which can occupy the lithium sites, inhibit the collapse of the lithium layer during cycling, and improve the stability of the core structure.

[0091] Comparing Example 1 with Comparative Example 2, it can be seen that the present invention dopes titanium in the lithium-rich manganese-based cathode material. The doping of titanium can inhibit the migration of transition metal ions and at the same time increase the diffusion rate of lithium ions, improving the rate performance of the material.

[0092] Comparing Example 1 with Comparative Example 3, it can be seen that the present invention dopes antimony in the lithium-rich manganese-based cathode material. Antimony ions can reduce the irreversible capacity loss at high voltages and also reduce the erosion of the electrolyte on the transition metals, improving the cycle life of the material.

[0093] Comparing Example 1 with Comparative Example 4, it can be seen that the present invention coats a dense cerium oxide coating layer on the surface of the doped lithium-rich manganese-based core, which can effectively inhibit the side reaction between the material and the electrolyte, reduce the interfacial impedance, and further improve the first Coulomb efficiency and rate performance of the material.

[0094] The applicant declares that the above description is only the specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A doped and coated lithium-rich manganese-based cathode material, characterized in that, The doped-coated lithium-rich manganese-based cathode material includes a doped lithium-rich manganese-based core and a cerium oxide coating layer provided on the surface of the doped lithium-rich manganese-based core; The doped lithium-rich manganese-based core includes a lithium-rich manganese-based main material and doping elements, and the doping elements include magnesium element, titanium element and antimony element.

2. The doped and coated lithium-rich manganese-based cathode material according to claim 1, wherein In the doped lithium-rich manganese-based core, the chemical formula of the lithium-rich manganese-based host material is Li 1.2 Ni x Mn y O2, where x + y = 1.

3. The doped and coated lithium-rich manganese-based cathode material according to claim 1 or 2, characterized in that, Based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol%, the doping amount of the magnesium element is 0.5 mol% to 2 mol%; Preferably, based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol%, the doping amount of the titanium element is 0.5 mol% to 2 mol%; Preferably, based on the total molar amount of the doped lithium-rich manganese-based core being 100 mol%, the doping amount of the antimony element is 0.1 mol% to 0.5 mol%.

4. The doped and coated lithium-rich manganese-based cathode material according to any one of claims 1 to 3, characterized in that, The thickness of the cerium oxide coating layer is 5 nm to 20 nm.

5. A method for preparing the doped and coated lithium-rich manganese-based cathode material according to any one of claims 1-4, characterized in that, The preparation method includes the following steps: (1) Mix a lithium-rich manganese-based main metal source, a magnesium source, a titanium source, an antimony source and a solvent to obtain a mixed solution, and perform spray drying on the mixed solution to obtain a precursor material; (2) Mix the precursor material, a lithium source and a cerium source, and obtain the doped-coated lithium-rich manganese-based cathode material through calcination treatment.

6. The preparation method according to claim 5, characterized in that, The lithium-rich manganese-based main metal source in step (1) includes a nickel source and a manganese source; Preferably, the lithium-rich manganese-based main metal source, magnesium source, titanium source and antimony source in step (1) independently include any one or a combination of at least two of sulfates, nitrates, hydrochlorides or acetates; Preferably, the solvent in step (1) includes water; Preferably, the total mass concentration of the mixed solution in step (1) is 2 mol / L to 8 mol / L.

7. The preparation method according to claim 5 or 6, characterized in that, The atomization pressure of the spray drying treatment in step (1) is 0.2 MPa to 1 MPa; Preferably, the furnace temperature of the spray drying treatment in step (1) is 300 °C to 600 °C; Preferably, the residence time of the material in the spray drying treatment in step (1) is 5 s to 10 s.

8. The preparation method according to any one of claims 5-7, characterized in that, The lithium source in step (2) includes lithium carbonate; Preferably, the cerium source in step (2) includes cerium carbonate; Preferably, the molar ratio of the precursor material, lithium source and cerium source in step (2) is 1:(1.1 to 1.2):(0.015 to 0.03).

9. The preparation method according to any one of claims 5-8, characterized in that, The calcination treatment in step (2) includes a first-stage calcination and a second-stage calcination; Preferably, the temperature of the first-stage calcination is 400 °C to 500 °C; Preferably, the heating rate of the first-stage calcination is 4 °C / min to 8 °C / min; Preferably, the calcination time of the first-stage calcination is 5 h to 10 h; Preferably, the temperature of the second-stage calcination is 700 °C to 850 °C; Preferably, the heating rate of the second-stage calcination is 4 °C / min to 8 °C / min; Preferably, the calcination time of the second-stage calcination is 10 h to 15 h.

10. A lithium-ion battery, characterized in that, The lithium ion battery includes the doped-coated lithium-rich manganese-based cathode material according to any one of claims 1-4.

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