Method for regulating and controlling morphology of cobaltosic oxide and application thereof

Abstract

The invention provides a method for regulating and controlling the morphology of cobaltosic oxide and application thereof, and the method comprises the following steps: carrying out first mixing and reaction on a cobalt salt solution and an ammonium bicarbonate substance solution to obtain cobalt carbonate containing ammonium chloride; cobalt salt in the cobalt salt solution comprises chlorine-containing cobalt salt or chlorine-free cobalt salt, and when the cobalt salt in the cobalt salt solution is chlorine-free cobalt salt, ammonium chloride is also added during the first mixing; and carrying out secondary mixing and calcining on a macromolecular additive and the cobalt carbonate containing ammonium chloride to obtain the cobaltosic oxide with controllable morphology. According to the method, by introducing the additive, the additive adsorbs a specific crystal face and controls the crystal face growth of the cobaltosic oxide, so that the morphology of the cobaltosic oxide is accurately regulated and controlled, the dominant growth crystal face of the cobaltosic oxide can be controlled, the lithium matching sintering activity of the cobaltosic oxide during preparation of the lithium cobalt oxide is improved, and the preparation process is simple. Therefore, the performance of the lithium cobalt oxide material is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of lithium battery positive electrode materials and relates to a method for regulating the morphology of cobalt tetroxide and an application thereof. Background Art

[0002] As 3C battery products tend to be "lighter, thinner and more durable", higher requirements are placed on the performance of lithium-ion batteries, and they are now mainly developing in the direction of high energy density, high voltage, high compaction and high rate. Among them, lithium cobalt oxide positive electrode materials have the advantages of large specific capacity, high voltage and good cycle performance, and have been widely used in 3C battery products. Cobalt oxide is the main raw material for the preparation of lithium cobalt oxide, which will affect the performance of lithium cobalt oxide materials, especially the particle morphology of cobalt oxide will have a great influence on the activity of lithium cobalt oxide.

[0003] Based on the above research, it is necessary to provide a preparation method for regulating the morphology of cobalt tetroxide, so as to achieve the purpose of being able to accurately regulate the morphology of cobalt tetroxide, so as to controllably obtain cobalt tetroxide with different morphologies according to different needs. Summary of the invention

[0004] The object of the present invention is to provide a method for regulating the morphology of cobalt tetroxide and its application. The method introduces an additive so that the additive adsorbs a specific crystal plane and controls the crystal plane growth of cobalt tetroxide, thereby accurately regulating the morphology of cobalt tetroxide, and can also control the dominant growth crystal plane of cobalt tetroxide, thereby improving the lithium sintering activity of cobalt tetroxide when preparing lithium cobaltate, thereby further improving the performance of lithium cobaltate materials.

[0005] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a method for regulating the morphology of cobalt tetroxide, the method comprising the following steps:

[0007] (1) mixing and reacting a cobalt salt solution and an ammonium carbonate solution to obtain cobalt carbonate containing ammonium chloride;

[0008] The cobalt salt in the cobalt salt solution includes a chlorine-containing cobalt salt or a chlorine-free cobalt salt. When the cobalt salt in the cobalt salt solution is a chlorine-free cobalt salt, ammonium chloride is also added during the first mixing;

[0009] (2) The polymer additive and the cobalt carbonate containing ammonium chloride described in step (1) are mixed and calcined for a second time to obtain cobalt tetroxide with controllable morphology.

[0010] During the growth process, the growth of cobalt tetroxide on the (100) and (111) crystal planes is more obvious. When the diffraction peak intensity ratio (R) of these two crystal planes is different, cobalt tetroxide will show different morphologies. When R = I (100) / I (111) = 0.58, cobalt tetroxide is a cube; when R = I (100) / I (111) = 1.73, cobalt tetroxide is a standard octahedron, such as Figure 1 As shown, when R has different values, cobalt tetroxide has different morphologies.

[0011] Therefore, according to the influence of the I(100) / I(111) intensity ratio on the morphology of cobalt tetroxide, the present invention introduces ammonium chloride and polymer additives into the preparation process of cobalt tetroxide, wherein the ammonium chloride has the function of adsorbing the (111) crystal plane, resulting in that the growth rate of the (100) crystal plane is greater than that of the (111), so that the morphology of cobalt tetroxide presents an octahedron; and the polymer additive can adsorb the (100) crystal plane, resulting in that the growth rate of the (100) crystal plane is less than that of the (111), so that the morphology of cobalt tetroxide presents a cube or a sphere. Therefore, the present invention can make different crystal planes present different growth rates according to different addition ratios of ammonium chloride and the polymer additive, so that the diffraction intensity of the (100) crystal plane and the (111) crystal plane changes, thereby being able to control the diffraction peak intensity ratio R of the two crystal planes (100) and (111). As mentioned above, the R value affects the morphology of cobalt tetroxide. Therefore, by using different addition ratios of ammonium chloride and the polymer additive, the morphology of cobalt tetroxide can be controlled, thereby obtaining cobalt tetroxide with controllable morphology.

[0012] The cobalt salt of the present invention includes a chlorine-containing cobalt salt or a chlorine-free cobalt salt. When the cobalt salt is a chlorine-containing cobalt salt, the chlorine-containing cobalt salt reacts with an ammonium carbonate substance to obtain ammonium chloride and cobalt carbonate. Therefore, there is no need to add additional ammonium chloride during the first mixing, thereby reducing the cost. When the cobalt salt is a chlorine-free cobalt salt, ammonium chloride needs to be added additionally during the mixing to ensure that cobalt carbonate containing ammonium chloride is obtained.

[0013] Preferably, the cobalt carbonate containing ammonium chloride in step (1) is also washed with water before step (2).

[0014] The ammonium chloride-containing cobalt carbonate obtained by the present invention can be washed with water to control the content of ammonium chloride, or can be left without water washing to retain more ammonium chloride.

[0015] Preferably, during the water washing, the mass ratio of pure water to cobalt carbonate containing ammonium chloride is less than 10, for example, it can be 9.5, 8.5, 7.5, 6.5, 5.5, 4.5, 3.5, 2.5, 1.5 or 0.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] The purpose of washing the cobalt carbonate containing ammonium chloride with water is to wash away the ammonium chloride and control the content of the ammonium chloride. If too much pure water is used during the water washing, the ammonium chloride will be basically washed away, so that the ammonium chloride cannot effectively play the role of regulating the growth of the cobalt tetroxide crystal surface. In order to ensure that the ammonium chloride that can effectively play a role still exists in the cobalt carbonate, the mass ratio of pure water to the cobalt carbonate containing ammonium chloride is controlled to be less than 10.

[0017] Preferably, the water washing temperature is 60°C-80°C, for example, 60°C, 70°C or 80°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the reaction temperature in step (1) is 35-50°C, for example, 35°C, 40°C, 45°C or 50°C, and the reaction time is 35-45h, for example, 35h, 40h or 45h, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the pH of the reaction in step (1) is 7-7.5, for example, 7, 7.2 or 7.5, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, the particle size Dv50 of the cobalt carbonate containing ammonium chloride in step (1) is 3 μm-4 μm, for example, 3 μm, 3.2 μm, 3.4 μm, 3.6 μm, 3.8 μm or 4 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the ammonium carbonate material comprises ammonium bicarbonate.

[0022] The carbon ammonium material of the present invention can be ammonium carbonate or ammonium bicarbonate, preferably ammonium bicarbonate, so as to ensure the yield of cobalt carbonate.

[0023] Preferably, the cobalt salt in the cobalt salt solution in step (1) comprises cobalt chloride and / or cobalt sulfate.

[0024] Preferably, the mass of the polymer additive in step (2) is 0.01wt%-0.1wt% of the mass of the cobalt carbonate containing ammonium chloride in step (1), for example, it can be 0.01wt%, 0.03wt%, 0.05wt%, 0.07wt%, 0.09wt% or 0.1wt%, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 0.01wt%-0.05wt%.

[0025] The addition amount of the polymer additive of the present invention will affect the growth of cobalt tetroxide. If the addition amount of the polymer additive is too much compared to the mass of cobalt carbonate containing ammonium chloride, it will affect the dispersion of cobalt carbonate containing ammonium chloride, making it difficult to evenly disperse the cobalt carbonate containing ammonium chloride, which will cause cobalt tetroxide particles to agglomerate. If the addition amount of the polymer additive is too little compared to the mass of cobalt carbonate containing ammonium chloride, the effect of the polymer additive on controlling the growth of the crystal face will decrease, affecting the regulation of the morphology of cobalt tetroxide, affecting the dominant growth crystal face, and affecting the performance of lithium cobalt oxide.

[0026] Preferably, the polymer additive in step (2) includes any one of PVA (polyvinyl alcohol), CTAB (cetyltrimethylammonium bromide), PEG (polyethylene glycol) or PVDF (polyvinylidene fluoride), or a combination of at least two of them.

[0027] The type of polymer additive selected in the present invention will also affect the morphology of cobalt tetroxide. Different polymer additives will cause different growth energies of the crystal surface when adsorbed on the crystal surface. Different growth energies will cause different growth rates of the crystal surface. When the crystal surface growth energy is larger, the crystal surface growth rate is faster. Therefore, when the morphology of cobalt tetroxide is adjusted together with ammonium chloride, when different types of polymer additives are selected, the growth rates of the adsorbed crystal surfaces of the polymer additives are different. When used together with ammonium chloride, the morphology of cobalt tetroxide will also be affected.

[0028] Preferably, the calcination temperature in step (2) is 720°C-800°C, for example, 720°C, 740°C, 760°C, 780°C or 800°C, and the calcination time is 4h-6h, for example, 4h, 5h or 6h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] Preferably, the morphology of the cobalt tetroxide in step (2) includes any one of an octahedron, a prismatic octahedron or a cube.

[0030] In a second aspect, the present invention provides an application of cobalt trioxide prepared by the method described in the first aspect, wherein the application includes use in preparing lithium cobalt oxide positive electrode materials.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The invention introduces ammonium chloride and a polymer additive in the process of preparing cobalt tetroxide, utilizes the function of ammonium chloride to adsorb (111) crystal planes, and utilizes the function of the polymer additive to adsorb (100) crystal planes. When the ratio of ammonium chloride to the polymer additive is different, the growth of the cobalt tetroxide crystal planes is affected, the diffraction intensity of the crystal planes is affected, and thus the R value is affected, and finally the morphology of the cobalt tetroxide is affected. At the same time, the obtained cobalt tetroxide has multiple adjustable morphologies and can present different advantageous growth crystal planes. In addition, the invention can also adjust the advantageous growth crystal planes of cobalt tetroxide according to the needs of preparing positive electrode materials, improve the lithium sintering activity of cobalt tetroxide in preparing lithium cobaltate, and thus improve the performance of lithium cobaltate positive electrode materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of the morphology of cobalt trioxide according to the present invention;

[0034] Figure 2 This is a morphology of cobalt tetroxide prepared in Example 1;

[0035] Figure 3 This is a morphology of cobalt tetroxide prepared in Example 2;

[0036] Figure 4 This is a morphology image of cobalt tetroxide prepared in Example 3;

[0037] Figure 5 This is a morphology of cobalt tetroxide prepared in Comparative Example 1;

[0038] Figure 6 The XRD diagrams of the cobalt tetroxide prepared in Examples 1-3 of the present invention and Comparative Example 1, as well as standard cobalt tetroxide. DETAILED DESCRIPTION

[0039] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0040] Example 1

[0041] This embodiment provides a method for regulating the morphology of cobalt trioxide, the method comprising the following steps:

[0042] (1) A cobalt chloride solution and an ammonium bicarbonate solution with a concentration of 130 g / L, respectively, were introduced into a reaction kettle for mixing, and a coprecipitation reaction was carried out at a temperature of 37° C. and a pH of 7.2 for 40 h, wherein the flow rate of the cobalt chloride solution was 500 L / h, and the pH of the reaction was controlled by controlling the flow rate of the ammonium bicarbonate solution to obtain ammonium chloride-containing cobalt carbonate with a Dv50 of 3 μm, and the ammonium chloride-containing cobalt carbonate was washed with hot pure water at 60° C., and the amount of pure water was 4 m / t of cobalt carbonate. 3 The washing is carried out with pure water, that is, the mass ratio of the pure water used in the washing to the cobalt carbonate containing ammonium chloride is 4;

[0043] (2) drying the cobalt carbonate and mixing it with PVA, wherein the PVA is 0.01 wt % of the weight of the cobalt carbonate, and then calcining it in a rotary kiln at 750° C. for 4 h to obtain cobalt tetroxide;

[0044] The morphology of the cobalt tetraoxide prepared in this example is as follows Figure 2 As shown, the XRD pattern is Figure 6 shown.

[0045] Example 2

[0046] This embodiment provides a method for regulating the morphology of cobalt tetroxide, the method comprising the following steps:

[0047] (1) A cobalt chloride solution and an ammonium bicarbonate solution with a concentration of 130 g / L, respectively, were introduced into a reaction kettle for mixing, and a coprecipitation reaction was carried out at a temperature of 40° C. and a pH of 7.0 for 45 hours, wherein the flow rate of the cobalt chloride solution was 500 L / h, and the pH of the reaction was controlled by controlling the flow rate of the ammonium bicarbonate solution, to obtain ammonium chloride-containing cobalt carbonate with a Dv50 of 4 μm, and the cobalt carbonate was washed with hot pure water at 80° C., and the amount of washing water was 4 m / s for 1 t of cobalt carbonate. 3 The washing is carried out with water, that is, the mass ratio of pure water to cobalt carbonate containing ammonium chloride used in the washing is 4;

[0048] (2) drying the cobalt carbonate and mixing it with PEG, wherein the PEG is 0.05 wt % of the weight of the cobalt carbonate, and then calcining it in a rotary kiln at 800° C. for 4 h to obtain cobalt tetroxide;

[0049] The morphology of the cobalt tetraoxide prepared in this example is as follows Figure 3 As shown, the XRD pattern is Figure 6 shown.

[0050] Example 3

[0051] This embodiment provides a method for regulating the morphology of cobalt trioxide, the method comprising the following steps:

[0052] (1) A cobalt chloride solution and an ammonium bicarbonate solution with a concentration of 130 g / L were introduced into a reactor and mixed, and a coprecipitation reaction was carried out at a temperature of 50° C. and a pH of 7.5 for 35 hours, wherein the flow rate of the cobalt chloride solution was 500 L / h, and the pH of the reaction was controlled by controlling the flow rate of the ammonium bicarbonate solution to obtain ammonium chloride-containing cobalt carbonate with a Dv50 of 3.5 μm, and the cobalt carbonate was washed with hot pure water at 60° C., and the washing water volume was 4 m / s for 1 t of cobalt carbonate. 3 The washing is carried out with water, that is, the mass ratio of water to cobalt carbonate containing ammonium chloride used in the washing is 4;

[0053] (2) drying the cobalt carbonate and mixing it with CTAB, wherein the CTAB is 0.02 wt % of the weight of the cobalt carbonate, and then calcining it in a rotary kiln at 750° C. for 4 h to obtain cobalt tetroxide;

[0054] The morphology of the cobalt tetraoxide prepared in this example is as follows Figure 4 As shown, the XRD pattern is Figure 6 shown.

[0055] Example 4

[0056] This embodiment provides a method for regulating the morphology of cobalt tetroxide, which is the same as that of embodiment 1 except that the 130 g / L cobalt chloride solution in step (1) is replaced by a mixed solution containing 130 g / L cobalt sulfate and 130 g / L ammonium chloride.

[0057] Example 5

[0058] This embodiment provides a method for regulating the morphology of cobalt tetroxide. The method is the same as that of Embodiment 1, except that the cobalt carbonate containing ammonium chloride obtained in step (1) is not washed with water.

[0059] Example 6

[0060] This embodiment provides a method for regulating the morphology of cobalt trioxide. In the method, except that the amount of washing water in step (1) is 9 m3 / t of cobalt carbonate, 3 The above steps are the same as those of Example 1 except that the washing is performed with water, that is, the mass ratio of water to cobalt carbonate containing ammonium chloride used in the washing is 9.

[0061] Example 7

[0062] This embodiment provides a method for regulating the morphology of cobalt tetroxide, which is the same as that of embodiment 1 except that in step (2), the PVA is 0.005 wt % of the weight of cobalt carbonate.

[0063] Example 8

[0064] This embodiment provides a method for regulating the morphology of cobalt tetroxide, which is the same as that of embodiment 1 except that in step (2), the PVA is 0.1 wt % of the weight of cobalt carbonate.

[0065] Example 9

[0066] This embodiment provides a method for regulating the morphology of cobalt tetroxide. The method is the same as that of embodiment 1 except that in step (2), the PVA is 0.2 wt % of the weight of cobalt carbonate.

[0067] Comparative Example 1

[0068] This comparative example provides a method for regulating the morphology of cobalt trioxide. In the method, the cobalt carbonate described in step (1) does not contain ammonium chloride, wherein the amount of washing water is 10 m3 / t of cobalt carbonate. 3 The washing is carried out with water, that is, the mass ratio of water to cobalt carbonate containing ammonium chloride used in the washing is 10, and the rest is the same as in Example 1;

[0069] The morphology of the cobalt tetraoxide prepared in this comparative example is as follows Figure 5 As shown, the XRD pattern is Figure 6 shown.

[0070] Comparative Example 2

[0071] This comparative example provides a method for regulating the morphology of cobalt trioxide. In the method, the cobalt carbonate described in step (1) does not contain ammonium chloride, wherein the amount of washing water is 10 m3 / t of cobalt carbonate. 3 The method is the same as that of Example 1 except that the water is washed with water, that is, the mass ratio of water to cobalt carbonate containing ammonium chloride is 10, and PVA is not added in step (2).

[0072] Comparative Example 3

[0073] This comparative example provides a method for regulating the morphology of cobalt tetroxide. The method is the same as Example 1 except that PVA is not added in step (2).

[0074] The cobalt trioxide obtained in the above embodiments and comparative examples was sintered with a lithium source according to a molar ratio of Li:Co=1.05 to prepare lithium cobalt oxide, and then lithium cobalt oxide, acetylene black and PVDF were mixed according to a weight ratio of 8:1:1, and N-methylpyrrolidone was used as a solvent to prepare a positive electrode slurry; by mass percentage, 94.5wt% of graphite, 2wt% of acetylene black, 1.5wt% of sodium carboxymethyl cellulose, 2wt% of styrene-butadiene rubber and water were mixed to prepare a negative electrode slurry, and glass fiber was used as a diaphragm and lithium hexafluorophosphate was used as an electrolyte to prepare a button battery for electrochemical performance testing. The conditions of the electrochemical performance test were within the charge and discharge voltage range of 2.3-4.5V, and 45 cycles were performed at a rate of 0.1C. The test results are shown in Table 1:

[0075] Table 1

[0076]

[0077]

[0078] From Table 1 we can see that:

[0079] (1) Combining Examples 1-3 with Comparative Examples 1 and 3, Figure 2-5 It can be seen that the morphologies of Examples 1-3 and Comparative Examples 1 and 3 are octahedron, prismatic octahedron, cube, spherical and octahedron, respectively. Therefore, the embodiments of the present invention can adjust the morphology of cobalt oxide by adding ammonium chloride and polymer additives, and can also improve the electrochemical properties of lithium cobalt oxide materials. In addition, by Figure 6 It can be seen from the XRD diagram that the diffraction pattern of the cobalt oxide obtained in the present invention corresponds to the diffraction peak of the standard cobalt oxide; from Example 1 and Comparative Example 2, it can be seen that Comparative Example 2 does not add any additives for regulating the morphology of cobalt oxide, and the specific capacity and cycle performance of the obtained lithium cobalt oxide material are lower than those in Example 1.

[0080] (2) It can be seen from Examples 1 and 4 that the cobalt salt of Example 4 of the present invention can be a chlorine-free cobalt salt, but ammonium chloride needs to be added additionally. Therefore, compared with Example 1, it will not only increase the preparation cost, but also affect the electrochemical properties of the lithium cobalt oxide material; It can be seen from Examples 1 and 5-6 that the present invention can use different amounts of pure water for washing, or no water washing, so that cobalt carbonate contains different amounts of ammonium chloride to obtain cobalt tetroxide with a specific morphology. At the same time, an appropriate amount of water washing helps to promote the growth of the dominant growth crystal face and improve the electrochemical properties of the lithium cobalt oxide material; It can be seen from Examples 1, 2 and 7-9 that the content of the polymer additive of the present invention affects the performance of lithium cobalt oxide, wherein the content of the suitable polymer additive, such as preferably 0.01wt%-0.05wt%, helps to promote the growth of the dominant growth crystal face and avoid the agglomeration of cobalt tetroxide, thereby improving the electrochemical properties of lithium cobalt oxide.

[0081] In summary, the present invention provides a method for regulating the morphology of cobalt tetroxide and its application. The method introduces an additive so that the additive adsorbs a specific crystal plane and controls the crystal plane growth of cobalt tetroxide, thereby accurately regulating the morphology of cobalt tetroxide, and can also control the dominant growth crystal plane of cobalt tetroxide, thereby improving the lithium sintering activity of cobalt tetroxide when preparing lithium cobaltate, thereby further improving the performance of lithium cobaltate materials.

[0082] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A method for regulating the morphology of cobalt trioxide, characterized in that: The method comprises the following steps: (1) mixing and reacting a cobalt salt solution and an ammonium carbonate solution to obtain cobalt carbonate containing ammonium chloride; The cobalt salt in the cobalt salt solution includes a chlorine-containing cobalt salt or a chlorine-free cobalt salt. When the cobalt salt in the cobalt salt solution is a chlorine-free cobalt salt, ammonium chloride is also added during the first mixing; (2) The polymer additive and the cobalt carbonate containing ammonium chloride described in step (1) are mixed and calcined for a second time to obtain cobalt tetroxide with controllable morphology.

2. The method according to claim 1, characterized in that The cobalt carbonate containing ammonium chloride in step (1) is also washed with water before step (2).

3. The method according to claim 2, characterized in that During the water washing, the mass ratio of pure water to cobalt carbonate containing ammonium chloride is less than 10; Preferably, the water washing temperature is 60°C-80°C.

4. The method according to any one of claims 1 to 3, characterized in that: The reaction temperature in step (1) is 35-50°C and the reaction time is 35-45h; Preferably, the pH of the reaction in step (1) is 7-7.5; Preferably, the particle size Dv50 of the cobalt carbonate containing ammonium chloride in step (1) is 3 μm-4 μm.

5. The method according to any one of claims 1 to 4, characterized in that: The ammonium carbonate substance includes ammonium bicarbonate; Preferably, the cobalt salt in the cobalt salt solution in step (1) comprises cobalt chloride and / or cobalt sulfate.

6. The method according to any one of claims 1 to 5, characterized in that: The mass of the polymer additive in step (2) is 0.01wt%-0.1wt% of the mass of the cobalt carbonate containing ammonium chloride in step (1), preferably 0.01wt%-0.05wt%.

7. The method according to any one of claims 1 to 6, characterized in that: The polymer additive in step (2) includes any one of PVA, CTAB, PEG or PVDF, or a combination of at least two of them.

8. The method according to any one of claims 1 to 7, characterized in that: The calcination temperature in step (2) is 720°C-800°C, and the calcination time is 4h-6h.

9. The method according to any one of claims 1 to 8, characterized in that: The morphology of the cobalt tetroxide in step (2) includes any one of an octahedron, a prismatic octahedron, a spheroid or a cube.

10. Use of cobalt trioxide obtained by the method according to any one of claims 1 to 9, characterized in that: The application includes use in preparing lithium cobalt oxide positive electrode materials.

Images