Template growth method for preparing the lithium cobaltate precursor and its use

Abstract

A template growth method is provided for preparing a lithium cobaltate precursor and its use.The method comprises: S1: mixing an aqueous solution of ammonium metavanadate with a polyvinylpyrrolidone solution for hydrothermal reaction, and calcining the resulting precipitate under an aerobic atmosphere to obtain a vanadium pentoxide structure-directing agent, wherein the polyvinylpyrrolidone solution is prepared by dissolving polyvinylpyrrolidone in an alcohol; S2: adding the vanadium pentoxide structure-directing agent to a cobalt salt solution to obtain a turbid liquid, adding the turbid liquid, a carbonate solution, and a complexing agent in parallel flow mode for reaction, and performing aging when the reaction material reaches a target particle size; and S3: performing solid-liquid separation on the aged material, and anaerobically calcining the resulting precipitate prior to aerobic calcination to obtain a lithium cobaltate precursor.The method is also described for use in the preparation of a lithium cobalt or lithium-ion battery. Vanadium pentoxide is used as a seed crystal for coprecipitation to obtain a precursor with good crystallinity, thereby improving the material's cycle performance. Meanwhile, vanadium is doped into a lithium cobalt material, giving the material good lattice stability and a relatively high specific capacity.

Description

Template growth method for preparing the lithium cobaltate precursor and its use Technical Field This disclosure pertains to the technical field of lithium battery cathode materials, and specifically relates to a method for preparing a lithium cobalt oxide (LCO) precursor by template-induced growth and its use. Background With advantages such as high specific energy, light weight, and environmental friendliness, lithium-ion batteries (LIBs) have been widely used in digital products, household appliances, electric vehicles, aerospace, satellites, and weaponry, to name just a few, and are playing an increasingly important role in the civil, aerospace, and military fields. As portable electronic devices, such as mobile phones, digital cameras, and laptops, become increasingly smaller, lighter, and thinner, the market is setting ever higher standards for energy density, electrochemical performance, and safety of LIBs. The LiCoO2 (lithium cobalt oxide, LCO) cathode material has advantages such as high voltage plateau, excellent cycle performance, and high compact density, making it one of the first commercially available cathode materials. However, due to the LCO structure, when the charging voltage exceeds 4.2 V, the disintercalation coefficient x of Li1-xCoO2 becomes greater than or equal to 0.5, causing its internal structure to collapse. This leads to several problems, including poor charge and discharge cycles and poor high-temperature storage performance at high voltages. Therefore, to improve a battery's discharge capacity and energy density by increasing its charge cutoff voltage, it is first necessary to modify these cathode materials to address the many issues caused by the increased cutoff voltage. Doping a lithium-ion (LCO) material can improve its structural stability before and after a charge-discharge process, inhibit phase transition generation, and increase the material's lithium desaturation, capacitance, and electrical conductivity. According to crystal chemistry theory, doping with a small amount of a foreign element sometimes leads to crystal defects, which can increase the diffusion rate of ions in a bulk phase. According to energy band theory, a pon-type semiconductor can be produced by doping a semiconductor compound with high-valence or low-valence ions, which can increase the crystal's electrical conductivity. In recent years, researchers have explored the influence of doping with different metallic elements (Mg, Al, and Zr) on the electrochemical performance of an LCO cathode material.However, there are few reports on LCO cathode materials doped with a small amount of vanadium. Brief Description of the Invention The purpose of this disclosure is to address at least one of the technical problems in the prior art. To this end, this disclosure provides a method for preparing and using an LCO precursor by template-induced growth. In the method, a vanadium pentoxide particle was prepared beforehand as a template, and then vanadium was added during co-precipitation to obtain a vanadium-doped LCO precursor. According to one aspect of this disclosure, a method is provided for preparing an LCO precursor by template-induced growth, which includes the following steps: S1: mixing an aqueous solution of ammonium metavanadate (MVA) with a solution of polyvinylpyrrolidone (PVP) to allow a hydrothermal reaction, and subjecting a resulting precipitate to calcination in an aerobic atmosphere to obtain a template of vanadium pentoxide, wherein the PVP solution is prepared by dissolving PVP in an alcohol; S2: Add the vanadium pentoxide template to a cobalt salt solution to obtain a suspension, simultaneously feed the suspension, a carbonate solution and a complexing agent to enable a reaction, and when the particle size of a resulting reaction system reaches a target value, age; and S3: Perform solid-liquid separation (SLS) to obtain a precipitate, and subject the precipitate first to anaerobic calcination and then to aerobic calcination to obtain the LCO precursor. In some embodiments of the present disclosure, in S1, the aqueous solution of MVA can be prepared by dissolving the MVA in water; and the MVA, water, PVP, and alcohol can be in a ratio of (1-3) g: (25-35) mL: (8-12) g: (90-110) mL. In some preferred embodiments of the present disclosure, in S1, the alcohol may be ethylene glycol (EG). In some embodiments of the present disclosure, in S1, the hydrothermal reaction can be carried out at 170 °C to 190 °C for 20 to 28 h. In some embodiments of this disclosure, in S1, the vanadium pentoxide template can have a particle size of 50 nm to 100 nm. The vanadium pentoxide template is microspherical, and its particle size cannot be too large or too small. If the template has too small a particle size, it will dissolve too quickly and cannot perform well as a seed crystal. If the template has too large a particle size, the dissolution will be too slow, and less cobalt vanadate will be produced. Therefore, when the vanadium pentoxide has a particle size of 50 nm to 100 nm, it can be ensured that the vanadium pentoxide dissolves and produces a precipitate of cobalt vanadate simultaneously, while also serving as a template. In some embodiments of the present disclosure, in S1, calcination can be carried out at 450 °C to 550 °C for 1 h 3 h. In some embodiments of the present disclosure, in S2, the cobalt salt solution may have a concentration of 1.0 mol / L to 2.0 mol / L; and a molar ratio of cobalt in the cobalt salt solution with vanadium in the vanadium pentoxide template may be 10:(0, 1-2). In some embodiments of this disclosure, in S2, the cobalt salt solution may be at least one selected from the group consisting of a cobalt sulfate solution, a cobalt nitrate solution, and a cobalt chloride solution. In some embodiments of this disclosure, in S2, the carbonate solution may be a sodium carbonate solution with a concentration of 1.0 mol / L to 2.0 mol / L. In some embodiments of this disclosure, in S2, the complexing agent may be ammonium hydroxide with a concentration of 6.0 mol / L to 12.0 mol / L. In some embodiments of the present disclosure, in S2, the reaction can be carried out at a pH of 8 to 9, a temperature of 70 °C to 80 °C and an ammonia concentration of 5 g / L to 10 g / L. In some embodiments of the present disclosure, in S2, the reaction can be carried out at a stirring speed of 200 rpm to 500 rpm. In some realizations of this disclosure, in S2, aging can be carried out from 48 to 72 hours. In some embodiments of the present disclosure, in S2, the target value of the particle size of the reaction system can be 4.0 m or 8.0 m. In some embodiments of the present disclosure, in S3, prior to anaerobic calcination, the precipitate may be further washed with water and dried; and the drying may be carried out at 100 °C to 200 °C for 10 to 30 h. In some embodiments of the present disclosure, in S3, anaerobic calcination can be carried out as follows: introduce an inert gas, heat from ambient temperature to a temperature of 200 °C to 300 °C at a heating rate of 0.5 °C / min to 10 °C / min and maintain the temperature for 4 to 6 h, and heat to a temperature of 600 °C to 800 °C and maintain the temperature for 1 to 2 h; and aerobic calcination can be carried out as follows: introduce an oxidizing gas and maintain the temperature of 600 °C to 800 °C for 4 to 6 h. The method described above is also used in the preparation of LCO or LIB in this disclosure. In some embodiments of this disclosure, a method for preparing LCO may include: mixing the LCO precursor with a lithium source, and roasting a resulting mixture in an aerobic atmosphere. In some embodiments of this disclosure, the lithium source may be at least one selected from the group consisting of lithium carbonate, lithium hydroxide, lithium nitrate, and lithium oxalate. In some embodiments of the present disclosure, a molar ratio of cobalt in the LCO precursor to lithium in the lithium source may be 1: (1, 0-1, 2) . In some embodiments of the present disclosure, roasting can be carried out at 900 °C to 1,200 °C for 6 to 18 h. According to a preferred embodiment of this disclosure, this disclosure has at least the following beneficial effects: 1. In this disclosure, a nanoscale vanadium pentoxide template is first prepared via a hydrothermal reaction. The vanadium pentoxide is then mixed with a cobalt salt solution. The resulting mixture is co-precipitated with a carbonate solution and a complexing agent to obtain vanadium-doped basic cobalt carbonate. The vanadium-doped basic cobalt carbonate is then calcined to obtain an LCO precursor. The LCO precursor can be sintered with a lithium source to obtain an LCO cathode material. 2. Vanadium pentoxide templates are difficult to dissolve in cobalt salt solutions. Therefore, during co-precipitation, cobalt ions react with carbonate and hydroxide ions to produce basic cobalt carbonate. Co-precipitation continues with the vanadium pentoxide template acting as a seed crystal to obtain a cobalt carbonate precipitate with high crystallinity. When preparing an LCO cathode material by subsequent sintering, this high crystallinity can be maintained to prevent cracking of the LCO material and improve the material's cycle performance.Furthermore, during co-precipitation, vanadium pentoxide readily dissolves in a slightly alkaline solution to produce metavanadate, and the metavanadate reacts further with cobalt ions in solution to produce cobalt vanadate, such that the anion is replaced by vanadium to yield a vanadium-doped LCO precursor. When the LCO precursor is sintered with a lithium source, the cobalt vanadate undergoes a further crystallization reaction to yield a vanadium-doped LCO cathode material. 3. Due to the doping of high valency vanadium, the prepared LCO cathode material exhibits excellent lattice stability and high specific capacity during a charge-discharge process. Brief Description of the Drawings This disclosure is described below with reference to the accompanying drawings and examples. FIGURE 1 is a scanning electron microscopy (SEM) image of the LCO prepared in example 1 of this disclosure. Detailed Description of the Invention The technical concepts and effects of this disclosure are clearly and completely described below, along with examples, so that its objectives, features, and effects can be fully understood. The examples described herein are merely some, rather than all, of the examples in this disclosure. All other examples obtained by persons skilled in the art based on the examples in this disclosure without creative effort should fall within the scope of protection of this disclosure. Preparation of a vanadium pentoxide template: MVA, deionized water, PVP K30, and EG were taken according to a ratio of 1 g: 30 mL: 10 g: 100 mL; MVA was dissolved in deionized water to obtain an MVA solution, and PVP K30 was dissolved in EG to obtain a PVP solution; the MVA solution and the PVP solution were mixed and transferred to a hydrothermal reactor to undergo a reaction at 180 °C for 24 h; and a resulting precipitate was washed and then calcined at 500 °C for 2 h in an air atmosphere to obtain the anodium pentoxide microspherical template with a particle size of 50 nm to 100 nm. Example 1 In this example, an LCO cathode material was prepared, and a specific preparation process was as follows: Phase 1 According to a cobalt-to-vanadium molar ratio of 10:0.1, the vanadium pentoxide template was added to a cobalt sulfate solution with a concentration of 2.0 mol / L, and the resulting mixture was thoroughly mixed to obtain a mixed solution. Phase 2 A sodium carbonate solution with a concentration of 2.0 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide with a concentration of 12.0 mol / L was prepared as a complexing agent. Phase 4 The mixed solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 200 rpm, a pH of 8, a temperature of 70 °C, and an ammonia concentration of 5 g / l. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 8.0 m, feeding was stopped and aging was carried out for 48 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 100 °C for 30 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 200 °C at a heating rate of 10 °C / min and held for 6 h, then raised to 600 °C and held for 2 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 600 °C was held for 6 h; and a product was cooled, crushed and sieved to obtain an LCO precursor material. Phase 8: According to a cobalt-to-lithium molar ratio of 1:1, the LCO precursor material obtained in phase 7 was mixed with lithium carbonate, and the resulting mixture was roasted at 900 °C for 18 hours in an air atmosphere, then crushed, sieved, and subjected to iron removal to obtain the LCO cathode material. Figure 1 is an SEM image of the LCO prepared in this example, and it can be seen from the figure that the LCO particles have a very compact blocky structure and are not easily broken down. Example 2 In this example, an LCO cathode material was prepared, and a specific preparation process was as follows: Phase 1 According to a cobalt-to-vanadium molar ratio of 10:1, the vanadium pentoxide template was added to a cobalt nitrate solution with a concentration of 1.5 mol / L, and the resulting mixture was thoroughly mixed to obtain a mixed solution. Phase 2 A sodium carbonate solution with a concentration of 1.5 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide was prepared with a concentration of 9.0 mol / L as a complexing agent. Phase 4 The mixed solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 350 rpm, a pH of 8.5, a temperature of 75 °C, and an ammonia concentration of 8 g / L. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 6.0 m, feeding was stopped and aging was carried out for 60 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 150 °C for 20 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 250 °C at a heating rate of 5 °C / min and held for 5 h, then raised to 700 °C and held for 1.5 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 700 °C was held for 5 h; and the product was cooled, crushed, and sieved to obtain an LCO precursor material. Phase 8 According to a cobalt-to-lithium molar ratio of 1:1, 1, the LCO precursor material obtained in phase 7 was mixed with lithium hydroxide, and a resulting mixture was roasted at 1,050 °C for 12 hours in an air atmosphere, then crushed, sieved and subjected to iron removal to obtain the LCO cathode material. Example 3 In this example, an LCO cathode material was prepared, and a specific preparation process was as follows: Phase 1 According to a cobalt-to-vanadium molar ratio of 10:2, the vanadium pentoxide template was added to a cobalt chloride solution with a concentration of 1.0 mol / L, and the resulting mixture was thoroughly mixed to obtain a mixed solution. Phase 2 A sodium carbonate solution with a concentration of 1.0 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide was prepared with a concentration of 6.0 mol / L as a complexing agent. Phase 4 The mixed solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 500 rpm, a pH of 9, a temperature of 80 °C, and an ammonia concentration of 10 g / L. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 4.0 m, feeding was stopped and aging was carried out for 72 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 200 °C for 10 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 300 °C at a heating rate of 10 °C / min and held for 4 h, then raised to 800 °C and held for 1 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 800 °C was held for 4 h; and a product was cooled, crushed and sieved to obtain an LCO precursor material. Phase 8 According to a cobalt-to-lithium molar ratio of 1:1, the LCO precursor material obtained in phase 7 was mixed with lithium nitrate, and a resulting mixture was roasted at 1,200 °C for 6 hours in an air atmosphere, then crushed, sieved and subjected to iron removal to obtain the LCO cathode material. Comparative Example 1 In this comparative example, an LCO cathode material was prepared, which differed from Example 1 in that the vanadium pentoxide template was not added. A specific preparation process was as follows: Phase 1 A cobalt sulfate solution was prepared with a concentration of 2.0 mol / L. Phase 2 A sodium carbonate solution with a concentration of 2.0 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide with a concentration of 12.0 mol / L was prepared as a complexing agent. Phase 4 The cobalt sulfate solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 200 rpm, a pH of 8, a temperature of 70 °C, and an ammonia concentration of 5 g / L. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 8.0 m, feeding was stopped and aging was carried out for 48 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 100 °C for 30 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 200 °C at a heating rate of 10 °C / min and held for 6 h, then raised to 600 °C and held for 2 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 600 °C was held for 6 h; and a product was cooled, crushed and sieved to obtain an LCO precursor material. Phase 8 According to a cobalt-to-lithium molar ratio of 1:1, the LCO precursor material obtained in phase 7 was mixed with lithium carbonate, and a resulting mixture was roasted at 900 °C for 18 hours in an air atmosphere, then crushed, sieved and subjected to iron removal to obtain the LCO cathode material. Comparative Example 2 In this comparative example, an LCO cathode material was prepared, which differed from Example 2 in that the vanadium pentoxide template was not added. A specific preparation process was as follows: Phase 1 A cobalt nitrate solution was prepared with a concentration of 1.5 mol / L. Phase 2 A sodium carbonate solution with a concentration of 1.5 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide was prepared with a concentration of 9.0 mol / L as a complexing agent. Phase 4 The cobalt nitrate solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 350 rpm, a pH of 8.5, a temperature of 75 °C, and an ammonia concentration of 8 g / L. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 6.0 m, feeding was stopped and aging was carried out for 60 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 150 °C for 20 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 250 °C at a heating rate of 5 °C / min and held for 5 h, then raised to 700 °C and held for 1.5 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 700 °C was held for 5 h; and a product was cooled, crushed and sieved to obtain an LCO precursor material. Phase 8 According to a cobalt-to-lithium molar ratio of 1:1, 1, the LCO precursor material obtained in phase 7 was mixed with lithium hydroxide, and a resulting mixture was roasted at 1,050 °C for 12 hours in an air atmosphere, then crushed, sieved and subjected to iron removal to obtain the LCO cathode material. Comparative Example 3 In this comparative example, an LCO cathode material was prepared, which differed from Example 3 in that the vanadium pentoxide template was not added. A specific preparation process was as follows: Phase 1 A cobalt chloride solution was prepared with a concentration of 1.0 mol / L. Phase 2 A sodium carbonate solution with a concentration of 1.0 mol / L was prepared as a precipitating agent. Phase 3 Ammonium hydroxide was prepared with a concentration of 6.0 mol / L as a complexing agent. Phase 4 The cobalt chloride solution prepared in phase 1, the sodium carbonate solution prepared in phase 2, and the ammonium hydroxide prepared in phase 3 were fed simultaneously into a reactor to allow a reaction at a stirring speed of 500 rpm, a pH of 9, a temperature of 80 °C, and an ammonia concentration of 10 g / L. Phase 5 When the D50 of a resulting precipitate in the reactor was detected to have reached 4.0 m, feeding was stopped and aging was carried out for 72 h. Phase 6 The precipitate in the reactor was separated through SLS, washed with pure water and dried at 200 °C for 10 h. Phase 7 The dried precipitate was placed in a tube furnace; an inert gas was introduced into the tube furnace for protection, and the temperature was raised from ambient temperature to 300 °C at a heating rate of 10 °C / min and held for 4 h, then raised to 800 °C and held for 1 h; then an oxidizing gas was introduced instead of the inert gas, and the temperature of 800 °C was held for 4 h; and a product was cooled, crushed and sieved to obtain an LCO precursor material. Phase 8 According to a cobalt-to-lithium molar ratio of 1:1, the LCO precursor material obtained in phase 7 was mixed with lithium nitrate, and a resulting mixture was roasted at 1,200 °C for 6 hours in an air atmosphere, then crushed, sieved and subjected to iron removal to obtain the LCO cathode material. Test example The LCO cathode material obtained from each of the examples and comparative examples, acetylene black (as a conducting agent), and polyvinylidene fluoride (PVDF) (as a binder) were weighed and mixed in a 92:4:4 ratio. A specified amount of the organic solvent N-methylpyrrolidone (NMP) was then added, and the resulting mixture was stirred and coated onto an aluminum foil to obtain a positive electrode sheet. A CR2430 button cell battery was then assembled in an argon-filled glove box using a metallic lithium foil as the negative electrode. An electrical performance test was performed on a CT2001A Land test system under the following conditions: Voltage: 3.0 V to 4.48 V, current density: 1 C = 180 mAh / g, and test temperature: 25 ± 1 °C. The test results are shown in Table 1. Table 1 Electrochemical yield of LCO Table 1 shows that the discharge capacity and cycle performance of the examples are significantly higher than those of the comparative examples, which is attributed to the addition of the vanadium pentoxide template. When vanadium pentoxide is used as a seed crystal for co-precipitation, a precursor with prominent crystallinity is obtained. The LCO cathode material obtained by sintering this precursor inherits this prominent crystallinity, making the LCO cathode material difficult to break and improving its cycle performance.Furthermore, vanadium pentoxide can be dissolved to produce metavanadate during co-precipitation, and the metavanadate reacts with cobalt ions to produce cobalt vanadate, so that vanadium is gently doped into the LCO material, giving the cathode material prominent lattice stability and high specific capacity. The examples in this disclosure are described in detail with reference to the accompanying drawings, but this disclosure is not limited to the examples above. Within the scope of knowledge of those skilled in the art, various changes may also be made without departing from the purpose of this disclosure. Furthermore, the examples in this disclosure and the features of the examples may be combined with each other in a non-conflicting situation.

Claims

1. A method for preparing a lithium cobalt oxide (LCO) precursor via template-induced growth, comprising the following steps: S1: mixing an aqueous solution of ammonium metavanadate with a polyvinylpyrrolidone solution to enable a hydrothermal reaction, and subjecting the resulting precipitate to calcination in an aerobic atmosphere to obtain a vanadium pentoxide template, wherein the polyvinylpyrrolidone solution is prepared by dissolving polyvinylpyrrolidone in an alcohol; S2: adding the vanadium pentoxide template to a cobalt salt solution to obtain a suspension, simultaneously feeding the suspension, a carbonate solution, and a complexing agent to enable a reaction, and when the particle size of the resulting reaction system reaches a target value, aging; and S3: performing solid-liquid separation to obtain a precipitate,and subjecting the precipitate first to anaerobic calcination and then to aerobic calcination to obtain the LCO precursor.

2. The method according to claim 1, wherein in S1, the aqueous ammonium metavanadate solution is prepared by dissolving ammonium metavanadate in water; and the ammonium metavanadate, water, polyvinylpyrrolidone, and alcohol are in a ratio of (1-3) g: (25-35) mL: (8-12) g: (90-110) mL.

3. The method according to claim 1, wherein in S1, the hydrothermal reaction is carried out at 170 °C to 190 °C for 20 to 28 h.

4. The method according to claim 1, wherein in S1, the vanadium pentoxide template has a particle size of 50 nm to 100 nm.

5. The method according to claim 1, wherein in S2, the cobalt salt solution has a concentration of 1.0 mol / L to 2.0 mol / L; and a molar ratio of cobalt in the cobalt salt solution to vanadium in the vanadium pentoxide template is 10:(0,1-2).

6. The method according to claim 1, wherein in S2, the carbonate solution is a sodium carbonate solution with a concentration of 1.0 mol / L to 2.0 mol / L.

7. The method according to claim 1, wherein in S2, the reaction is carried out at a pH of 8 to 9, a temperature of 70 °C to 80 °C, and an ammonia concentration of 5 g / L to 10 g / L.

8. The method according to claim 1, wherein in S2, the aging is carried out for 48 to 72 h.

9. The method according to claim 1, wherein in S3, the anaerobic calcination is carried out as follows: introduce an inert gas, heat from ambient temperature to a temperature of 200 °C to 300 °C at a heating rate of 0.5 °C / min to 10 °C / min and maintain the temperature for 4 to 6 h,and heating to a temperature of 600 °C to 800 °C and maintaining the temperature for 1 to 2 h; and aerobic calcination is carried out as follows: introducing an oxidizing gas, and maintaining the temperature of 600 °C to 800 °C for 4 to 6 h.

10. Use of the method according to any of claims 1 to 9 in the preparation of LCO or a lithium-ion battery.

Images