Method for preparing heavily coated cobalt oxide and its use

Abstract

The present invention discloses a method for preparing and using a heavily coated cobalt oxide. First, spherical cobalt hydroxide particles are synthesized by a co-precipitation method. Then, the spherical cobalt hydroxide particles are dried, dehydrated, and uniformly mixed with zirconium alkyl carboxylate / aluminum alkyl carboxylate and zirconium hydroxide / aluminum hydroxide. The mixture is then heated to react with the cobalt hydroxide on the particle surface, causing it to adhere closely to the surface of the spherical cobalt hydroxide particles. Finally, the particles are calcined to remove organic matter, resulting in spherical cobalt oxide particles with a strong coating on their surface.In the present invention, the coating layer and the base material are connected through chemical bonds, which makes the two adhere to each other more closely, so that the coating layer is not easy to spray off and peel off, greatly extending the service life of the coating layer, and improving the cycle performance of the material.

Description

Method for preparing heavily coated cobalt oxide and its use Field This disclosure relates to the field of precursors of positive electrode material for lithium-ion batteries, and in particular to a method for preparing a heavily coated cobalt oxide and its use. Background Lithium cobalt oxide electrode material has high specific capacity and good cycle stability, making it a widely used positive electrode material in the 3C field. With the rapid development of 3C electronics, manufacturers continue to place higher demands on the processing performance and electrochemical properties of lithium cobalt oxide positive electrode materials. As the first commercially available positive electrode material for lithium-ion batteries, lithium cobalt oxide remains one of the most compact positive electrode materials in practical applications. Lithium cobalt oxide has a typical layered structure, in which cobalt ions and lithium ions alternately occupy the gaps in the closed layers formed by oxygen ions.According to the amount of lithium ions that can be extracted from lithium cobalt oxide, the theoretical mass specific capacity of lithium cobalt oxide is approximately 274 mAh / g. With the rapid development of fields such as smart electronic devices, there is an urgent need for high-energy-density lithium batteries with long lifespans and high safety. The use of positive electrodes with high voltage and high specific capacity is an effective way to improve battery energy density. Lithium cobalt oxide (LCO) positive electrode material has received extensive attention due to its high theoretical specific capacity, but many problems and challenges remain in its use at high voltages, especially issues such as structural phase changes at the electrolyte interface, dissolution of transition metals, oxygen precipitation, and continuous oxidative decomposition of the electrolyte. These severely limit the use of LCO positive electrode material in high-energy-density lithium batteries. In light of the aforementioned problems, in the prior art, the structural and electrochemical properties of the particles can be optimized by forming a coating layer on the material's surface. This improves the material's corrosion resistance and reduces secondary reactions between the material and the electrolyte. By applying a thin, stable coating layer to the material's surface—common coating materials being oxides, fluorides, lithium-ion conductors, and the like—the coating layer can reduce the contact resistance between the particles and simultaneously separate the material from the electrolyte. This minimizes secondary reactions between the material and the electrolyte and prevents corrosion of the positive electrode material by HF gas generated from electrolyte decomposition. Patent document CN103359795A discloses a precursor for a multi-element lithium-ion battery positive electrode material coated with cobalt oxide and a method for preparing it. The method employs a "wet coating + sintering" process to obtain a high-quality, compact cobalt oxide coating layer on the sphere's surface. However, the coating layer is prone to pulverizing and peeling during long-term cycling, re-exposing the lithium cobalt oxide to the corroding electrolyte and negatively impacting the material's cycling performance. Brief description of the invention The present invention aims to solve at least one of the technical problems existing in the aforementioned prior art. Therefore, the present invention provides a method for preparing and using a heavily coated cobalt oxide. This method can obtain a heavily coated cobalt oxide layer, greatly extending the service life of the coating layer and further improving the material's cycle performance. In one aspect, the present invention provides a method for preparing a heavily coated cobalt oxide, comprising the following steps: S1: Add a cobalt salt solution, a sodium hydroxide solution, and aqueous ammonia in parallel to a base solution to react, until the reaction material reaches the target particle size, perform aging of the mixture, then subject the resulting mixture to solid-liquid separation to obtain a precipitate, and wash and dry the precipitate to obtain a dry material; S2: Add the dry material and the hydroxide to an organic metal carboxylate solution, heat the mixture to evaporate the solvent, and when the rate of evaporation of the solvent reaches more than 90%, heat the mixture to 180-200 °C to react; wherein the hydroxide is zirconium hydroxide or aluminum hydroxide, and the organic metal carboxylate solution is an alcohol solution of zirconium alkylcarboxylate or aluminum alkylcarboxylate; S3: calcine the product after the reaction of step S2 in an oxygen atmosphere to obtain cobalt oxide. In some embodiments of the present invention, in step S1, the concentration of the cobalt salt solution is 1.0-2.0 moles / L, and the concentration of the sodium hydroxide solution is 4.0-10.0 moles / L. In some embodiments of the present invention, in step S1, the concentration of the aqueous ammonia added in parallel is 6.0-12.0 moles / L. In some embodiments of the present invention, in step S1, the base solution is a mixed solution of sodium hydroxide and aqueous ammonia, the pH of the base solution is 10 11, and the ammonia concentration is 5.0-10.0 g / L. In some embodiments of the present invention, in step S1, the reaction temperature is controlled to be 55-65 °C, the pH of the reaction material is controlled to be 10-11, and the ammonia concentration is controlled to be 5-10 g / L. In some embodiments of the present invention, in step S1, the target particle size of the reaction material is 2.0 pm-15.0 pm. In some embodiments of the present invention, in step S1, the aging duration is 1-2 h. In some embodiments of the present invention, in step S1, the drying temperature is 100-120 °C, and the drying time is 4-6 h. In some embodiments of the present invention, in step S2, the ratio between the weight of the dry material and the volume of the organic metal carboxylate solution (solid-liquid ratio) is 1 g: (1-5) ml, and the concentration of the metal carboxylate in the organic metal carboxylate solution is 0.1-0.2 moles / L. In some embodiments of the present invention, in step S2, the amount of hydroxide added is 1-5% of the weighted amount of dry material. In some embodiments of the present invention, in step S2, the heating temperature for evaporating the solvent is 70-80 °C. In some embodiments of the present invention, in step S2, the reaction time is 15-30 min. In some embodiments of the present invention, in step S2, the number of carbon atoms in the alkyl segment in the zirconium alkylcarboxylate or aluminum alkylcarboxylate is 6-10. In some embodiments of the present invention, in step S3, the calcination temperature is 500-750 °C. In some embodiments of the present invention, in step S3, the duration of calcination is 2-6 h. The present invention also provides for the application of the method in the preparation of lithium cobalt oxide or lithium ion batteries. According to a preferred embodiment of the present invention, it has at least the following beneficial effects: 1 1. In the present invention, spherical cobalt hydroxide particles are first synthesized by a co-precipitation method. These spherical cobalt hydroxide particles are then dried, dehydrated, and uniformly mixed with zirconium alkylcarboxylate / aluminum alkylcarboxylate and zirconium hydroxide / aluminum hydroxide. The mixture is then heated to react with the cobalt hydroxide on the particle surface, causing it to adhere closely to the surface of the spherical cobalt hydroxide particles. Finally, the particles are calcined to remove organic matter, forming spherical cobalt oxide particles with a tight coating layer on the surface. The reaction equation is as follows: In the co-precipitation reaction: Co2 + +2OH-^Co (OH) 2 ; Taking zirconium hydroxide and zirconium alkylcarboxylate as an example, in the co-thermal reaction: (RnCOO)4Zr+4Zr (OH) 4^[RnCOO-Zr (OH) 2-O]4-Zr+4H2O; (RnCOO)4Zr+4Co (OH)2^ (RnCOO-Co-O)4-Zr+4H2O; Referring to the previous reaction, in the present invention, a Co-O-Zr-O-Co or Co-O-Al-O-Co bond can be formed during the co-thermal reaction in step S2, such that the subsequent zirconium / aluminum and cobalt are closely linked through an oxide bond. The addition of zirconium hydroxide / aluminum hydroxide can increase the zirconium / aluminum content of the coating layer and reduce the cobalt content. 2. The coating on the surface of the spherical particles is not pure zirconium / alumina, but rather cobalt zirconium oxide or cobalt aluminum oxide, formed by the chemical bonding of the zirconium / aluminum with the cobalt oxide on the particle surface. Compared to traditional coating methods, in the present invention, the coating layer and the base material are connected through chemical bonds, resulting in a closer bond between the two. This makes the coating layer less prone to spraying and shedding, significantly extending its lifespan and improving the material's cycle performance.Subsequently, in the preparation of the lithium cobalt oxide positive electrode material, due to the zirconium / alumina on the surface of the cobalt oxide, the problem of cobalt dissolution in lithium cobalt oxide due to long-term cycling can be prevented, further improving the cycling performance of the material. Brief description of the drawings The present invention will be described later together with drawings and examples, in which: FIGURE 1 is the SEM image of the cobalt oxide prepared in Example 1 of the present invention. Detailed description of the invention The concept of the present invention and the technical effects produced by it will be clearly and completely described below with reference to the examples, in order to fully understand the purpose, features, and effects of the present invention. Obviously, the examples described are only a portion of the embodiments of the present invention, rather than all of them. Based on the examples of the present invention, other examples obtained by those skilled in the art without creative effort are all within the scope of protection of the present invention. Example 1 In this example, a heavily coated cobalt oxide was prepared. The specific process is: Step 1: A cobalt sulfate solution was prepared with a concentration of 2.0 moles / L; Step 2: A sodium hydroxide solution with a concentration of 10.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 12.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 10.5, and the concentration of ammonia was 5.0 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 500 rpm, the pH to 10.5, the temperature to 55 °C, and the ammonia concentration to 5 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 15.0 pm, the feeding was stopped and the material was aged for 2 hours; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the resulting precipitate was washed with pure water and dried at 120 °C for 4 hours to obtain a dry material; Step 8: In accordance with the solid-liquid ratio of 1 g:5 mL, the dry material was added to an ethanol solution of aluminum octoate (CAS No. 6028-57-5) with a concentration of 0.2 mol / L. Then, aluminum hydroxide was added to the mixture at a concentration of 5% of the weight of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate the organic solvent, which was then recovered. When the organic solvent recovery rate reached over 90%, the heating of the mixture was intensified, and when the temperature reached 200 °C, that temperature was maintained for 15 minutes. Step 9: The product obtained in step 8 was calcined at 500 °C in an oxygen atmosphere for 6 hours to obtain a heavily coated cobalt oxide. Example 2 In this example, a heavily coated cobalt oxide was prepared. The specific process is: Step 1: A cobalt nitrate solution was prepared with a concentration of 1.5 moles / L; Step 2: A sodium hydroxide solution with a concentration of 7.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 10.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 10.8, and the concentration of ammonia was 7 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 350 rpm, the pH to 10.8, the temperature to 60 °C, and the ammonia concentration to 7 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 10.0 pm, the feeding was stopped and the material was aged for 1.5 h; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the resulting precipitate was washed with pure water and dried at 110 °C for 5 hours to obtain a dry material; Step 8: In accordance with the solid-liquid ratio of 1 g:3 mL, the dry material was added to a zirconium octoate (CAS: 18312-04-4) ethanol solution with a concentration of 0.15 mol / L. Then, zirconium hydroxide was added at a concentration of 3% of the weight of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate and recover the organic solvent. When the organic solvent recovery rate exceeded 90%, the heating of the mixture was intensified, and when the temperature reached 190 °C, it was maintained at that temperature for 20 minutes. Step 9: The product obtained in step 8 was calcined at 650 °C in an oxygen atmosphere for 4 hours to obtain a heavily coated cobalt oxide. Example 3 In this example, a heavily coated cobalt oxide was prepared. The specific process s: Step 1: A cobalt chloride solution was prepared with a concentration of 1.0 moles / L; Step 2: A sodium hydroxide solution with a concentration of 4.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 6.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 11, and the concentration of ammonia was 10.0 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 200 rpm, the pH to 11, the temperature to 65 °C, and the ammonia concentration to 10 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 5.0 pm, the feeding was stopped and the material was aged for 1 hour; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the resulting precipitate was washed with pure water and dried at 100 °C for 6 hours to obtain a dry material; Step 8: In accordance with the solid-liquid ratio of 1 g:1 mL, the dry material was added to an ethanol solution of zirconium 2-ethylhexanoate (CAS: 2233-42-3) with a concentration of 0.1 mol / L. Then, zirconium hydroxide was added at a concentration of 1% of the weight of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate the organic solvent, which was then recovered. When the organic solvent recovery rate exceeded 90%, the heating of the mixture was intensified, and when the temperature reached 180 °C, it was maintained for 30 minutes. Step 9: The product obtained in step 8 was calcined at 750 °C in an air atmosphere for 2 hours to obtain a heavily coated cobalt oxide. Comparative Example 1 In this example, a cobalt oxide was prepared, which differs from example 1 in that aluminum octoate was not added. The specific process is: Step 1: A cobalt sulfate solution was prepared with a concentration of 2.0 moles / L; Step 2: A sodium hydroxide solution with a concentration of 10.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 12.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 10.5, and the concentration of ammonia was 5.0 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 500 rpm, the pH to 10.5, the temperature to 55 °C, and the ammonia concentration to 5 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 15.0 pm, the feeding was stopped and the material was aged for 2 hours; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the precipitate obtained was washed with pure water and dried at 120°C for 4 hours to obtain a dry material; Step 8: According to the solid-liquid ratio of 1 g:5 mL, the dry material was added to an ethanol solution, then aluminum hydroxide was added at a rate of 12.8% of the weight of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate the organic solvent, which was then recovered. When the organic solvent recovery rate reached over 90%, the heating of the mixture was intensified, and when the temperature reached 200 °C, that temperature was maintained for 15 minutes. Step 9: The product obtained in step 8 was calcined at 500 °C in an oxygen atmosphere for 6 hours to obtain a coated cobalt oxide. Comparative Example 2 In this example, a cobalt oxide was prepared, which differs from example 2 in that zirconium octoate was not added. The specific process is: Step 1: A cobalt nitrate solution was prepared with a concentration of 1.5 moles / L; Step 2: A sodium hydroxide solution with a concentration of 7.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 10.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 10.8, and the concentration of ammonia was 7 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 350 rpm, the pH to 10.8, the temperature to 60 °C, and the ammonia concentration to 7 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 10.0 qm, the feeding was stopped and the material was aged for 1.5 h; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the resulting precipitate was washed with pure water and dried at 110 °C for 5 hours to obtain a dry material; Step 8: According to the solid-liquid ratio of 1 g:3 mL, the dry material was added to an ethanol solution, then zirconium hydroxide was added at a rate of 14.5% of the weight of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate the organic solvent, which was then recovered. When the organic solvent recovery rate reached over 90%, the heating of the mixture was intensified, and when the temperature reached 190 °C, that temperature was maintained for 20 minutes. Step 9: The product obtained in step 8 was calcined at 650 °C in an oxygen atmosphere for 4 hours to obtain a coated cobalt oxide. Comparative Example 3 In this example, a cobalt oxide was prepared, which differs from example 3 in that zirconium 2-ethylhexanoate was not added. The specific process is: Step 1: A cobalt chloride solution was prepared with a concentration of 1.0 moles / L; Step 2: A sodium hydroxide solution with a concentration of 4.0 moles / L was prepared as a precipitating agent; Step 3: Aqueous ammonia with a concentration of 6.0 moles / L was prepared as a complexing agent; Step 4: Pure water was added to a reaction kettle to overflow the lower stirring paddle, then a certain amount of sodium hydroxide solution prepared in step 2 and aqueous ammonia prepared in step 3 were added to the kettle to form a base solution for the initial reaction, wherein the pH value of the base solution was 11, and the concentration of ammonia was 10.0 g / L; Step 5: The cobalt salt solution prepared in step 1, the sodium hydroxide solution prepared in step 2, and the aqueous ammonia prepared in step 3 were added in parallel to the reaction kettle to react. In the reaction kettle, the stirring speed was controlled to 200 rpm, the pH to 11, the temperature to 65 °C, and the ammonia concentration to 10 g / L. Step 6: When the D50 of the material in the reaction kettle was detected to reach 5.0 pm, the feeding was stopped and the material was aged for 1 hour; Step 7: The material in the kettle was subjected to solid-liquid separation, and then the resulting precipitate was washed with pure water and dried at 100 °C for 6 hours to obtain a dry material; Step 8: According to the solid-liquid ratio of 1 g:1 mL, the dry material was added to an ethanol solution, then zirconium hydroxide was added at a rate of 3.5% of the dry material. The resulting mixture was thoroughly mixed and heated (to 70-80 °C) under constant stirring to evaporate the organic solvent, which was then recovered. When the organic solvent recovery rate reached over 90%, the heating of the mixture was intensified, and when the temperature reached 180 °C, that temperature was maintained for 30 minutes. Step 9: The product obtained in step 8 was calcined at 750 °C in an air atmosphere for 2 hours to obtain a heavily coated cobalt oxide. Test example The cobalt oxides obtained in Examples 1-3 and Comparative Examples 1-3 were mixed respectively with lithium carbonate, wherein the molar ratio of Li:Co was controlled to be 1.06, and the mixture was subjected to high-temperature solid-phase sintering in a push-plate furnace at a sintering temperature of 1000 °C for 12 hours to obtain a lithium cobalt oxide positive electrode material respectively; The lithium cobalt oxide materials obtained from the examples and comparative examples served as the active material, acetylene black as the conductive agent, and PVDF as the binding agent. The active material, conductive agent, and binding agent were weighed in a 92:4:4 ratio and mixed. A certain amount of the organic solvent NMP was added to the mixture. The resulting mixture was then stirred and coated with aluminum foil to form a positive electrode sheet. The negative electrode was made from a metallic lithium sheet, and a CR2430 button cell battery was assembled in an argon-filled glove box. The battery was subjected to electrical performance testing in a CT2001 A blue battery test system. Test conditions: 3, 0-4, 48 V, test temperature 25±1 °C. The test results are shown in Table 1. Table 1 It can be seen in Table 1 that the cycle retention rate of the comparative examples was significantly lower than that of the examples. This is because the cobalt oxides obtained in the comparative examples only had a common coating, and their coating layer (zirconium / alumina) cannot form a close connection with the cobalt hydroxide base material. Therefore, in the long-term cycling process, the phenomenon of sputtering and detachment occurs, whereby the lithium cobalt oxide is re-exposed to the corroding electrolyte, thus affecting the cycling performance of the material. Examples of the present invention have been described in detail above, along with the drawings, but the present invention is not limited to the examples mentioned above, and various modifications may be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the examples of the present invention and the features of the examples may be combined with each other without conflict.

Claims

1. A method for preparing a heavily coated cobalt oxide, comprising the following steps: S1: Adding a cobalt salt solution, a sodium hydroxide solution, and aqueous ammonia in parallel to a base solution to react, until the reaction material reaches the target particle size, aging the mixture, then subjecting the resulting mixture to solid-liquid separation to obtain a precipitate, and washing and drying the precipitate to obtain a dry material; S2: Adding the dry material and the hydroxide to an organic metal carboxylate solution, heating the mixture to evaporate the solvent, and when the solvent evaporation rate reaches more than 90%, heating the mixture to 180-200 °C to react; wherein the hydroxide is zirconium hydroxide or aluminum hydroxide,and the organic metal carboxylate solution is an alcoholic solution of zirconium alkyl carboxylate or aluminum alkyl carboxylate; S3: calcine the product after the reaction of step S2 in an oxygen atmosphere to obtain cobalt oxide.

2. The method according to claim 1, wherein in step S1, the concentration of the cobalt salt solution is 1.0-2.0 mol / L, and the concentration of the sodium hydroxide solution is 4.0-10.0 mol / L.

3. The method according to claim 1, wherein in step S1, the base solution is a mixed solution of sodium hydroxide and aqueous ammonia, the pH of the base solution is 10-11, and the concentration of ammonia is 5.0-10.0 g / L.

4. The method according to claim 1, wherein in step S1, the reaction temperature is controlled to be 55-65 °C, the pH of the reaction material is controlled to be 10-11,and the ammonia concentration is controlled to be 5-10 g / L.

5. The method according to claim 1, wherein in step S2, the ratio of the weight of the dry material to the volume of the organic metal carboxylate solution is 1 g:(1-5) mL, and the concentration of the metal carboxylate in the organic ethyl carboxylate solution is 0.1-0.2 mol / L.

6. The method according to claim 1, wherein in step S2, the amount of hydroxide added is 1-5% of the weight of the dry material.

7. The method according to claim 1, wherein in step S2, the number of carbon atoms in the alkyl segment of the zirconium alkyl carboxylate or the aluminum alkyl carboxylate is 6-10.

8. The method according to claim 1, wherein in step S2, the reaction time is 15-30 min.

9. The method according to claim 1, wherein in step S3,The calcination temperature is 500-750 °C.

10. Use of the method according to any of claims 1-9 in the preparation of lithium cobalt oxide or lithium-ion batteries.

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