Α-cobalt hydroxide, preparation method therefor, and use thereof

Abstract

Provided are α-cobalt hydroxide, a preparation method therefor, and the use thereof. The preparation method comprises the following steps: (1) mixing a cobalt salt, an intercalation agent and a solvent to obtain a mixed solution; and (2) injecting in parallel flow the mixed solution and a caustic soda solution into a base solution to undergo a coprecipitation reaction, so as to obtain a cobalt hydroxide slurry; and (3) carrying out solid-liquid separation on the cobalt hydroxide slurry, washing same with a washing agent containing the intercalation agent, and drying same to obtain α-cobalt hydroxide. Mixing the cobalt salt and the intercalation agent first, and then performing the coprecipitation reaction with the caustic soda solution enable the cobalt hydroxide structure to be stably generated, and prevent interlayer collapse, thereby obtaining spherical α-cobalt hydroxide which has perfect crystallinity and dense primary particle intercalation.

Description

Alpha-cobalt hydroxide, preparation method and application thereof Technical Field

[0001] The present disclosure belongs to the technical field of battery materials and relates to α-cobalt hydroxide and a preparation method and application thereof. Background Art

[0002] With the popularization of mobile electronic devices and hybrid vehicles, the further development of lithium-ion batteries has been greatly promoted. Among them, lithium cobalt oxide has been widely used in the 3C market due to its advantages such as stable structure, high specific capacity, and high voltage platform. However, when the cut-off voltage of lithium cobalt oxide is greater than 4.5V, the cathode will undergo a transformation from the O3 phase to the H1-3 phase. Although these phase changes are reversible, the transformation from ordered to disordered will greatly reduce the diffusion coefficient of Li+, resulting in a decrease in cycle performance and rate performance. Currently, most lithium cobalt oxides on the market are prepared by solid-phase sintering. This method has high requirements for the precursor and requires good morphology and electrochemical properties. Cobalt hydroxide, as an important precursor for the synthesis of lithium cobalt oxide, can inherit its own structure well when mixed lithium is sintered into lithium cobalt oxide. The structure and morphology of the cobalt hydroxide precursor have an extremely important influence on the performance of lithium cobalt oxide. Among them, the cobalt hydroxide precursor has two crystal structures, α-type and β-type. The two structures are synthesized by different methods. Compared with the β-cobalt hydroxide with brucite structure, the α-cobalt hydroxide with hydrotalcite structure has a larger interplanar spacing, which facilitates the flow of electrons and thus has good electrical conductivity. After sintering into lithium cobalt oxide, its performance is better than that of β-cobalt hydroxide.

[0003] Existing synthesis methods typically use liquid alkali and cobalt metal liquid for direct precipitation. Initially, the material exhibits a green / light blue α-cobalt hydroxide with a 001 interlayer spacing greater than 0.7 nm. During the subsequent reaction, due to the poor stability of α-cobalt hydroxide, the interlayers gradually collapse, transforming it into a pink β-cobalt hydroxide. The 001 interlayer spacing decreases from 0.7 nm to 0.46 nm, reducing the material's activity. After sintering to lithium cobalt oxide, the performance is lower than that of α-cobalt hydroxide. Furthermore, samples without glucose addition exhibit loose intercalation and low TD. Even if the newly generated α-cobalt hydroxide can be removed promptly at the initial stage of the reaction, the material's particle size is very small and its crystallinity is very poor, making it difficult to sinter lithium cobalt oxide cathode materials. Therefore, it is difficult to prepare stable, high-purity α-cobalt hydroxide directly through alkali precipitation.

[0004] CN112624206A discloses a method for preparing spherical α-cobalt hydroxide. This method uses an organic amine as a precipitant, producing relatively stable spherical α-cobalt hydroxide without the addition of additional metal ions or complexing agents. The raw material components are simple and inexpensive, and the organic amine can be recycled, reducing production costs. However, the synthesized sample exhibits a relatively loose morphology and poor XRD crystallinity, which negatively impacts the performance of the sintered lithium cobalt oxide.

[0005] CN111559762A discloses a method for preparing cobalt hydroxide, comprising the following steps: (1) adding a cobalt salt solution and an ammonia solution to deionized water at 30-75° C., controlling the pH of the reaction system to 6-9, and obtaining α-cobalt hydroxide. The obtained α-cobalt hydroxide is very easily converted into a stable β-cobalt hydroxide, and the activity of the material will be significantly reduced.

[0006] The α-cobalt hydroxide obtained by the method described in the above scheme has a loose morphology or poor stability, and it is difficult to obtain a lithium cobalt oxide positive electrode material with excellent performance.

[0007] Summary of the Invention

[0008] The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

[0009] The present invention aims to provide an α-cobalt hydroxide, a preparation method, and an application thereof. The present invention provides a method for preparing α-cobalt hydroxide. The method comprises pre-mixing a cobalt salt with an interlayer intercalator and then subjecting the mixture to a coprecipitation reaction with an alkaline solution. This method can stabilize the structure of the cobalt hydroxide, avoid interlayer collapse, and obtain spherical α-cobalt hydroxide with intact crystallinity and tightly intercalated primary particles.

[0010] To achieve this purpose, the present disclosure adopts the following technical solutions:

[0011] In a first aspect, the present disclosure provides a method for preparing α-cobalt hydroxide, the preparation method comprising the following steps:

[0012] (1) mixing a cobalt salt, an intercalation agent, and a solvent to obtain a mixed solution;

[0013] (2) injecting the mixed solution and liquid caustic soda into the bottom liquid in parallel to carry out a coprecipitation reaction to obtain a cobalt hydroxide slurry;

[0014] (3) The cobalt hydroxide slurry is separated into solid and liquid, washed with a detergent containing an intercalating agent, and dried to obtain the α-cobalt hydroxide.

[0015] The present invention uses liquid alkali and cobalt metal liquid for precipitation, and adds an interlayer intercalator to the cobalt salt solution to form a sheet-intercalated spherical morphology of cobalt hydroxide. The interlayer intercalator has a diameter of about 0.3nm and can be used as an interlayer intercalator to be inserted into the uncollapsed α-cobalt hydroxide layers. The hydroxyl groups on both sides of the interlayer intercalator can form hydrogen bonds with the hydroxyl groups of cobalt hydroxide, making the α-cobalt hydroxide structure more stable, thereby obtaining a spherical α-cobalt hydroxide with intact crystallinity and tightly intercalated primary particles. The use of a detergent containing an interlayer intercalator can not only avoid the oxidation of cobalt hydroxide, but also further maintain the stability of α-cobalt hydroxide, thereby inhibiting the phase transformation of α-cobalt hydroxide at the root.

[0016] In one embodiment, the cobalt salt in step (1) includes any one of cobalt chloride, cobalt sulfate or cobalt nitrate, or a combination of at least two thereof.

[0017] In one embodiment, the intercalator comprises glucose.

[0018] The present invention uses glucose as an interlayer intercalator. The molecular particle size of the glucose is suitable and can be perfectly embedded in the interlayer of α-cobalt hydroxide to play a supporting role. The hydroxyl groups of the glucose molecules can form hydrogen bonds with the hydroxyl groups of the interlayer of α-cobalt hydroxide, further stabilizing the structure.

[0019] In one embodiment, the concentration of the cobalt salt in the mixed solution is 90-130 g / L, for example, 90 g / L, 100 g / L, 110 g / L, 120 g / L or 130 g / L.

[0020] In one embodiment, the concentration of the intercalant in the mixed solution is 0.5 to 2 g / L, for example, 0.5 g / L, 0.8 g / L, 1 g / L, 1.5 g / L or 2 g / L.

[0021] In one embodiment, the concentration of the alkali solution in step (2) is 100-400 g / L, for example, 100 g / L, 150 g / L, 200 g / L, 300 g / L or 400 g / L.

[0022] In one embodiment, the base solution comprises sodium hydroxide.

[0023] In one embodiment, the pH of the base solution is 9.5 to 10.5, for example, 9.5, 9.8, 10, 10.2 or 10.5.

[0024] In one embodiment, the temperature of the base liquid is 40-50°C, for example, 40°C, 42°C, 45°C, 48°C or 50°C.

[0025] In one embodiment, the stirring speed of the coprecipitation reaction in step (2) is 200-500 rpm, for example, 200 rpm, 250 rpm, 300 rpm, 400 rpm or 500 rpm.

[0026] In one embodiment, the atmosphere of the co-precipitation reaction comprises nitrogen.

[0027] In one embodiment, the flow rate of the nitrogen is 10 to 20 L / min, for example, 10 L / min, 12 L / min, 15 L / min, 18 L / min or 20 L / min.

[0028] In one embodiment, the pH of the coprecipitation reaction in step (2) is 8 to 9, for example, 8, 8.2, 8.5, 8.8 or 9.

[0029] In one embodiment, the endpoint of the coprecipitation reaction is that the particle size of the particles in the system is 5 to 22 μm, for example, 5 μm, 8 μm, 10 μm, 15 μm or 22 μm.

[0030] In one embodiment, the concentration of the intercalant in the detergent in step (3) is 0.05 to 1 g / L, for example, 0.05 g / L, 0.08 g / L, 0.1 g / L, 0.5 g / L or 1 g / L.

[0031] In one embodiment, the volume ratio of the detergent to the cobalt hydroxide slurry is (0.5-1.5):1, for example: 0.5:1, 0.8:1, 1:1, 1.2:1 or 1.5:1, etc.

[0032] In one embodiment, the drying equipment in step (3) comprises any one of a vacuum oven, a nitrogen furnace or a muffle furnace, or a combination of at least two of them.

[0033] In one embodiment, the drying temperature is 100-120°C, for example, 100°C, 105°C, 110°C, 115°C or 120°C.

[0034] In one embodiment, the drying time is 16 to 20 hours, for example, 16 hours, 17 hours, 18 hours, 19 hours or 20 hours.

[0035] In one embodiment, the drying is followed by screening.

[0036] In one embodiment, the mesh size of the sieve is 200-400 mesh, for example, 200 mesh, 250 mesh, 300 mesh, 350 mesh or 400 mesh.

[0037] In a second aspect, the present disclosure provides an α-cobalt hydroxide, which is prepared by the method described in the first aspect.

[0038] The α-cobalt hydroxide prepared by the method disclosed herein is spherical, has good crystallinity, and has primary particles that are tightly intercalated.

[0039] In a third aspect, the present disclosure provides a lithium cobaltate, which is prepared by mixing and sintering the α-cobalt hydroxide described in the second aspect and a lithium source.

[0040] In a fourth aspect, the present disclosure provides a lithium-ion battery, wherein the lithium-ion battery comprises the lithium cobalt oxide as described in the third aspect.

[0041] Compared with the prior art, the present disclosure has the following beneficial effects:

[0042] (1) The present invention adds glucose as an interlayer intercalator. Benefiting from its appropriate molecular size (0.3 nm), it can be perfectly embedded in the interlayer of α-cobalt hydroxide, playing the role of supporting the structure. The hydroxyl groups of the glucose molecules can form hydrogen bonds with the hydroxyl groups between the α-cobalt hydroxide layers, further stabilizing the structure and avoiding interlayer collapse. During the washing process, the glucose solution is used again as a detergent, which not only avoids the oxidation of cobalt hydroxide, but also further maintains the stability of α-cobalt hydroxide, thereby fundamentally inhibiting the phase transition of α-cobalt hydroxide, and finally obtaining spherical α-cobalt hydroxide with intact crystallinity and tightly intercalated primary particles.

[0043] (2) The first-week discharge specific capacity of the lithium cobalt oxide battery made using the α-cobalt hydroxide disclosed in the present invention can reach more than 194.9 mAh / g, and the capacity retention rate of 25 cycles at 1C can reach more than 87.2%.

[0044] Still other aspects will become apparent upon reading and understanding the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are used to provide a further understanding of the technical solution of this article and constitute a part of the specification. Together with the embodiments of this application, they are used to explain the technical solution of this article and do not constitute a limitation on the technical solution of this article.

[0046] FIG1 is a SEM image of α-cobalt hydroxide obtained in Example 1.

[0047] FIG2 is a SEM image of α-cobalt hydroxide obtained in Example 2.

[0048] FIG3 is a SEM image of α-cobalt hydroxide obtained in Example 3.

[0049] FIG4 is a SEM image of cobalt hydroxide obtained in Comparative Example 1.

[0050] FIG5 is a SEM image of cobalt hydroxide obtained in Comparative Example 2.

[0051] FIG6 is a comparison of XRD patterns of cobalt hydroxides obtained in Example 1-3 and Comparative Example 1-2. DETAILED DESCRIPTION

[0052] The technical solution of the present disclosure is further described below through specific implementation methods. Those skilled in the art should understand that the embodiments are only used to help understand the present disclosure and should not be regarded as specific limitations of the present disclosure.

[0053] Example 1

[0054] This embodiment provides an α-cobalt hydroxide, which is prepared by the following method:

[0055] (1) mixing cobalt chloride, glucose, and water to obtain a mixed solution having a cobalt chloride concentration of 130 g / L and a glucose concentration of 0.5 g / L;

[0056] (2) Add 250 L of pure water to a 500 L reactor until the reactor is half full, start stirring at the same time, the speed is 400 rpm, turn on nitrogen, adjust the flow rate to 10 L / min, adjust the pH of the bottom liquid to 10, and adjust the bottom liquid temperature to 45 ° C. The mixed solution and 300 g / L of liquid caustic soda are injected into the reactor in parallel, maintaining the reaction pH at 8.5. After the reactor is full, start suction filtration, maintain the reactor liquid level near the overflow port, and stop adding liquid until the particle size grows to 20 μm to obtain cobalt hydroxide slurry;

[0057] (3) The cobalt hydroxide slurry was centrifuged and washed with a 0.05 g / L glucose solution as the detergent (the volume ratio of the detergent to the cobalt hydroxide slurry was 1:1), and dried in a blast oven at 110° C. for 16 h. The dried material was sieved on a 300-mesh sieve to obtain the α-cobalt hydroxide.

[0058] The SEM image of the α-cobalt hydroxide is shown in FIG1 .

[0059] Example 2

[0060] This embodiment provides an α-cobalt hydroxide, which is prepared by the following method:

[0061] (1) mixing cobalt chloride, glucose, and water to obtain a mixed solution having a cobalt chloride concentration of 90 g / L and a glucose concentration of 1 g / L;

[0062] (2) Add 250 L of pure water to a 500 L reactor until the reactor is half full, start stirring at the same time, the speed is 200 rpm, turn on nitrogen, adjust the flow rate to 10 L / min, adjust the pH of the bottom liquid to 9.5, and adjust the bottom liquid temperature to 40 ° C. The mixed solution and 100 g / L of liquid caustic soda are injected into the reactor in parallel, maintaining the reaction pH at 8. After the reactor is full, start suction filtration, maintain the reactor liquid level near the overflow port, and stop adding liquid until the particle size grows to 5 μm to obtain cobalt hydroxide slurry;

[0063] (3) The cobalt hydroxide slurry was centrifuged and washed with a 0.1 g / L glucose solution as the detergent (the volume ratio of the detergent to the cobalt hydroxide slurry was 1.5:1), and dried in a blast oven at 100° C. for 20 h. The dried material was sieved on a 200-mesh sieve to obtain the α-cobalt hydroxide.

[0064] The SEM image of the α-cobalt hydroxide is shown in FIG2 .

[0065] Example 3

[0066] This embodiment provides an α-cobalt hydroxide, which is prepared by the following method:

[0067] (1) mixing cobalt chloride, glucose, and water to obtain a mixed solution having a cobalt chloride concentration of 110 g / L and a glucose concentration of 2 g / L;

[0068] (2) Add 250 L of pure water to a 500 L reactor until the reactor is half full, start stirring at the same time, the speed is 500 rpm, turn on nitrogen, adjust the flow rate to 20 L / min, adjust the pH of the bottom liquid to 10.5, and adjust the bottom liquid temperature to 50 ° C. The mixed solution and 300 g / L of liquid caustic soda are injected into the reactor in parallel, maintaining the reaction pH at 9.5. After the reactor is full, start suction filtration, maintain the reactor liquid level near the overflow port, and stop adding liquid until the particle size grows to 22 μm to obtain cobalt hydroxide slurry;

[0069] (3) The cobalt hydroxide slurry was centrifuged and washed with a 1 g / L glucose solution as the detergent (the volume ratio of the detergent to the cobalt hydroxide slurry was 1.5:1), and dried in a blast oven at 120° C. for 16 h. The dried material was sieved on a 400-mesh sieve to obtain the α-cobalt hydroxide.

[0070] The SEM image of the α-cobalt hydroxide is shown in FIG3 .

[0071] Example 4

[0072] The only difference between this embodiment and embodiment 1 is that the concentration of the intercalating agent (glucose) in the mixed solution is 0.1 g / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0073] Example 5

[0074] The only difference between this embodiment and embodiment 1 is that the concentration of the intercalating agent (glucose) in the mixed solution is 3 g / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0075] Example 6

[0076] The only difference between this embodiment and embodiment 1 is that the concentration of glucose in the detergent in step (3) is 0.01 g / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0077] Example 7

[0078] The only difference between this embodiment and embodiment 1 is that the concentration of glucose in the detergent in step (3) is 2 g / L, and the other conditions and parameters are exactly the same as those in embodiment 1.

[0079] Comparative Example 1

[0080] The only difference between this comparative example and Example 1 is that glucose is not added in step (1), and the other conditions and parameters are exactly the same as those in Example 1.

[0081] The SEM image of the prepared cobalt hydroxide is shown in FIG4 .

[0082] Comparative Example 2

[0083] The only difference between this comparative example and Example 1 is that the detergent used in step (3) is deionized water, and the other conditions and parameters are exactly the same as those in Example 1.

[0084] The SEM image of the prepared cobalt hydroxide is shown in FIG5 .

[0085] Comparative Example 3

[0086] The only difference between this comparative example and Example 1 is that glucose is injected into the bottom liquid in the form of a solution, cobalt salt solution and liquid alkali, and other conditions and parameters are exactly the same as those in Example 1.

[0087] Performance testing:

[0088] 50 kg of the cobalt hydroxide prepared in the embodiment and the comparative example was mixed with one equivalent of lithium carbonate in a three-dimensional mixer for 30 min. The mixed material was placed in a box furnace for sintering at a sintering temperature of 800 degrees and a sintering time of 10 h. After sintering, it was naturally cooled and sieved with a 300-mesh sieve to obtain lithium cobalt oxide. The sintered lithium cobalt oxide material was used as the positive electrode and the lithium sheet as the negative electrode to assemble a button battery. The first week charge and discharge capacity was tested at a current density of 0.1C on a blue electric test cabinet, and the capacity retention rate at a current density of 1C was tested. The test results are shown in Table 1:

[0089] Table 1

[0090] As can be seen from Table 1, from Examples 1-3, the first-week discharge specific capacity of the lithium cobalt oxide battery made using the α-cobalt hydroxide disclosed in the present disclosure can reach more than 194.9 mAh / g, and the 25-cycle capacity retention rate at 1C can reach more than 87.2%.

[0091] By comparison of Example 1 and Examples 4-5, it can be seen that in the preparation process of α-cobalt hydroxide described in the present disclosure, the concentration of the interlayer intercalant in the mixed solution affects its structure and thus affects its performance. The concentration of the interlayer intercalant in the mixed solution is controlled at 0.5-2 g / L, and the α-cobalt hydroxide obtained has an excellent structure and good performance. If the concentration of the interlayer intercalant in the mixed solution is too high, it will have little effect on the electrochemical properties of the product, but it will cause the organic matter concentration in the reaction system to be too high, increase the wastewater treatment cost, and cause waste of raw materials. If the concentration of the interlayer intercalant in the mixed solution is too low, it will lead to incomplete intercalation, deviation in the interlayer spacing, and reduced product performance.

[0092] By comparison of Example 1 and Examples 6-7, it can be seen that in the preparation process of α-cobalt hydroxide described in the present disclosure, the concentration of the interlayer intercalant in the detergent will affect its structure and thus affect its performance. The concentration of the interlayer intercalant in the detergent is controlled at 0.05 to 1 g / L, and the α-cobalt hydroxide obtained has an excellent structure and good performance. If the concentration of the interlayer intercalant in the detergent is too high, it will have little effect on the electrochemical properties of the product, but will cause the concentration of organic matter in the washing wastewater to be too high, increase the wastewater treatment cost, and cause waste of raw materials. If the concentration of the interlayer intercalant in the detergent is too low, some materials will not be able to stably maintain the α-cobalt hydroxide structure, and will be converted into β-cobalt hydroxide during the washing process, thereby affecting product performance.

[0093] By comparison between Example 1 and Comparative Example 1, it can be seen that the present disclosure uses liquid alkali and cobalt metal liquid for precipitation, and adds an interlayer intercalant to the cobalt salt solution to form a sheet-intercalated spherical morphology of cobalt hydroxide. The diameter of the interlayer intercalant is about 0.3 nm, and it can be used as an interlayer intercalant to be intercalated between the uncollapsed α-cobalt hydroxide layers. The hydroxyl groups on both sides of the interlayer intercalant can form hydrogen bonds with the hydroxyl groups of the cobalt hydroxide, making the α-cobalt hydroxide structure more stable, thereby obtaining a spherical α-cobalt hydroxide with intact crystallinity and tightly intercalated primary particles.

[0094] From the comparison between Example 1 and Comparative Example 2, it can be seen that the use of a detergent containing an intercalating agent can not only prevent the oxidation of cobalt hydroxide, but also further maintain the stability of α-cobalt hydroxide, thereby fundamentally inhibiting the phase transformation of α-cobalt hydroxide.

[0095] From the comparison between Example 1 and Comparative Example 3, it can be seen that the electrochemical performance of the present disclosure is significantly better than that of the separate liquid feeding method when the cobalt salt and the interlayer intercalator are mixed in advance to form a mixed solution. This is mainly because the uniformity of the intercalator in the reaction system cannot be guaranteed when the liquid is fed separately, resulting in a significant decrease in the effect of the interlayer intercalator and reduced product performance.

[0096] The SEM images of cobalt hydroxide obtained in Example 1-3 and Comparative Example 1-2 are shown in Figure 1-5, and the XRD comparison diagram of cobalt hydroxide obtained in Example 1-3 and Comparative Example 1-2 is shown in Figure 6. It can be seen from Figure 1-3 that as the glucose concentration increases, the spherical particles are more tightly intercalated. Combined with Figure 6, it can be seen that Examples 1-3 of the present disclosure are all high-purity α-cobalt hydroxides with narrow half-peak widths and high peak intensities, indicating that the present disclosure can obtain spherical α-cobalt hydroxides with good crystallinity and relatively tight primary particle intercalation by adding an interlayer intercalator. By comparing Figures 1-3 with Figures 4-5 and Figure 6, it can be seen that glucose is not used in the liquid feeding process of Comparative Example 1. It can be seen from the SEM that when glucose is not used, the spherical particles are very loosely intercalated. No glucose is added during the washing process of Comparative Example 2, and a large number of newly generated primary particles are present on the surface of the sample, indicating that the structure will be reorganized when glucose is not contained in the washing water, and it will be converted from α-cobalt hydroxide to β-cobalt hydroxide.

Claims

1. A method for preparing α-cobalt hydroxide, The following steps are involved: (1) mixing a cobalt salt, an interlayer intercalation agent and a solvent to obtain a mixed solution; (2) injecting the mixed solution and liquid caustic soda into the bottom liquid in parallel to carry out a coprecipitation reaction to obtain a cobalt hydroxide slurry; (3) The cobalt hydroxide slurry is separated into solid and liquid, washed with a detergent containing an intercalation agent, and dried to obtain the α-cobalt hydroxide.

2. The preparation method according to claim 1, in, The cobalt salt in step (1) includes any one of cobalt chloride, cobalt sulfate or cobalt nitrate, or a combination of at least two of them.

3. The preparation method according to claim 1 or 2, in, The intercalator includes glucose.

4. The preparation method according to any one of claims 1 to 3, in, The concentration of the cobalt salt in the mixed solution of step (1) is 90-130 g / L.

5. The preparation method according to any one of claims 1 to 4, in, The concentration of the intercalation agent in the mixed solution of step (1) is 0.5-2 g / L.

6. The preparation method according to any one of claims 1 to 5, in, The base liquid in step (2) comprises sodium hydroxide.

7. The preparation method according to any one of claims 1 to 6, in, The pH of the base solution in step (2) is 9.5 to 10.

5.

8. The preparation method according to any one of claims 1 to 7, in, The temperature of the base liquid in step (2) is 40-50°C.

9. The preparation method according to any one of claims 1 to 8, in, The stirring speed of the coprecipitation reaction in step (2) is 200 to 500 rpm.

10. The preparation method according to any one of claims 1 to 9, in, The atmosphere of the coprecipitation reaction in step (2) comprises nitrogen; Optionally, the flow rate of the nitrogen is 10 to 20 L / min.

11. The preparation method according to any one of claims 1 to 10, in, The pH of the coprecipitation reaction in step (2) is 8 to 9; Optionally, the endpoint of the coprecipitation reaction is that the particle size of particles in the system is 5 to 22 μm.

12. The preparation method according to any one of claims 1 to 11, in, The concentration of the intercalating agent in the detergent in step (3) is 0.05-1 g / L; Optionally, the volume ratio of the detergent to the cobalt hydroxide slurry is (0.5-1.5):

1.

13. The preparation method according to any one of claims 1 to 12, in, The drying equipment in step (3) includes any one of a vacuum oven, a nitrogen furnace or a muffle furnace, or a combination of at least two thereof; Optionally, the drying temperature is 100-120°C; Optionally, the drying time is 16 to 20 hours; Optionally, sieving is performed after drying; Optionally, the mesh size of the sieving sieve is 200 to 400 meshes.

14. α-Cobalt hydroxide prepared by the method according to any one of claims 1 to 13.

15. Lithium cobalt oxide prepared by mixing and sintering the α-cobalt hydroxide as claimed in claim 14 and a lithium source.

16. A lithium ion battery comprising the lithium cobalt oxide according to claim 15.

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