Aluminum-doped cobaltite and preparation method and application thereof
By adding yttrium oxide to the aluminum-doped cobalt tetroxide intermediate and calcining it, the problem of uncontrollable specific surface area of cobalt tetroxide was solved, and cathode materials suitable for different performance requirements were prepared, improving the electrochemical performance and tap density of the battery.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- GEM JIANGSU COBALT IND CO LTD
- Filing Date
- 2023-11-22
- Publication Date
- 2026-06-23
Smart Images
Figure BDA0004563105730000081 
Figure BDA0004563105730000091
Abstract
Description
Technical Field
[0001] This invention belongs to the field of battery cathode material preparation technology, specifically relating to an aluminum-doped cobalt tetroxide, its preparation method, and its application. Background Technology
[0002] Lithium cobalt oxide, as a cathode material, possesses excellent cycle performance, high specific capacity, stable charge-discharge structure, and high operating voltage, making it widely used in the manufacturing of portable electronic products. Lithium cobalt oxide is synthesized from cobalt tetroxide and lithium carbonate. The specific surface area, tap density, and microstructure of cobalt tetroxide significantly influence the final quality of lithium cobalt oxide. Under the same conditions, cobalt tetroxide with a larger specific surface area allows for more thorough contact with lithium carbonate, resulting in a larger reaction area between the cathode material and the electrolyte, better conductivity, and improved rate capability (faster charge-discharge speed). However, excessively large specific surface area of cobalt tetroxide leads to low tap density, affecting the battery's unit capacity and deteriorating cycle and storage performance. Therefore, preparing cobalt tetroxide with a suitable specific surface area is beneficial for improving the electrochemical performance of cathode materials. Different cathode materials require different specific surface areas of cobalt tetroxide; obtaining cobalt tetroxide with the required specific surface area is of great significance for both cathode materials and batteries. Summary of the Invention
[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art, such as the uncontrollable specific surface area of cobalt tetroxide, and thus provide an aluminum-doped cobalt tetroxide, its preparation method and application.
[0004] To this end, the present invention provides the following technical solution.
[0005] This invention provides a method for preparing aluminum-doped cobalt tetroxide, comprising: adding yttrium oxide to an aluminum-doped cobalt tetroxide intermediate and calcining it;
[0006] The amount of yttrium oxide added is 0.005-0.035 wt% of the aluminum-doped cobalt tetroxide intermediate.
[0007] Furthermore, the specific surface area B of aluminum-doped cobalt tetroxide is 2 ≤ B < 3 m². 2 When the yttrium oxide content is / g, the doping amount is 0.008wt%-0.012wt%.
[0008] Preferably, the specific surface area B of aluminum-doped cobalt tetroxide is 3 ≤ B < 4 m². 2 When the yttrium oxide content is / g, the doping amount is 0.018wt%-0.022wt%.
[0009] Preferably, the specific surface area B of aluminum-doped cobalt tetroxide is 4 ≤ B < 6 m².2 When the yttrium oxide content is 0.028wt%-0.032wt%, the doping amount is 0.028wt%-0.032wt%.
[0010] Furthermore, the specific surface area B of aluminum-doped cobalt tetroxide is 2 ≤ B < 3 m². 2 When / g, the calcination includes: holding at 120±3℃ for 60±2min, holding at 180±3℃ for 60±2min, holding at 240±3℃ for 60±2min, holding at 300±3℃ for 60±2min, holding at 360±3℃ for 60±2min, holding at 420±3℃ for 60±2min, holding at 600±3℃ for 60±2min, holding at 660±3℃ for 60±2min, and holding at 720±3℃ for 360±2min;
[0011] Preferably, the specific surface area B of aluminum-doped cobalt tetroxide is 3 ≤ B < 4 m². 2 When / g, the calcination includes: holding at 120±3℃ for 70±2min, holding at 210±3℃ for 70±2min, holding at 300±3℃ for 70±2min, holding at 390±3℃ for 70±2min, holding at 480±3℃ for 70±2min, holding at 560±3℃ for 70±2min, holding at 650±3℃ for 70±2min, and holding at 720±3℃ for 360±2min;
[0012] Preferably, the specific surface area B of aluminum-doped cobalt tetroxide is 4 ≤ B < 6 m². 2 When / g, the calcination includes: holding at a temperature of 70±3℃ for 80±2min, holding at a temperature of 170±3℃ for 80±2min, holding at a temperature of 280±3℃ for 80±2min, holding at a temperature of 390±3℃ for 80±2min, holding at a temperature of 500±3℃ for 80±2min, holding at a temperature of 610±3℃ for 80±2min, and holding at a temperature of 720±3℃ for 360±2min.
[0013] Furthermore, during calcination, the aluminum-doped cobalt tetroxide intermediate is directly moved from one temperature zone to the next.
[0014] The preparation method for the aluminum-doped cobalt tetroxide intermediate product includes:
[0015] (1) Prepare a cobalt-aluminum solution;
[0016] (2) Cobalt-aluminum solution and precipitant are added to complexing agent solution at the same time to produce co-precipitation reaction and obtain slurry; when the particle size of slurry reaches 12μm, feeding is stopped and aging is carried out.
[0017] The aging time is 1-2 hours;
[0018] Preferably, during the co-precipitation reaction, the flow rate of the cobalt-aluminum solution added is 23-27 g / min;
[0019] Preferably, the concentration of cobalt ions in the cobalt-aluminum solution is 120-130 g / L;
[0020] Preferably, the concentration of aluminum ions in the cobalt-aluminum solution is 1.0-1.2 g / L.
[0021] The precipitant is ammonia and / or sodium hydroxide;
[0022] Preferably, the pH of the reaction system is 11-12 during the coprecipitation reaction.
[0023] The pH value of the reaction system is controlled by adjusting the amount of precipitant added.
[0024] When preparing a cobalt-aluminum solution, cobalt ions come from cobalt chloride, cobalt sulfate, cobalt nitrate, etc.; aluminum ions come from aluminum chloride, aluminum sulfate, aluminum nitrate, etc.; and the precipitant is ammonia water, sodium hydroxide, etc.
[0025] The complexing agent is at least one of aminotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentacarboxylate, monoethanolamine, and diethanolamine; when preparing the aluminum-doped cobalt tetroxide intermediate, the complexing agent is ensured to be in excess.
[0026] Preferably, the temperature of the coprecipitation reaction is 65-75°C.
[0027] The present invention also provides an aluminum-doped cobalt tetroxide prepared by the above preparation method.
[0028] The present invention also provides a positive electrode material, the raw material of which includes aluminum-doped cobalt tetroxide prepared by the above preparation method.
[0029] The present invention also provides a battery comprising the above-described positive electrode material.
[0030] The technical solution of this invention has the following advantages:
[0031] 1. The present invention provides a method for preparing aluminum-doped cobalt tetroxide, which includes adding yttrium oxide to an intermediate product of aluminum-doped cobalt tetroxide and calcining it; wherein the amount of yttrium oxide added is 0.005-0.035 wt% of the intermediate product of aluminum-doped cobalt tetroxide. The specific surface area of the aluminum-doped cobalt tetroxide prepared by this method can be controlled within a suitable range, making it suitable for cathode materials and batteries with different performance requirements; furthermore, the aluminum-doped cobalt tetroxide prepared by this method has a good tap density, greater than 2.5 g / cm³. 3This invention effectively meets the tap density requirements for small-particle-size aluminum-doped cobalt tetroxide in the battery-grade cobalt tetroxide field. By adding 0.005-0.035 wt% yttrium oxide to the aluminum-doped cobalt tetroxide intermediate and then calcining, a specific surface area of not less than 2 m² can be obtained. 2 / g, less than 6m 2 / g of aluminum-doped cobalt tetroxide; furthermore, the specific surface area of aluminum-doped cobalt tetroxide can be controlled by selecting the amount of yttrium oxide added in the range of 0.005-0.035wt%.
[0032] 2. The method for preparing aluminum-doped cobalt tetroxide provided by the present invention can obtain aluminum-doped cobalt tetroxide with different specific surface areas by controlling the yttrium oxide content; furthermore, the specific surface area of aluminum-doped cobalt tetroxide can be precisely controlled by the amount of yttrium oxide added and the matching calcination process. Detailed Implementation
[0033] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.
[0034] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.
[0035] Example 1
[0036] This embodiment provides a method for preparing aluminum-doped cobalt tetroxide, including the following steps:
[0037] (1) The target specific surface area of aluminum-doped cobalt tetroxide is 2≤B<3m² 2 / g. Using CoCl2·6H2O and aluminum chloride as raw materials, a cobalt-aluminum solution with a cobalt ion concentration of 125 g / L and an aluminum ion concentration of 1.1 g / L was prepared.
[0038] (2) Add pure water to the reactor and add aminotriacetic acid complexing agent to the pure water. The amount of complexing agent added is 125g to ensure that the complexing agent is in excess during the preparation process. Turn on the stirring and turn the speed to 350r / min. Pass compressed air with a flow rate of 6L / min. When the temperature inside the reactor rises to 70℃, start feeding. Add the above cobalt-aluminum solution and ammonia water to the reactor at the same time to carry out co-precipitation reaction to obtain slurry. The flow rate of cobalt-aluminum solution added is 25g / min, and the flow rate of ammonia water added is 11g / min. Control the pH of the co-precipitation reaction to about 10. When the particle size of the slurry reaches 12μm, stop feeding and age in the reactor for 2h. Then, put the slurry into the filter press for pressing. After washing and drying, the aluminum-doped cobalt tetroxide intermediate product is obtained.
[0039] (3) Add 0.01wt% yttrium oxide to the aluminum-doped cobalt tetroxide intermediate product, and place the intermediate product in sequence at 120℃ for 60min, 180℃ for 60min, 240℃ for 60min, 300℃ for 60min, 360℃ for 60min, 420℃ for 60min, 600℃ for 60min, 660℃ for 60min, and 720℃ for 360min to obtain aluminum-doped cobalt tetroxide.
[0040] Example 2
[0041] This embodiment provides a method for preparing aluminum-doped cobalt tetroxide, including the following steps:
[0042] (1) The target specific surface area of aluminum-doped cobalt tetroxide is 3≤B<4m² 2 / g. Using CoCl2·6H2O and aluminum chloride as raw materials, a cobalt-aluminum solution with a cobalt ion concentration of 125 g / L and an aluminum ion concentration of 1.1 g / L was prepared.
[0043] (2) Add pure water to the reactor and add aminotriacetic acid complexing agent to the pure water. The amount of complexing agent added is 125g to ensure that the complexing agent is in excess during the preparation process. Turn on the stirring and turn the speed to 350r / min. Pass compressed air with a flow rate of 6L / min. When the temperature inside the reactor rises to 70℃, start feeding. Add the above cobalt-aluminum solution and ammonia water to the reactor at the same time to carry out co-precipitation reaction to obtain slurry. The flow rate of cobalt-aluminum solution added is 25g / min, and the flow rate of ammonia water added is 11g / min. Control the pH of the co-precipitation reaction to about 10. When the particle size of the slurry reaches 12μm, stop feeding and age in the reactor for 2h. Then, put the slurry into the filter press for pressing. After washing and drying, the aluminum-doped cobalt tetroxide intermediate product is obtained.
[0044] (3) Add 0.02wt% yttrium oxide to the aluminum-doped cobalt tetroxide intermediate, and place it in the following temperatures in sequence: 120℃ for 70 min, 210℃ for 70 min, 300℃ for 70 min, 390℃ for 70 min, 480℃ for 70 min, 560℃ for 70 min, 650℃ for 70 min, and 720℃ for 360 min to obtain aluminum-doped cobalt tetroxide.
[0045] Example 3
[0046] This embodiment provides a method for preparing aluminum-doped cobalt tetroxide, including the following steps:
[0047] (1) The target specific surface area of aluminum-doped cobalt tetroxide is higher than 4≤B<6m². 2 / g. Using CoCl2·6H2O and aluminum chloride as raw materials, a cobalt-aluminum solution with a cobalt ion concentration of 125 g / L and an aluminum ion concentration of 1.1 g / L was prepared.
[0048] (2) Add pure water to the reactor and add aminotriacetic acid complexing agent to the pure water. The amount of complexing agent added is 125g. Start stirring and turn the speed to 350r / min. Pass compressed air with a flow rate of 6L / min. When the temperature inside the reactor rises to 70℃, add the above cobalt-aluminum solution and ammonia water to the reactor at the same time to carry out co-precipitation reaction to obtain slurry. The flow rate of cobalt-aluminum solution added is 25g / min and the flow rate of ammonia water added is 11g / min. Control the pH of the co-precipitation reaction to about 10. When the particle size of the slurry reaches 12μm, stop feeding and age in the reactor for 2h. Then, feed the slurry into a filter press for pressing. After washing and drying, obtain aluminum-doped cobalt tetroxide intermediate product.
[0049] (3) Add 0.03wt% yttrium oxide to the aluminum-doped cobalt tetroxide intermediate product, and place it in the following temperatures in sequence: 70℃ for 80 min, 170℃ for 80 min, 280℃ for 80 min, 390℃ for 80 min, 500℃ for 80 min, 610℃ for 80 min, and 720℃ for 360 min to obtain aluminum-doped cobalt tetroxide.
[0050] Example 4
[0051] This embodiment provides a method for preparing aluminum-doped cobalt tetroxide, including the following steps:
[0052] (1) The target specific surface area of aluminum-doped cobalt tetroxide is 2≤B<3m² 2 / g. Using CoCl2·6H2O and aluminum sulfate as raw materials, a cobalt-aluminum solution with a cobalt ion concentration of 125 g / L and an aluminum ion concentration of 1.1 g / L was prepared.
[0053] (2) Add pure water to the reactor and add monoethanolamine complexing agent to the pure water. The amount of complexing agent added is 125g to ensure that the complexing agent is in excess during the preparation process. Start stirring at 350r / min and introduce compressed air at a flow rate of 6L / min. When the temperature inside the reactor rises to 72℃, start feeding. Add the above cobalt-aluminum solution and ammonia water to the reactor at the same time to carry out co-precipitation reaction to obtain slurry. The flow rate of cobalt-aluminum solution added is 26g / min and the flow rate of sodium hydroxide solution added is 11g / min. Control the pH of the co-precipitation reaction to about 10. Stop feeding when the particle size of the slurry reaches 12μm. Aging in the reactor for 1.5h, and then pump the slurry into the filter press for pressing. After washing and drying, aluminum-doped cobalt tetroxide intermediate product is obtained.
[0054] (3) Add 0.01wt% yttrium oxide to the aluminum-doped cobalt tetroxide intermediate product, and place the intermediate product in sequence at 120℃ for 60min, 180℃ for 60min, 240℃ for 60min, 300℃ for 60min, 360℃ for 60min, 420℃ for 60min, 600℃ for 60min, 660℃ for 60min, and 720℃ for 360min to obtain aluminum-doped cobalt tetroxide.
[0055] Comparative Example 1
[0056] This comparative example provides a method for preparing aluminum-doped cobalt tetroxide. The difference from Example 1 is that step (3) does not add yttrium oxide and is directly calcined.
[0057] Comparative Example 2
[0058] This comparative example provides a method for preparing aluminum-doped cobalt tetroxide. The difference from Example 2 is that step (3) does not add yttrium oxide and is directly calcined.
[0059] Comparative Example 3
[0060] This comparative example provides a method for preparing aluminum-doped cobalt tetroxide. The difference from Example 3 is that step (3) does not add yttrium oxide and is directly calcined.
[0061] Comparative Example 4
[0062] This comparative example provides a method for preparing aluminum-doped cobalt tetroxide, which differs from Example 3 in that the amount of yttrium oxide added in step (3) is 0.06 wt%.
[0063] Test case
[0064] This experimental example provides performance tests of the aluminum-doped cobalt tetroxide prepared in each embodiment and comparative example. The experimental results are as follows: Examples 1-4 were repeated three times each, and the parameters of the aluminum-doped cobalt tetroxide obtained each time were tested; Comparative Examples 1-4 were repeated twice each, and the parameters of the aluminum-doped cobalt tetroxide obtained each time were tested.
[0065] (1) The cobalt content and aluminum doping amount in aluminum-doped cobalt tetroxide were tested, and the results are shown in Table 1. The cobalt content was determined by potentiometric titration, and the aluminum content was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES).
[0066] (2) The specific surface area (BET) of aluminum-doped cobalt tetroxide was tested, and the results are shown in Table 1. The specific surface area was obtained by the BET specific surface area test method.
[0067] (3) The tap density TD of aluminum-doped cobalt tetroxide was tested, and the results are shown in Table 1.
[0068] Table 1. Test results of aluminum-doped cobalt tetroxide in each embodiment and comparative example.
[0069]
[0070]
[0071] Conclusion: The above experimental results demonstrate that adding yttrium oxide and calcining it into the aluminum-doped cobalt tetroxide intermediate can control the specific surface area of the aluminum-doped cobalt tetroxide. Excessive yttrium oxide addition will cause the actual specific surface area of the product to deviate from the target specific surface area. The method of this invention can precisely control the specific surface area of aluminum-doped cobalt tetroxide.
[0072] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.
Claims
1. A method for preparing aluminum-doped cobalt tetroxide, characterized in that, include: Yttrium oxide was added to the aluminum-doped cobalt tetroxide intermediate and then calcined. The specific surface area B of aluminum-doped cobalt tetroxide is 2 ≤ B < 3 m². 2 At / g, the amount of yttrium oxide added is 0.008wt%-0.012wt% of the aluminum-doped cobalt tetroxide intermediate; The specific surface area B of aluminum-doped cobalt tetroxide is 3 ≤ B < 4 m². 2 At / g, the amount of yttrium oxide added is 0.018wt%-0.022wt% of the aluminum-doped cobalt tetroxide intermediate; The specific surface area B of aluminum-doped cobalt tetroxide is 4 ≤ B < 6 m². 2 At / g, the amount of yttrium oxide added is 0.028wt%-0.032wt% of the aluminum-doped cobalt tetroxide intermediate.
2. The preparation method according to claim 1, characterized in that, The specific surface area B of aluminum-doped cobalt tetroxide is 2 ≤ B < 3 m². 2 When / g, the calcination includes: holding at 120±3℃ for 60±2min, holding at 180±3℃ for 60±2min, holding at 240±3℃ for 60±2min, holding at 300±3℃ for 60±2min, holding at 360±3℃ for 60±2min, holding at 420±3℃ for 60±2min, holding at 600±3℃ for 60±2min, holding at 660±3℃ for 60±2min, and holding at 720±3℃ for 360±2min; And / or, the specific surface area B of aluminum-doped cobalt tetroxide is 3 ≤ B < 4 m². 2 When / g, the calcination includes: holding at 120±3℃ for 70±2min, holding at 210±3℃ for 70±2min, holding at 300±3℃ for 70±2min, holding at 390±3℃ for 70±2min, holding at 480±3℃ for 70±2min, holding at 560±3℃ for 70±2min, holding at 650±3℃ for 70±2min, and holding at 720±3℃ for 360±2min; And / or, the specific surface area B of aluminum-doped cobalt tetroxide is 4 ≤ B < 6 m². 2 When / g, the calcination includes: holding at a temperature of 70±3℃ for 80±2min, holding at a temperature of 170±3℃ for 80±2min, holding at a temperature of 280±3℃ for 80±2min, holding at a temperature of 390±3℃ for 80±2min, holding at a temperature of 500±3℃ for 80±2min, holding at a temperature of 610±3℃ for 80±2min, and holding at a temperature of 720±3℃ for 360±2min.
3. The preparation method according to claim 1 or 2, characterized in that, The method for preparing the aluminum-doped cobalt tetroxide intermediate includes: (1) Prepare a cobalt-aluminum solution; (2) Cobalt-aluminum solution and precipitant are added to complexing agent solution at the same time to produce co-precipitation reaction and obtain slurry; when the particle size of slurry reaches 12μm, feeding is stopped and aging is carried out.
4. The preparation method according to claim 3, characterized in that, The aging time is 1-2 hours; And / or, during the co-precipitation reaction, the flow rate of the cobalt-aluminum solution added is 23-27 g / min; And / or, the concentration of cobalt ions in the cobalt-aluminum solution is 120-130 g / L; And / or, the concentration of aluminum ions in the cobalt-aluminum solution is 1.0-1.2 g / L.
5. The preparation method according to claim 3, characterized in that, The precipitant is ammonia and / or sodium hydroxide; And / or, during the coprecipitation reaction, the pH of the reaction system is 11-12.
6. The preparation method according to claim 3, characterized in that, The complexing agent is at least one of aminotriacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentacarboxylate, monoethanolamine, and diethanolamine. And / or, the temperature of the coprecipitation reaction is 65-75°C.