A synergistically modified high-voltage positive electrode material and a preparation method and application thereof

Abstract

The application relates to the technical field of battery positive electrode materials, in particular to a synergistically modified high-voltage positive electrode material and a preparation method and application thereof, which comprises a bulk particle, a doped layer coated on the surface of the bulk particle and a coating layer coated on the surface of the doped layer; the bulk particle comprises lithium nickel cobalt manganese oxide; the doped layer is lithium nickel cobalt manganese oxide doped with fluorine elements in a bulk phase; and the coating layer comprises a lithium fluoride coating layer and lithium nickel cobalt manganese titanium oxide particles embedded in the lithium fluoride coating layer. The preparation method comprises the following steps: firstly, a nickel cobalt manganese hydroxide precursor is prepared by adopting a coprecipitation method; then, a doped layer and a coating layer are synthesized on the surface of the nickel cobalt manganese hydroxide precursor by adopting a solvothermal method; finally, calcination treatment is carried out to obtain the synergistically modified high-voltage positive electrode material. The synergistic modification strategy of bulk phase doping and surface coating effectively guarantees the stability of the interface and bulk structure, the preparation process is simple, and the electrochemical performance of the positive electrode material under high voltage, high cycle, high rate or high-temperature environment is improved.

Description

Technical Field

[0001] This invention relates to the field of battery cathode material technology, specifically to a synergistically modified high-voltage cathode material, its preparation method, and its application. Background Technology

[0002] With the rapid development of the new energy vehicle and energy storage technology industries, higher requirements have been placed on the energy density, cycle stability, and price of lithium-ion batteries. As the most critical material in lithium-ion batteries, the cathode material determines the battery's performance and cost. Lithium nickel cobalt manganese oxide (LiNiO2) combines the advantages of three layered LiMO2 (M=Ni, Co, Mn) materials (high specific capacity, low cost, and high safety performance, etc.). x Co y Mn 1-x-y O2 (NCM) is one of the most commercially viable cathode materials currently available, possessing significant research potential. The energy density of batteries using NCM ternary cathode materials can be maximized by increasing the cutoff voltage to approach the theoretical capacity limit. However, in practical production applications and scientific research, there are currently many problems, such as frequent and severe side reactions, oxygen loss, and structural degradation, which directly affect the material's cycle performance and high-temperature performance.

[0003] In high-voltage applications (especially above 4.4V), with increasing cycle count, secondary ions or agglomerated single crystals may experience primary particle interface pulverization or separation of agglomerated single crystals in the later stages, leading to increased internal resistance, rapid capacity decay, and a tendency for rapid capacity reduction during high-temperature cycling. These problems severely hinder the commercialization and large-scale application of NCM ternary cathode materials. To improve their performance, current research focuses on bulk doping and surface coating strategies for modification. Bulk doping can stabilize the material structure at the microscopic level, improve electrochemical performance, and is relatively easy to implement with significant improvement effects. Surface coating can prevent direct contact between the cathode material and the electrolyte, thus preventing side reactions and improving the electrochemical performance of the cathode material, such as dispersibility, stability, and discharge rate.

[0004] CN112447951A discloses a positive electrode active material, its preparation method, a positive electrode sheet, and a lithium-ion secondary battery. The positive electrode active material includes bulk particles and a coating layer covering the outer surface of the bulk particles. The bulk particles include lithium nickel cobalt manganese oxide, and the coating layer includes an oxide of element M1. The bulk particles are doped with elements M2 and M3, with the M2 element uniformly distributed and the M3 element exhibiting a decreasing concentration gradient from the outer surface to the core of the bulk particles. Elements M1 and M3 are each independently selected from one or more of Mg, Al, Ca, Ba, Ti, Zr, Zn, and B. Element M2 includes one or more of Si, Ti, Cr, Mo, V, Ge, Se, Zr, Nb, Ru, Rh, Pd, Sb, Te, Ce, and W. Using this positive electrode active material enables lithium-ion secondary batteries to possess high energy density, high-temperature cycle performance, and high-temperature storage performance. This represents a valuable attempt in the field. Summary of the Invention

[0005] The purpose of this invention is to provide a synergistically modified high-voltage cathode material, its preparation method, and its application. It uses a synergistic modification strategy of bulk doping and surface coating to effectively ensure the stability of the interface and bulk structure. While simplifying the preparation process, it also improves the electrochemical performance of the cathode material under high voltage, high cycle, high rate, or high and low temperature environments.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] In a first aspect, the present invention provides a synergistically modified high-voltage cathode material, comprising bulk particles, a doped layer coated on the surface of the bulk particles, and a coating layer coated on the surface of the doped layer; the bulk particles comprise lithium nickel cobalt manganese oxide; the doped layer is lithium nickel cobalt manganese oxide bulk doped with fluorine, wherein the fluorine concentration gradient in the doped layer decreases from the outer surface to the core; the coating layer comprises a lithium fluoride coating and lithium nickel cobalt manganese titanate particles embedded in the lithium fluoride coating.

[0008] Furthermore, the general chemical formula of the lithium nickel cobalt manganese titanate particles in the coating layer is Li. a Ni x Co y Mn 1-x-y-b Ti b O2, of which, 1 <a<1.3,0<b<0.1,0.7<x<1,0<y<0.1。

[0009] Furthermore, F element is gradient doped, that is, F is doped from the core outwards along the growth direction. + The concentration was increased from 0.10% (atomic fraction) to 2% (atomic fraction).

[0010] Furthermore, the coating thickness is 10~30nm.

[0011] Secondly, the present invention provides a method for preparing a synergistically modified high-voltage cathode material. The method first uses a co-precipitation method to prepare a nickel-cobalt-manganese hydroxide precursor, then uses a solvothermal method to synthesize a doped layer and a coating layer on the surface of the nickel-cobalt-manganese hydroxide precursor, and finally performs calcination treatment to obtain the above-mentioned synergistically modified high-voltage cathode material.

[0012] Furthermore, the preparation of the nickel-cobalt-manganese hydroxide precursor by co-precipitation method is as follows: nickel, cobalt, and manganese sulfates are weighed according to stoichiometric ratio, sodium hydroxide is used as a precipitant, ammonia is used as a complexing agent, the pH of the reaction solution is adjusted to 11±0.5, and a nickel-cobalt-manganese hydroxide precursor solution is prepared under a stirring speed of 340~380 rpm; the synthesis of doped and coated layers on the surface of the nickel-cobalt-manganese hydroxide precursor by solvothermal method is as follows: lithium salt, titanium salt, and ammonium fluoride are added to the nickel-cobalt-manganese hydroxide precursor solution, and precursor powder is obtained through solvothermal reaction.

[0013] Furthermore, the concentration of sodium hydroxide in the reaction solution is not less than 2 mol / L, and the concentration of ammonia in the reaction solution is 7~9 g / L;

[0014] Furthermore, the molar ratio of the nickel cobalt manganese hydroxide precursor, lithium salt, titanium salt, and ammonium fluoride is 1:0.5~0.8:0.05~0.1:0.1~0.15.

[0015] Furthermore, the lithium salt is selected from one or more of lithium carbonate, lithium hydroxide, lithium nitrate, and lithium acetate; the titanium salt is selected from one or more of titanium butoxide and alkyl titanate.

[0016] Furthermore, the calcination treatment specifically involves calcining under an argon atmosphere, with the calcination temperature set at 700~800℃ and the calcination time set at 7~10h.

[0017] Thirdly, the present invention provides the application of the above-mentioned synergistically modified high-voltage cathode material or the synergistically modified high-voltage cathode material prepared by the above-mentioned method in batteries.

[0018] The beneficial effects of this invention are:

[0019] 1. The bulk particles of the present invention are coated with a doped layer, and the doped layer is a bulk lithium nickel cobalt manganese oxide doped with fluorine. The fluorine concentration gradient in the doped layer decreases from the outer surface to the core. The improvement in battery cycle stability due to bulk fluorine doping is mainly because after fluorine enters the lithium nickel cobalt manganese oxide ternary material lattice, it reduces the Li₂ concentration during the charging and discharging process of the cathode material. + / Ni 2+ The degree of mixing can effectively avoid Li + The collective collapse of the layers stabilizes the layered structure, providing lattice positions for lithium ion extraction and insertion, thereby improving the cell's cycle performance.

[0020] 2. The doped layer of the present invention is coated with a coating layer, which includes a lithium fluoride coating and lithium nickel cobalt manganese titanate particles embedded in the lithium fluoride coating. This coating layer exhibits stable electrochemical performance, acts as a physical barrier for the bulk particles, effectively reduces the amount of lithium residue on the surface of the cathode material, inhibits direct contact between the cathode material and the electrolyte, reduces the dissolution of transition metal ions and the formation of cracks in the electrode material, lowers the charge transfer resistance during cycling, and improves the Li... + This improves diffusion efficiency and enhances various electrochemical properties of the cathode material, such as high discharge capacity and cycle stability.

[0021] 3. This invention utilizes bulk particles, namely LiNi x Co y Mn 1-x-y A nanostructure from the outside in was fabricated on O2 crystals. The electrochemically stable lithium fluoride coating and the nickel-cobalt-manganese titanate particles embedded within it act as a physical barrier, preventing direct contact between the NCM ternary cathode material and the electrolyte, thus avoiding side reactions. The internal fluorine doping stabilizes the lattice oxygen and promotes Li... + The diffusion of these molecules, through the spinel-like transition doped layers between them, forms a robust and complete lithium-ion transport channel along the lithium concentration gradient. This ensures rate performance while improving battery energy density and cycle life, making it suitable for charge-discharge cycles at higher cutoff voltages. Attached Figure Description

[0022] 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 embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0023] Figure 1 This is a cross-sectional schematic diagram of the synergistically modified high-voltage cathode material described in this invention. In the figure, 1—bulk particles, 2—doped layer, and 3—coating layer.

[0024] Figure 2 This diagram illustrates the rate cycling test results of lithium-ion batteries prepared based on the synergistically modified high-voltage cathode material of Embodiment 1 of the present invention and the comparative ternary cathode material. The horizontal axis represents the cycle number, and the vertical axis represents the capacity, with units of mAh·g. -1 . Detailed Embodiments

[0025] The following will illustrate the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the protection scope of the present invention.

[0026] It should be noted that the diagrams provided in the following embodiments only schematically illustrate the basic concept of the present invention. The diagrams only show the components related to the present invention and are not drawn according to the number, shape, and size of the components in actual implementation. The type, quantity, and ratio of each component in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0027] Example 1, A preparation method of a co-modified high-voltage cathode material, comprising the following steps:

[0028] S1, Prepare a nickel-cobalt-manganese hydroxide precursor by the coprecipitation method. Specifically: Weigh nickel, cobalt, and manganese sulfates according to the stoichiometric ratio and add them to a reaction kettle for mixing and dissolution. Prepare a salt solution with a mixed ion concentration of about 3 mol / L, then add 0.5 mol / L (i.e., 8.5 g / L) of ammonia water for complexation, add a 4 mol / L sodium hydroxide solution and stir until the pH value of the solution is 11, and continuously introduce nitrogen into the reaction kettle. Adjust the temperature to be stable at 65 °C, and complete the coprecipitation reaction under the conditions of a stirring speed of 360 rpm and a stirring time of 18 h to obtain a nickel-cobalt-manganese hydroxide precursor solution. The chemical general formula of this nickel-cobalt-manganese hydroxide is Ni x Co y Mn 1-x-y (OH)2, where, 0.7 < x < 1, 0 < y < 0.1. In this example, x = 0.75, y = 0.05.

[0029] S2, Synthesize a doping layer and a coating layer on the surface of the nickel-cobalt-manganese hydroxide precursor by the solvothermal method. Specifically, add the prepared nickel-cobalt-manganese hydroxide, lithium carbonate, titanium butoxide, and ammonium fluoride to the reaction kettle according to a molar ratio of 1:0.8:0.1:0.15, set the stirring speed to 360 rpm, and obtain a precursor powder through the solvothermal reaction. It should be noted that during the solvothermal synthesis process, titanium elements tend to be in the surface coating layer, and fluorine elements diffuse into the bulk in a gradient manner, forming a spinel-like transition layer connected by titanium and fluorine doping. Therefore, during the preparation, an excessive amount of ammonium fluoride needs to be added to ensure continuous fluorine incorporation into the bulk, and the surplus fluoride ions on the surface can be rinsed with ethanol.

[0030] S3. The precursor powder obtained in S2 was calcined at a temperature of 750℃ for 8 hours to obtain a synergistically modified high-voltage cathode material with an OIN-NCM structure.

[0031] See Figure 1 As shown, the synthesized synergistically modified high-voltage cathode material includes bulk particles 1, a doped layer 2 coating the surface of the bulk particles 1, and a coating layer 3 coating the surface of the doped layer 2. The bulk particles 1 comprise lithium nickel cobalt manganese oxide. The doped layer 2 is a bulk-doped lithium nickel cobalt manganese oxide with fluorine, and the fluorine concentration gradient in the doped layer decreases from the outer surface to the core. The coating layer 3 comprises a lithium fluoride coating and lithium nickel cobalt manganese titanate particles embedded in the lithium fluoride coating. The highest Fo of the doped layer 2 is... + The concentration is 2% (atomic fraction), and the thickness of the coating layer 3 is 30 nm.

[0032] The general chemical formula of the lithium nickel cobalt manganese titanate particles in the coating layer is Li a Ni x Co y Mn 1-x-y-b Ti b O2, in this embodiment, a=1.25, b=0.075, x=0.75, y=0.05.

[0033] In Comparative Example 1, the nickel-cobalt-manganese hydroxide precursor solution prepared in S1 of Example 1 and lithium carbonate were weighed at a molar ratio of 1:0.8 and added to the reaction vessel. The rest of the steps were the same as in Example 1, and an uncoated and undoped ternary cathode material was obtained.

[0034] Lithium-ion coin cells were fabricated using the synergistically modified high-voltage cathode material obtained in Example 1 and the uncoated and undoped ternary cathode materials obtained in Comparative Example 1, respectively. Rate cycling tests were then conducted, with 5 cycles each at discharge conditions of 0.1C, 0.2C, 0.33C, 0.5C, 1C, and 0.1C, and the voltage range was set to 3.0~4.45V. The test results are shown below. Figure 2 ,

[0035] Depend on Figure 2It can be seen that, compared with the comparative example, the co-modified high-voltage cathode material with the OIN-NCM structure of the present invention has significantly improved results in the rate cycle test of the battery under high-voltage conditions. The reason is that the surface of the body particles in the embodiment of the present invention is coated with a doped layer, and the doped layer is lithium nickel cobalt manganese oxide doped with fluorine in the bulk phase. The fluorine element in the doped layer has a decreasing concentration gradient from the outer surface to the core direction of the doped layer. The improvement effect of the bulk doping of fluorine element on the battery cycle stability is mainly because after the fluorine element enters the lattice of the lithium nickel cobalt manganese ternary material, during the charge and discharge process of the cathode material, it reduces the Li + / Ni 2+ mixing degree, and can effectively avoid the collective collapse of the Li + layer, thereby stabilizing the layered structure, providing lattice position guarantee for the extraction and insertion of lithium ions, and thus improving the cycle performance of the battery cell. The surface of the doped layer is coated with a coating layer, and the coating layer includes a lithium fluoride coating and lithium nickel cobalt manganese titanate particles embedded in the lithium fluoride coating. The coating layer has stable electrochemical performance and plays a physical barrier role on the body particles, effectively reducing the lithium residue amount on the surface of the cathode material, inhibiting the direct contact between the cathode material and the electrolyte, reducing the dissolution of transition metal ions and the formation of cracks in the electrode material, reducing the charge transfer resistance during the cycle process, and improving the Li + diffusion efficiency, while improving various electrochemical performances such as the high discharge capacity and cycle stability of the cathode material.

[0036] Example 2, a preparation method of a co-modified high-voltage cathode material, includes the following steps:

[0037] S1, obtaining a nickel cobalt manganese hydroxide precursor by a co-precipitation method. Specifically: Weigh nickel, cobalt, and manganese sulfates according to the stoichiometric ratio and add them to a reaction kettle for mixing and dissolution. Prepare a salt solution with a mixed ion concentration of about 3 mol / L, then add 7 g / L of ammonia water for complexation, add a 4 mol / L sodium hydroxide solution and stir until the pH value of the solution is 10.5, and continuously introduce nitrogen into the reaction kettle. Adjust the temperature to be stable at 65 °C, and complete the co-precipitation reaction under the conditions of a stirring speed of 340 rpm and a stirring time of 18 h to obtain a nickel cobalt manganese hydroxide precursor solution. The chemical general formula of this nickel cobalt manganese hydroxide is Ni x Co y Mn 1-x-y (OH)2, where 0.7 < x < 1 and 0 < y < 0.1. In this example, x = 0.75 and y = 0.05.

[0038] S2. Synthesize a doping layer and a coating layer on the surface of the nickel-cobalt-manganese hydroxide precursor by the solvothermal method. Specifically, add the prepared nickel-cobalt-manganese hydroxide, lithium carbonate, alkyl titanate, and ammonium fluoride into the reaction kettle according to the molar ratio of 1:0.5:0.05:0.1, set the stirring speed to 340 rpm, and obtain the precursor powder through the solvothermal reaction.

[0039] S3. Calcinate the precursor powder obtained in S2. Set the calcination temperature to 700 °C and the calcination time to 10 h to obtain a synergistically modified high-voltage cathode material with an OIN-NCM structure. Through electrochemical testing, the lithium-ion button battery based on the prepared synergistically modified high-voltage cathode material has good cycle rate performance under high-voltage conditions.

[0040] Example 3. A preparation method of a synergistically modified high-voltage cathode material, comprising the following steps:

[0041] S1. Prepare a nickel-cobalt-manganese hydroxide precursor by the co-precipitation method. Specifically, weigh nickel, cobalt, and manganese sulfates according to the stoichiometric ratio, add them into the reaction kettle for mixing and dissolution, prepare a salt solution with a mixed ion concentration of about 3 mol / L, then add 9 g / L of ammonia water for complexation, add a 3 mol / L sodium hydroxide solution and stir until the pH value of the solution is 11.5, continuously introduce nitrogen into the reaction kettle, adjust the temperature to be stable at 65 °C, and complete the co-precipitation reaction under the conditions of a stirring speed of 360 rpm and a stirring time of 16 h to obtain a nickel-cobalt-manganese hydroxide precursor solution. The chemical general formula of this nickel-cobalt-manganese hydroxide is Ni x Co y Mn 1-x-y (OH)2, where 0.7 < x < 1 and 0 < y < 0.1. In this example, x = 0.75 and y = 0.05.

[0042] S2. Synthesize a doping layer and a coating layer on the surface of the nickel-cobalt-manganese hydroxide precursor by the solvothermal method. Specifically, add the prepared nickel-cobalt-manganese hydroxide, lithium carbonate, alkyl titanate, and ammonium fluoride into the reaction kettle according to the molar ratio of 1:0.8:0.1:0.15, set the stirring speed to 340 rpm, and obtain the precursor powder through the solvothermal reaction.

[0043] S3. Calcinate the precursor powder obtained in S2. Set the calcination temperature to 800 °C and the calcination time to 7 h to obtain a synergistically modified high-voltage cathode material with an OIN-NCM structure. Through electrochemical testing, the lithium-ion button battery based on the prepared synergistically modified high-voltage cathode material has good cycle rate performance under high-voltage conditions.

[0044] Example 4. A preparation method of a synergistically modified high-voltage cathode material, comprising the following steps:

[0045] S1. The nickel-cobalt-manganese hydroxide precursor is prepared by the co-precipitation method. Specifically, sulfates of nickel, cobalt, and manganese are weighed according to the stoichiometric ratio and added to a reaction kettle for mixing and dissolution to prepare a salt solution with a mixed ion concentration of about 3 mol / L. Then, 7.5 g / L of ammonia water is added for complexation, and a 4 mol / L sodium hydroxide solution is added and stirred until the pH value of the solution reaches 11.5. Nitrogen is continuously introduced into the reaction kettle, and the temperature is adjusted to be stable at 65 °C. The co-precipitation reaction is completed under the conditions of a stirring speed of 380 rpm and a stirring time of 20 h to obtain a nickel-cobalt-manganese hydroxide precursor solution. The chemical general formula of this nickel-cobalt-manganese hydroxide is Ni x Co y Mn 1-x-y (OH)2, where 0.7 < x < 1 and 0 < y < 0.1. In this embodiment, x = 0.75 and y = 0.05.

[0046] S2. The doping layer and the coating layer are synthesized on the surface of the nickel-cobalt-manganese hydroxide precursor by the solvothermal method. Specifically, the prepared nickel-cobalt-manganese hydroxide, lithium carbonate, alkyl titanate, and ammonium fluoride are added to the reaction kettle according to the molar ratio of 1:0.7:0.08:0.12, and the stirring speed is set to 360 rpm. Through the solvothermal reaction, the precursor powder is obtained.

[0047] S3. The precursor powder obtained in S2 is subjected to a calcination treatment. The calcination treatment temperature is set to 800 °C, and the calcination treatment time is set to 8 h to obtain a synergistically modified high-voltage cathode material with an OIN-NCM structure. Through electrochemical tests, the lithium-ion button battery based on the prepared synergistically modified high-voltage cathode material has good cycle rate performance under high-voltage conditions.

[0048] The above embodiments are only preferred embodiments cited to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims

1. A method for preparing a synergistically modified high-voltage cathode material, characterized in that: First, a nickel cobalt manganese hydroxide precursor was prepared by co-precipitation. Then, a doped layer and a coating layer were synthesized on the surface of the nickel cobalt manganese hydroxide precursor by solvothermal method. Specifically, lithium salt, titanium salt and ammonium fluoride were added to the nickel cobalt manganese hydroxide precursor solution, and the precursor powder was obtained through solvothermal reaction. Finally, the precursor powder was calcined to obtain a synergistically modified high voltage cathode material. The synergistically modified high-voltage cathode material includes bulk particles, a doped layer coated on the surface of the bulk particles, and a coating layer coated on the surface of the doped layer. The bulk particles include lithium nickel cobalt manganese oxide; The doped layer is a bulk lithium nickel cobalt manganese oxide doped with fluorine, and the concentration gradient of fluorine in the doped layer decreases from the outer surface to the core. The coating layer includes a lithium fluoride coating and lithium nickel cobalt manganese titanate particles embedded in the lithium fluoride coating.

2. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that: The general chemical formula of the lithium nickel cobalt manganese titanate particles in the coating layer is Li a Ni x Co y Mn 1-x-y-b Ti b O2, of which, 1 <a<1.3,0<b<0.1,0.7<x<1,0<y<0.1。 3. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that: The coating thickness is 10~30nm.

4. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that, The nickel-cobalt-manganese hydroxide precursor was prepared by co-precipitation as follows: nickel, cobalt, and manganese sulfates were weighed according to the stoichiometric ratio, sodium hydroxide was used as a precipitant, ammonia was used as a complexing agent, the pH of the reaction solution was adjusted to 11±0.5, and the nickel-cobalt-manganese hydroxide precursor solution was prepared under the condition of stirring speed of 340~380 rpm.

5. The method for preparing the synergistically modified high-voltage cathode material according to claim 4, characterized in that: The concentration of sodium hydroxide in the reaction solution is not less than 2 mol / L, and the concentration of ammonia in the reaction solution is 7~9 g / L.

6. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that: The molar ratio of the nickel-cobalt-manganese hydroxide precursor, lithium salt, titanium salt, and ammonium fluoride is 1:0.5~0.8:0.05~0.1:0.1~0.

15.

7. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that: The lithium salt is selected from one or more of lithium carbonate, lithium hydroxide, lithium nitrate, and lithium acetate; The titanium salt is selected from one or more of butanol titanium salt and alkyl titanate.

8. The method for preparing the synergistically modified high-voltage cathode material according to claim 1, characterized in that, The calcination process is specifically carried out under an argon atmosphere, with the calcination temperature set at 700~800℃ and the calcination time set at 7~10h.

9. The application of the synergistically modified high-voltage cathode material prepared by the preparation method of the synergistically modified high-voltage cathode material according to any one of claims 1 to 8 in a battery.

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