Composite coated ternary positive electrode material and preparation method and application thereof

Abstract

The invention relates to the technical field of lithium ion batteries, and discloses a composite coated ternary positive electrode material as well as a preparation method and application thereof. According to the composite coated ternary positive electrode material provided by the invention, the antimony element is doped in the matrix, so that the crystal structure can be stabilized by Sb < 5 + > with high valence and large ion radius, and the mixed arrangement of cations is reduced; the cobalt and lithium elements of the first coating layer can form a stable spinel structure on the surface of a matrix, and interface side reaction is inhibited; surface coating of the tungsten element, the aluminum element, the titanium element and the zirconium element inhibits interface side reaction, the structural stability of the positive electrode material is improved, and the cycling stability and the thermal stability of the lithium ion battery are further improved.

Description

Technical Field

[0001] This invention relates to the field of lithium-ion battery technology, specifically to a composite-coated ternary cathode material, its preparation method, and its application. Background Technology

[0002] As the application of lithium-ion batteries in the field of new energy vehicles gradually expands, driving range has become a key factor restricting the development of new energy vehicles, and improving the energy density of lithium-ion batteries is an effective way to solve range anxiety.

[0003] The high-voltage approach increases the battery's charging cutoff voltage, allowing the cathode material to release more lithium ions at higher voltages, thus simultaneously improving capacity and operating voltage, ultimately increasing energy density. Furthermore, because high-voltage materials have relatively low nickel content, their manufacturing process is less complex than high-nickel ternary materials, thus offering some safety improvements alongside increased energy density. However, under high-voltage (>4.4V) conditions, the large-scale release of lithium ions can cause ternary cathode materials to experience decreased crystal structure stability, disordered ion arrangement, and irreversible phase transitions, leading to shortened battery cycle life and reduced thermal stability. Existing technologies often employ methods such as metal ion doping, creating artificial protective layers, and using high-voltage electrolytes and additives to mitigate these issues, but cycle stability remains poor.

[0004] Therefore, how to optimize and adjust ternary cathode materials and their preparation methods to prepare structurally stable ternary cathode materials, thereby improving the cycle life and thermal stability of lithium-ion batteries, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] This invention provides a composite-coated ternary cathode material to solve the problems of short cycle life and poor thermal stability in existing lithium-ion batteries.

[0006] This invention also provides a method for preparing a composite-coated ternary cathode material.

[0007] In a first aspect, the present invention provides a composite coated ternary cathode material, comprising a matrix material and a coating layer covering the outer surface of the matrix material, the coating layer comprising a first coating layer and a second coating layer, wherein the first coating layer covers at least a portion of the surface of the matrix material, and the second coating layer covers at least a portion of the surface of the first coating layer; The matrix material includes antimony. The first coating layer contains cobalt and lithium; the second coating layer contains tungsten, aluminum, titanium and zirconium.

[0008] In some alternative embodiments, the cobalt content in the first coating layer is 0.1%-1.6% by mass of the matrix material.

[0009] In some alternative embodiments, the lithium content in the first coating layer is 0.1%-1.6% by mass of the matrix material.

[0010] In some alternative embodiments, the tungsten content in the second coating layer is 0.1%-0.6% by mass of the matrix material.

[0011] In some alternative embodiments, the aluminum content in the second coating layer is 0.1%-0.6% by mass of the substrate material.

[0012] In some alternative embodiments, the titanium content in the second coating layer is 0.1%-0.6% by mass of the matrix material.

[0013] In some alternative embodiments, the zirconium content in the second coating layer is 0.1%-0.6% by mass of the matrix material.

[0014] In some alternative embodiments, the chemical formula of the matrix material is Li. f (Ni a Co b Mn c Sb d M e O2, where 0.58≤a≤0.8, 0.1≤b≤0.2, 0.0003≤d≤0.007, 0.0002≤e≤0.009, a+b+c+d+e=1, 1.02≤f≤1.08, and M is at least one of zirconium, yttrium, tungsten, and niobium.

[0015] In a second aspect, the present invention provides a method for preparing the composite-coated ternary cathode material described in the first aspect, comprising the following steps: (1) The nickel-cobalt-manganese precursor, the first lithium source, and the antimony source are mixed and then subjected to the first sintering to obtain the matrix material; (2) The matrix material, cobalt source and second lithium source are mixed and then subjected to a second sintering to obtain a cobalt-lithium coated matrix material; (3) The cobalt-lithium coated matrix material, tungsten source, aluminum source, titanium source and zirconium source are mixed and then subjected to a third sintering to prepare a composite coated ternary cathode material.

[0016] In some alternative embodiments, step (1) further includes adding a dopant, said dopant including at least one of oxides of zirconium, yttrium, tungsten, and niobium.

[0017] In some alternative embodiments, the total molar number of metal elements in the matrix material to the molar ratio of metal elements in the dopant is 1:0.0002-0.009.

[0018] In some optional embodiments, the total molar number of metal elements in the matrix material to the molar ratio of antimony elements in the antimony source is 1:0.0003-0.007.

[0019] In some optional embodiments, the total molar number of metal elements in the matrix material to the molar ratio of lithium elements in the first lithium source is 1:1.02-1.08.

[0020] In some alternative embodiments, the mass of cobalt in the cobalt source accounts for 0.1%-1.6% of the mass of the matrix material.

[0021] In some alternative embodiments, the mass of lithium in the second lithium source accounts for 0.1%-1.6% of the mass of the matrix material.

[0022] In some alternative embodiments, the tungsten element in the tungsten source accounts for 0.1%-0.6% of the mass of the matrix material.

[0023] In some alternative embodiments, the mass of aluminum in the aluminum source accounts for 0.1%-0.6% of the mass of the matrix material.

[0024] In some alternative embodiments, the mass of titanium in the titanium source accounts for 0.1%-0.6% of the mass of the matrix material.

[0025] In some alternative embodiments, the zirconium element in the zirconium source accounts for 0.1%-0.6% of the mass of the matrix material.

[0026] In some optional embodiments, the chemical formula of the nickel-cobalt-manganese precursor is Ni. x Co y Mn z (OH)2, 0.6≤x≤0.8, 0.1≤y≤0.2, x+y+z=1.

[0027] In some alternative embodiments, the first lithium source includes at least one of lithium hydroxide and lithium carbonate.

[0028] In some alternative embodiments, the antimony source includes antimony oxide.

[0029] In some alternative embodiments, the cobalt source includes at least one of cobalt hydroxide, cobalt hydroxyl oxide, and cobalt tetroxide.

[0030] In some alternative embodiments, the second lithium source includes lithium hydroxide.

[0031] In some alternative embodiments, the tungsten source includes at least one of tungsten oxide, tungstic acid, and ammonium paratungstate.

[0032] In some alternative embodiments, the aluminum source includes at least one of aluminum oxide and aluminum hydroxide.

[0033] In some alternative embodiments, the titanium source includes at least one of titanium oxide and titanium hydroxide.

[0034] In some alternative embodiments, the zirconium source includes at least one of zirconium oxide, zirconium hydride, and zirconium iodide.

[0035] In some optional embodiments, the first sintering temperature is 700℃-1000℃, the time is 8h-15h, the heating rate is 1℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air.

[0036] In some optional embodiments, the second sintering temperature is 600℃-900℃, the time is 3h-7h, the heating rate is 1.5℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air.

[0037] In some optional embodiments, the third sintering temperature is 300℃-500℃, the time is 3h-7h, the heating rate is 1.5℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air.

[0038] The third invention provides a composite-coated ternary cathode material as described in the first aspect and a composite-coated ternary cathode material prepared by the preparation method described in the second aspect, and its application in lithium-ion batteries.

[0039] The technical solution of this invention has the following advantages: 1. The composite-coated ternary cathode material provided by the present invention includes a matrix material and a coating layer covering the outer surface of the matrix material. The coating layer includes a first coating layer and a second coating layer. The first coating layer covers at least a portion of the surface of the matrix material, and the second coating layer covers at least a portion of the surface of the first coating layer. The matrix material includes antimony. The first coating layer contains cobalt and lithium. The second coating layer contains tungsten, aluminum, titanium, and zirconium. The present invention alleviates cation mixing and structural degradation caused by rock salting phase transition by doping the matrix with antimony, lithium, and cobalt to form the first coating layer and with tungsten, aluminum, titanium, and zirconium to form the second coating layer. This stabilizes the lattice oxygen structure, suppresses interfacial side reactions, and improves the cycle stability and thermal stability of the composite-coated ternary cathode material. The doping with antimony in the matrix, with its high valence and large ionic radius, provides Sb... 5+ It can stabilize the crystal structure and reduce cation mixing; the cobalt and lithium elements in the first coating layer can form a stable spinel structure on the substrate surface and suppress interfacial side reactions; the surface coating of tungsten, aluminum, titanium and zirconium elements suppresses interfacial side reactions, improves the structural stability of the cathode material, and thus improves the cycle stability and thermal stability of lithium-ion batteries.

[0040] 2. The composite-coated ternary cathode material provided by the present invention, wherein the chemical formula of the matrix material is Li f (Ni a Co b Mn c Sb d M e O2, where 0.58≤a≤0.8, 0.1≤b≤0.2, a+b+c=1, 0.0003≤d≤0.007, 0.0002≤e≤0.009, 1.02≤f≤1.08, and M is at least one of zirconium, yttrium, tungsten, and niobium; doping the matrix with at least one of zirconium, yttrium, tungsten, and niobium can suppress phase transitions, and zirconium can form Zr-O bonds. 4+ During charging and discharging, the constant valence state acts as a support, improving structural stability; Y 3+ Ionic radius greater than Ni 2+ The negative Gibbs free energy of Y2O3 is greater than that of NiO strong bond energy, which reduces cation mixing; WO has a larger dissociation energy, which enhances structural stability, suppresses phase transition and polarization, reduces resistance, and improves lithium ion diffusion coefficient. Niobium doping can improve structural stability, expand interlayer spacing, and improve rate and cycle performance. Attached Figure Description

[0041] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0042] Figure 1 This is a scanning electron microscope image of the composite-coated ternary cathode material prepared in Example 1 of this invention; Figure 2 This is a scanning electron microscope image of the composite-coated ternary cathode material prepared in Example 2 of this invention; Figure 3 This is a scanning electron microscope image of the composite-coated ternary cathode material prepared in Example 3 of the present invention; Figure 4 This is a scanning electron microscope image of the composite-coated ternary cathode material prepared in Example 4 of the present invention. Detailed Implementation

[0043] The following embodiments are provided to better understand the present invention, but the following embodiments do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the scope of protection of the present invention.

[0044] Unless otherwise specified, all experimental steps or conditions in the examples were performed according to conventional experimental procedures and conditions in the art. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0045] Example 1 This embodiment provides a method for preparing a composite-coated ternary cathode material, including the following steps: (1) Ni 0.6 Co 0.1 Mn 0.3 The (OH)₂ precursor, lithium carbonate, zirconium oxide, yttrium oxide, and antimony oxide were mixed uniformly and heat-treated at 960℃ for 10 hours under an oxygen atmosphere by heating at 2.5℃ / min. The mixture was then naturally cooled to room temperature to obtain the matrix material Li. 1.04 (Ni 0.594 Co 0.1 Mn 0.3 Zr 0.001 Y 0.002 Sb 0.003O2; wherein, the ratio of the total molar amount of metal elements in the matrix material to the molar amount of lithium in lithium carbonate is 1:1.04; the molar ratio of the total molar amount of metal elements in the matrix material to zirconium in zirconium oxide, yttrium in yttrium oxide, and antimony in antimony oxide is 1:0.001:0.002:0.003; (2) Mix the matrix material, cobalt hydroxide and lithium hydroxide, wherein the amount of cobalt in cobalt hydroxide and the amount of lithium in lithium hydroxide are 1 wt% and 0.1 wt% of the mass of the matrix material, respectively. Then, sinter the mixture at 2 °C / min to 600 °C for 4 h in an air atmosphere and allow it to cool naturally to room temperature to obtain a lithium cobalt coated matrix material. (3) The lithium cobalt-coated matrix material, tungsten oxide, aluminum oxide, titanium oxide and zirconium oxide are mixed. The amount of tungsten in tungsten oxide, aluminum in aluminum oxide, titanium in titanium oxide and zirconium in zirconium oxide are 0.2wt%, 0.2wt%, 0.1wt% and 0.4wt% of the matrix material, respectively. Then, the mixture is heated to 400℃ at 2℃ / min and sintered for 4h in an oxygen atmosphere. The mixture is then cooled to room temperature naturally to obtain a composite-coated ternary cathode material. The content of cobalt and lithium in the first coating layer is 1wt% and 0.1wt%, respectively, and the content of tungsten, aluminum, titanium and zirconium in the second coating layer is 0.2wt%, 0.2wt%, 0.1wt% and 0.4wt%, respectively.

[0046] Example 2 This embodiment provides a method for preparing a composite-coated ternary cathode material, including the following steps: (1) Ni 0.7 Co 0.1 Mn 0.2 The (OH)₂ precursor, lithium hydroxide, zirconium oxide, yttrium oxide, and antimony oxide were mixed uniformly and heat-treated at 920℃ for 10 hours under an oxygen atmosphere by heating at 2.5℃ / min. The mixture was then naturally cooled to room temperature to obtain the matrix material Li. 1.06 (Ni 0.696 Co 0.1 Mn 0.2 Zr 0.001 Y 0.002 Sb 0.001 O2; wherein, the ratio of the total molar amount of metal elements in the matrix material to the molar amount of lithium in lithium hydroxide is 1:1.06; the molar ratio of the total molar amount of metal elements in the matrix material to zirconium in zirconium oxide, yttrium in yttrium oxide, and antimony in antimony oxide is 1:0.001:0.002:0.001; (2) Mix the matrix material, cobalt hydroxyoxide and lithium hydroxide, wherein the amount of cobalt in cobalt hydroxyoxide and the amount of lithium in lithium hydroxide are 1.2 wt% and 0.11 wt% of the mass of the matrix material, respectively. Then, sinter the mixture at 600 °C for 4 h in an air atmosphere at a rate of 2 °C / min, and then allow it to cool naturally to room temperature to obtain a lithium cobalt coated matrix material. (3) The lithium cobalt-coated matrix material, tungsten oxide, aluminum oxide, titanium oxide and zirconium oxide are mixed. The amount of tungsten in tungsten oxide, aluminum in aluminum oxide, titanium in titanium oxide and zirconium in zirconium oxide are 0.2wt%, 0.2wt%, 0.1wt% and 0.1wt% of the matrix material, respectively. Then, the mixture is heated to 400℃ at 2℃ / min and sintered for 4h in an oxygen atmosphere. It is then cooled to room temperature naturally to obtain a composite-coated ternary cathode material. The content of cobalt and lithium in the first coating layer is 1.2wt% and 0.11wt%, respectively, and the content of tungsten, aluminum, titanium and zirconium in the second coating layer is 0.2wt%, 0.2wt%, 0.1wt% and 0.1wt%, respectively.

[0047] Example 3 This embodiment provides a method for preparing a composite-coated ternary cathode material, including the following steps: (1) Ni 0.65 Co 0.1 Mn 0.25 The (OH)₂ precursor, lithium hydroxide, tungsten oxide, niobium oxide, and antimony oxide were mixed uniformly and heat-treated at 700℃ for 15 h under an oxygen atmosphere by heating at 5℃ / min. After natural cooling to room temperature, the matrix material Li was obtained. 1.02 (Ni 0.636 Co 0.1 Mn 0.25 W 0.003 Nb 0.006 Sb 0.005 O2; wherein, the ratio of the total molar amount of metal elements in the matrix material to the molar amount of lithium in lithium hydroxide is 1:1.02; the molar ratio of the total molar amount of metal elements in the matrix material to tungsten in tungsten oxide, niobium in niobium oxide, and antimony in antimony oxide is 1:0.003:0.006:0.005; (2) Mix the matrix material, cobalt tetroxide and lithium hydroxide, wherein the amount of cobalt in cobalt tetroxide and the amount of lithium in lithium hydroxide are 0.5 wt% and 1.6 wt% of the mass of the matrix material, respectively. Then, sinter the mixture at 750 °C for 7 h in an air atmosphere at a rate of 5 °C / min, and allow it to cool naturally to room temperature to obtain a lithium cobalt coated matrix material. (3) The lithium cobalt-coated matrix material, tungsten oxide, aluminum hydroxide, titanium hydroxide, and zirconium hydride are mixed. The amount of tungsten in tungsten oxide, aluminum in aluminum hydroxide, titanium in titanium hydroxide, and zirconium in zirconium hydride added are 0.1 wt%, 0.6 wt%, 0.3 wt%, and 0.6 wt% of the matrix material mass, respectively. Then, the mixture is sintered at 500℃ for 5 h at 4℃ / min under an oxygen atmosphere and then cooled naturally to room temperature to obtain a composite-coated ternary cathode material. The content of cobalt and lithium in the first coating layer is 0.5 wt% and 1.6 wt%, respectively, and the content of tungsten, aluminum, titanium, and zirconium in the second coating layer is 0.1 wt%, 0.6 wt%, 0.3 wt%, and 0.6 wt%, respectively.

[0048] Example 4 This embodiment provides a method for preparing a ternary cathode material, including the following steps: (1) Ni 0.8 Co 0.1 Mn 0.1 The (OH)₂ precursor, lithium hydroxide, niobium oxide, and antimony oxide were mixed uniformly and heat-treated at 1000℃ for 8 hours under an oxygen atmosphere by heating at 1℃ / min. After natural cooling to room temperature, the matrix material Li was obtained. 1.08 (Ni 0.787 Co 0.1 Mn 0.1 Nb 0.006 Sb 0.007 O2; wherein, the ratio of the total molar amount of metal elements in the matrix material to the molar amount of lithium in lithium hydroxide is 1:1.08; the mass ratio of the total molar amount of metal elements in the matrix material to the mass of niobium in niobium oxide and antimony in antimony oxide is 1:0.006:0.007; (2) Mix the matrix material, cobalt hydroxyoxide and lithium hydroxide, wherein the amount of cobalt in cobalt hydroxyoxide and the amount of lithium in lithium hydroxide are 1.6 wt% and 0.5 wt% of the mass of the matrix material, respectively. Then, sinter the mixture at 900 °C for 3 h in air atmosphere at a rate of 1.5 °C / min and allow it to cool naturally to room temperature to obtain the lithium cobalt coated matrix material. (3) The lithium cobalt-coated matrix material, tungsten oxide, aluminum oxide, titanium oxide and zirconium iodide are mixed. The amount of tungsten in tungsten oxide, aluminum in aluminum oxide, titanium in titanium oxide and zirconium in zirconium iodide added are 0.2wt%, 0.1wt%, 0.6wt% and 0.5wt% of the matrix material, respectively. Then, the mixture is heated to 300℃ at 5℃ / min and sintered for 7h in an oxygen atmosphere. It is then cooled to room temperature naturally to obtain a composite-coated ternary cathode material. The content of cobalt and lithium in the first coating layer is 1.6wt% and 0.5wt%, respectively, and the content of tungsten, aluminum, titanium and zirconium in the second coating layer is 0.2wt%, 0.1wt%, 0.6wt% and 0.5wt%, respectively.

[0049] Comparative Example 1 This comparative example provides a method for preparing a ternary cathode material, which is basically the same as the steps in Example 1, except that step (2) is omitted.

[0050] Comparative Example 2 This comparative example provides a method for preparing a ternary cathode material, which is basically the same as the steps in Example 1, except that step (3) is omitted.

[0051] Comparative Example 3 This comparative example provides a method for preparing a ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (1), the addition of antimony oxide is omitted, and the molar ratio of the total amount of metal elements in the matrix material to the molar ratio of zirconium elements in zirconium oxide is 1:0.004.

[0052] Comparative Example 4 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (2), the addition of cobalt hydroxide is omitted, and the amount of lithium added in lithium hydroxide is 1.1 wt% of the mass of the matrix material.

[0053] Comparative Example 5 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (2), the addition of lithium hydroxide is omitted, and the amount of cobalt added in cobalt hydroxide is 1.1 wt% of the mass of the matrix material.

[0054] Comparative Example 6 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (3), the addition of tungsten oxide is omitted, and the amount of aluminum added in aluminum oxide is 0.4 wt% of the mass of the matrix material.

[0055] Comparative Example 7 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (3), the addition of aluminum oxide is omitted, and the amount of tungsten element added in tungsten oxide is 0.4 wt% of the mass of the matrix material.

[0056] Comparative Example 8 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (3), the addition of titanium oxide is omitted, and the amount of tungsten element added in tungsten oxide is 0.3 wt% of the mass of the matrix material.

[0057] Comparative Example 9 This comparative example provides a method for preparing a composite-coated ternary cathode material, which is basically the same as the steps in Example 1. The only difference is that in step (3), the addition of zirconium oxide is omitted, and the amount of tungsten element added in tungsten oxide is 0.6 wt% of the mass of the matrix material.

[0058] Experimental Example 1 Scanning electron microscopy (SEM) was performed on the composite-coated ternary cathode materials prepared in Examples 1-4. The results are shown in the figure. Figures 1-4 As shown. From Figures 1-4 As can be seen, the sample is a single-crystal material with a distinct coating layer on its surface.

[0059] Example 2 The cathode materials prepared in Examples 1-4 and Comparative Examples 1-9 were used as the main materials to assemble lithium-ion batteries, and their electrochemical performance was tested. The results are shown in Table 1. The specific steps were as follows: Cathode material: PVDF (polyvinylidene fluoride): super-P (SP) were mixed at a mass ratio of 97.2:1.3:1.5 to prepare cathode slurries. Then, aluminum foil was laid flat on a coating machine for coating, and the coating density was 16 cm³. 2 / mg, dried in a forced-air oven at 80℃ for 2 hours, then punched, weighed, and the electrode baked to make CR2032 button cells; then placed in the Blue Electric test system with a charging voltage of 3.0V-4.5V, a charge-discharge rate of 25% at 1C, 1C discharge, 100 cycles, and thermal stability test at 45℃ for button cell cycle test.

[0060] Table 1. Performance test results of button batteries prepared from the cathode materials of each embodiment and comparative example.

[0061] As can be seen from Table 1, the capacity retention of the button batteries prepared with the cathode materials prepared in Examples 1-4 is in the range of 93.2%-95.3%, which is higher than that of the comparative examples (87.8-92.1%). The capacity retention at 45℃ is in the range of 90.4%-93.1%, which is also higher than that of the comparative examples (85.7%-90.1%).

[0062] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A composite-coated ternary cathode material, comprising a matrix material and a coating layer covering the outer surface of the matrix material, characterized in that, The coating layer includes a first coating layer and a second coating layer, wherein the first coating layer covers at least a portion of the surface of the base material, and the second coating layer covers at least a portion of the surface of the first coating layer; The matrix material includes antimony. The first coating layer contains cobalt and lithium; the second coating layer contains tungsten, aluminum, titanium and zirconium.

2. The composite-coated ternary cathode material according to claim 1, characterized in that, Based on the mass of the matrix material, the cobalt content in the first coating layer is 0.1%-1.6%; And / or, based on the mass of the matrix material, the lithium content in the first coating layer is 0.1%-1.6%.

3. The composite-coated ternary cathode material according to claim 1, characterized in that, Based on the mass of the matrix material, the tungsten content in the second coating layer is 0.1%-0.6%; And / or, based on the mass of the substrate material, the aluminum content in the second coating layer is 0.1%-0.6%; And / or, based on the mass of the matrix material, the titanium content in the second coating layer is 0.1%-0.6%; And / or, based on the mass of the matrix material, the zirconium content in the second coating layer is 0.1%-0.6%.

4. The composite-coated ternary cathode material according to claim 1, characterized in that, The chemical formula of the matrix material is Li f (Ni a Co b Mn c Sb d M e O2, where 0.58≤a≤0.8, 0.1≤b≤0.2, 0.0003≤d≤0.007, 0.0002≤e≤0.009, a+b+c+d+e=1, 1.02≤f≤1.08, and M is at least one of zirconium, yttrium, tungsten, and niobium.

5. A method for preparing a composite-coated ternary cathode material according to any one of claims 1-4, characterized in that, Includes the following steps: (1) The nickel-cobalt-manganese precursor, the first lithium source, and the antimony source are mixed and then subjected to the first sintering to obtain the matrix material; (2) The matrix material, cobalt source and second lithium source are mixed and then subjected to a second sintering to obtain a cobalt-lithium coated matrix material; (3) The cobalt-lithium coated matrix material, tungsten source, aluminum source, titanium source and zirconium source are mixed and then subjected to a third sintering to prepare a composite coated ternary cathode material.

6. The method for preparing the composite-coated ternary cathode material according to claim 5, characterized in that, Step (1) also includes adding a dopant, wherein the dopant includes at least one of the oxides of zirconium, yttrium, tungsten, and niobium; Optionally, the total molar number of metal elements in the matrix material to the molar ratio of metal elements in the dopant is 1:0.0002-0.009; And / or, the total molar number of metal elements in the matrix material to the molar ratio of antimony elements in the antimony source is 1:0.0003-0.007; And / or, the total molar ratio of metal elements in the matrix material to the molar ratio of lithium elements in the first lithium source is 1:1.02-1.08; And / or, the mass of cobalt in the cobalt source accounts for 0.1%-1.6% of the mass of the matrix material; And / or, the mass of lithium in the second lithium source accounts for 0.1%-1.6% of the mass of the matrix material; And / or, the mass of tungsten in the tungsten source accounts for 0.1%-0.6% of the mass of the matrix material; And / or, the mass of aluminum in the aluminum source accounts for 0.1%-0.6% of the mass of the matrix material; And / or, the mass of titanium in the titanium source accounts for 0.1%-0.6% of the mass of the matrix material; And / or, the mass of zirconium element in the zirconium source accounts for 0.1%-0.6% of the mass of the matrix material.

7. The method for preparing the composite-coated ternary cathode material according to claim 5 or 6, characterized in that, The chemical formula of the nickel-cobalt-manganese precursor is Ni x Co y Mn z (OH)2, 0.6≤x≤0.8, 0.1≤y≤0.2, x+y+z=1.

8. The method for preparing the composite-coated ternary cathode material according to claim 5 or 6, characterized in that, The first lithium source includes at least one of lithium hydroxide and lithium carbonate; And / or, the antimony source includes antimony oxide; And / or, the cobalt source includes at least one of cobalt hydroxide, cobalt hydroxyl oxide, and cobalt tetroxide; And / or, the second lithium source includes lithium hydroxide; And / or, the tungsten source includes at least one of tungsten oxide, tungstic acid, and ammonium paratungstate; And / or, the aluminum source includes at least one of aluminum oxide and aluminum hydroxide; And / or, the titanium source includes at least one of titanium oxide and titanium hydroxide; And / or, the zirconium source includes at least one of zirconium oxide, zirconium hydride, and zirconium iodide.

9. The method for preparing the composite-coated ternary cathode material according to claim 5, characterized in that, The first sintering temperature is 700℃-1000℃, the time is 8h-15h, the heating rate is 1℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air. And / or, the second sintering temperature is 600℃-900℃, the time is 3h-7h, the heating rate is 1.5℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air; And / or, the third sintering temperature is 300℃-500℃, the time is 3h-7h, the heating rate is 1.5℃ / min-5℃ / min, and the sintering atmosphere is oxygen or air.

10. The composite-coated ternary cathode material according to any one of claims 1-4 and the composite-coated ternary cathode material prepared by the preparation method according to any one of claims 5-9, and its application in lithium-ion batteries.

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