Method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide and application thereof

Abstract

The application provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, which comprises the following steps: firstly, mixing a cobalt source, an aluminum source, a manganese source, a complexing agent and an oxidizing agent in water to obtain a reaction solution; secondly, under the conditions of a certain stirring speed and reaction temperature, adding the reaction solution into a sodium hydroxide solution, controlling the feeding speed and reaction time to obtain a product; and finally, performing solid-liquid separation, washing, drying and crushing treatment on the product to obtain powder-shaped small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide. The preparation method has the advantages of simple reaction conditions, rapidness and fewer harmful components. The aluminum-manganese co-doped hydroxyl cobalt oxide prepared by the application has a small particle size, is beneficial to further sintering and forming, and the two different metal elements of aluminum and manganese can significantly enhance the material structure stability, so that the application has a wide popularization and application prospect in the preparation of lithium ion battery positive electrode materials.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of lithium ion battery cathode materials, and particularly relates to a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide and application thereof. BACKGROUND

[0002] High voltage is one of the main schemes for improving the energy density of nickel-cobalt-manganese ternary batteries. The structure of common ternary cathode materials is easily destroyed at high voltage, lithium ions are difficult to embed, and the cycle life and thermal stability are reduced. At present, the stability of ternary materials at high voltage can be effectively improved by increasing the coating layer and adjusting the electrolyte composition. Hydroxyl cobalt oxide is a good conductive material and has good stability at high voltage. When used as a coating material, it can improve the stability of ternary materials at high voltage and prolong the cycle life while maintaining high capacity.

[0003] The patent with the publication number CN118270854A provides a nano-doped hydroxyl cobalt oxide and a preparation method and application thereof. Aluminum-doped nano hydroxyl cobalt oxide is prepared in a solution by a coprecipitation method, and different cobalt and aluminum ratios in the sample are realized by adjusting the amount of oxidizing agent and aluminum sulfate to control the specific surface area. However, the patent has the following two problems: first, ammonia water is needed in the synthesis process, and the generated wastewater and toxic waste gas need to be treated before being discharged, which increases the cost; second, the reaction time of the method is relatively long (1-4h), which is not conducive to large-scale production.

[0004] The patent with the publication number CN106379948A discloses a method for preparing nano hydroxyl cobalt manganese. The method prepares nano hydroxyl cobalt manganese by uniformly mixing cobalt acetate and manganese acetate in deionized water, passing ozone, centrifuging, washing, and drying. The patent mainly controls the sample morphology and cobalt-manganese ratio by adjusting the solution pH and cobalt-manganese amount. However, the patent has the following two problems: first, a strong oxidizing gas is needed in the synthesis process, which requires high sealing degree of the equipment and has high risk and cost; second, the method also takes a long time, which is not conducive to large-scale production.

[0005] Therefore, a small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide and a preparation method thereof are provided, which are rapid and efficient, energy-saving and environmentally friendly, and conducive to large-scale production. The small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide has important significance for improving the stability of lithium ion battery cathode materials and further improving the electrochemical performance thereof, and is a technical problem to be solved. SUMMARY

[0006] One of the purposes of the application is to provide a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide.

[0007] The second purpose of the application is to provide a small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide with uniformly distributed doping elements.

[0008] The third object of the present application is to provide an application of the aluminum-manganese-doped cobalt oxyhydroxide with small particle size and uniform distribution of doping elements.

[0009] The technical solution adopted by one of the objects of the present application is to provide a method for quickly and efficiently preparing aluminum-manganese-doped cobalt oxyhydroxide with small particle size, which comprises the following steps:

[0010] S1, mixing a cobalt source, an aluminum source, a manganese source, a complexing agent and hydrogen peroxide in water to obtain a reaction solution; in the reaction solution, the weight ratio of metal elements of cobalt, aluminum and manganese is 1000:(1-16):(1-16); the mass concentration of hydrogen peroxide is 20%-30%, and the volume of hydrogen peroxide to the weight of cobalt is 1:(3-8) mL / g;

[0011] S2, under the conditions of a stirring speed of 600-800 rpm and a temperature of 50-75℃, the reaction solution is added to a sodium hydroxide solution, the feeding time is controlled to be 2-3 min, and the reaction time is controlled to be 5-10 min to obtain a product;

[0012] S3, the product is subjected to solid-liquid separation, washing, drying and crushing to obtain a powder of aluminum-manganese-doped cobalt oxyhydroxide with small particle size.

[0013] The general idea of the present application is as follows: in the present application, in order to realize the rapid preparation of cobalt oxyhydroxide with small particle size and uniform distribution of doping elements, the conventional preparation method is improved mainly from two aspects of the selection of oxidizing agent and the optimization and adjustment of feeding mode:

[0014] On the one hand, for the selection of oxidizing agent, the present application uses high-concentration hydrogen peroxide to replace the scheme of using air or other raw materials as the oxidizing agent in the conventional preparation method. The high-concentration hydrogen peroxide has stronger oxidation effect, effectively improves the content and purity of cobalt oxyhydroxide in the material, and reduces the generation of cobalt hydroxide.

[0015] On the other hand, for the setting of feeding mode, the present application prepares a sodium hydroxide solution in advance in the reaction container, and then adds the reaction solution containing cobalt, aluminum and manganese metal elements, a complexing agent and an oxidizing agent into the sodium hydroxide solution. This feeding mode is faster, effectively shortens the feeding time and the reaction time, and is beneficial to obtain a product with smaller particle size.

[0016] Further, in step S1, the cobalt source includes one or more combinations of cobalt chloride, cobalt sulfate and cobalt nitrate; the aluminum source includes aluminum sulfate and / or aluminum chloride; and the manganese source includes one or more combinations of manganese chloride, manganese sulfate and manganese carbonate.

[0017] Further, considering that manganese sulfate introduces sulfate ions, which is not conducive to subsequent water treatment; and manganese carbonate is easy to generate carbon dioxide in an acidic solution, the application preferably uses manganese chloride as the manganese source.

[0018] Further, in step S1, the content of cobalt element in the reaction solution is 80-150 g / L.

[0019] Further, in step S1, citric acid is preferably used as the complexing agent after comparison and screening. In the application, the cobalt-containing reaction solution is an acidic solution, and citric acid can coexist well with ammonia water when directly added to the cobalt solution, and has low danger; compared with EDTA-Na, citric acid has lower price and smaller molecular weight, and is used in smaller amount at the same molar amount.

[0020] Further, in step S1, the addition amount of citric acid is 1%-3% of the weight of cobalt element. When the addition amount is lower than the above range, segregation of aluminum and manganese will occur; and when the addition amount of citric acid is higher than the above range, slow release of cobalt will occur, and other products (such as alpha-cobalt hydroxide and basic cobalt chloride) will be generated, which will affect the purity of the product.

[0021] Preferably, the addition amount of citric acid increases with the increase of the aluminum doping amount. In the application, citric acid is used as the complexing agent to play a slow-release role, reduce the reaction speed of aluminum, cobalt and sodium hydroxide, make the reaction speed of aluminum, cobalt and sodium hydroxide close, reduce segregation, and ensure that aluminum and manganese exist in the form of doping in the final product, rather than in the form of complex.

[0022] Further, in step S2, the weight ratio of sodium hydroxide in the sodium hydroxide solution to cobalt element in the reaction solution is (0.8-1.4):1. Preferably, the concentration of the sodium hydroxide solution is 30%-35%.

[0023] Further, in step S2, the reaction temperature is 60-80℃, and more preferably 65-75℃. If the reaction temperature is too low, the reaction speed will be reduced, the local alkali in the reaction system will be excessive, and the content of cobalt hydroxide will be increased; and if the temperature is too high, the reaction speed will be increased, and the local alkali will be insufficient, which is not conducive to the generation of cobalt hydroxide.

[0024] Further, in step S3, the solid-liquid separation is performed by using a filter press or a centrifuge, and the drying temperature is 80-95℃.

[0025] Further, in step S3, the crushing treatment is performed by grinding and / or a crusher. When the crushing treatment is performed by grinding, the particle size D50 of the product is 2.1-4.2 μm; when the crushing treatment is performed by a crusher, the pressure of an air flow crusher is controlled to be 2-6 MPa, and the frequency is 0.2-1 Hz, and the particle size D50 of the product is 0.2-1 μm. Specifically, the product can be crushed to a desired target particle size range according to the specific application requirements.

[0026] The technical solution for achieving the second purpose of the present application is to provide a small-particle-size aluminum-manganese-doped cobalt oxyhydroxide prepared by the preparation method according to the first purpose of the present application.

[0027] The technical solution for achieving the third purpose of the present application is to provide an application of the small-particle-size aluminum-manganese-doped cobalt oxyhydroxide according to the second purpose of the present application, which is used as a coating material for surface modification of ternary positive electrode material particles.

[0028] Further, the small-particle-size aluminum-manganese-doped cobalt oxyhydroxide provided by the present application can be used for surface coating of high-voltage ternary positive electrode material particles, which can effectively improve the stability of the ternary positive electrode material at high voltage, improve the electrochemical performance thereof, and prolong the cycle life.

[0029] Compared with the prior art, the present application has the following beneficial effects:

[0030] (1) The method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped cobalt oxyhydroxide provided by the present application has simpler reaction conditions and is faster than the solid-phase synthesis method, which can significantly improve the production efficiency, and the synthesized aluminum-manganese co-doped cobalt oxyhydroxide has a smaller particle size, which is beneficial to further sintering and molding. The method provided by the present application also has the advantage of producing less harmful components, which is beneficial to subsequent wastewater and waste gas treatment.

[0031] (2) The small-particle-size aluminum-manganese-doped cobalt oxyhydroxide prepared by the present application has high purity, uniform aluminum and manganese distribution, and small particle size. The simultaneous doping of two different metal elements, aluminum and manganese, can significantly enhance the structural stability of the material. Among them, aluminum can reduce the volume expansion and shrinkage of the electrode material during the cycle process at high voltage, reduce the risk of structural collapse, inhibit the decomposition of the electrolyte at high voltage, and enhance the electrochemical performance of the electrode material; manganese can reduce the crystal distortion of the electrode material during the charge and discharge process, improve the cycle life, improve the thermal stability of the battery, reduce the risk of battery thermal runaway, and thus improve the safety and life of the battery. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A scanning electron microscope image of the small-particle-size aluminum-manganese-doped cobalt oxyhydroxide prepared in Example 1 of the present application;

[0033] Figure 2 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 2 of the present application;

[0034] Figure 3 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 3 of the present application;

[0035] Figure 4 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 4 of the present application;

[0036] Figure 5 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 5 of the present application;

[0037] Figure 6 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 6 of the present application;

[0038] Figure 7 The scanning electron microscope image of the small particle size aluminum manganese doped cobalt oxyhydroxide prepared in the embodiment 7 of the present application. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0040] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0041] The embodiment of the present application provides a method for rapidly and efficiently preparing small particle size aluminum manganese doped cobalt oxyhydroxide, which comprises the following steps:

[0042] Step 1: mixing a cobalt source, an aluminum source, a manganese source, a complexing agent and an oxidizing agent in water to obtain a reaction solution; in the reaction solution, the content of cobalt element is 80-150 g / L, the weight ratio of metal elements of cobalt, aluminum and manganese is 1000:(1-16):(1-16); the oxidizing agent is hydrogen peroxide with a mass concentration of 20%-30%, the volume of hydrogen peroxide to the weight of cobalt element is 1:(3-8) mL / g; the complexing agent is citric acid, and the addition amount of citric acid is 1%-3% of the weight of cobalt element.

[0043] Step 2: A sodium hydroxide solution with a mass concentration of 30%-35% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%-80%; under the conditions that the stirring speed is 600-800 rpm and the temperature is 50-75℃, the reaction liquid is added to the sodium hydroxide solution, wherein the weight ratio of sodium hydroxide in the sodium hydroxide solution to cobalt in the reaction liquid is (0.8-1.4):1; the feeding time is controlled to be 2-3 min, and the reaction is performed for 5-10 min to obtain the product.

[0044] Step 3: The product is subjected to solid-liquid separation and washing by using a filter press or a centrifuge, and is subjected to drying treatment at a temperature of 80-95℃; finally, the product is crushed to a target particle size range by using a grinding or crushing machine in a crushing manner according to the application requirements of the product, so that the powdered small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide is obtained.

[0045] The application will be further described below in combination with specific examples, but is not limited to the application.

[0046] In the embodiments of the application, the cobalt source is cobalt chloride hexahydrate, the manganese source is manganese chloride tetrahydrate, and the aluminum source is aluminum chloride.

[0047] Example 1

[0048] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, which comprises the following steps:

[0049] Step 1: Cobalt source, aluminum source, manganese source, complexing agent and oxidizing agent are mixed in water to prepare 1L reaction liquid; in the reaction liquid, the content of cobalt element is 120g / L, and the weight ratio of metal elements of cobalt, aluminum and manganese is 1000:3:13 (aluminum chloride 2.04g, manganese chloride tetrahydrate 5.53g); the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount is 20mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.5g.

[0050] Step 2: A sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions that the stirring speed is 600 rpm and the temperature is 50℃, the reaction liquid is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 96g; the feeding time is controlled to be 2 min, and the reaction is performed for 5 min to obtain the product.

[0051] Step 3: The product is subjected to solid-liquid separation and washing by using a filter press or a centrifuge, and is subjected to drying treatment at a temperature of 85℃; the product is crushed by using a grinding manner to obtain aluminum-manganese-doped hydroxyl cobalt oxide with a particle size D50 of 4.226μm, and a scanning electron microscope image thereof is shown in Figure 1 .

[0052] Embodiment 2

[0053] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, which comprises the following steps:

[0054] Step 1: a cobalt source, an aluminum source, a manganese source, a complexing agent and an oxidizing agent are mixed in water to prepare 1L of a reaction solution; in the reaction solution, the content of cobalt element is 120g / L, the weight ratio of cobalt aluminum manganese is 1000:3:13 (aluminum chloride 2.04g, manganese chloride tetrahydrate 5.53g); the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount is 20mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.5g.

[0055] Step 2: a sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions of a stirring speed of 600 rpm and a temperature of 70°C, the reaction solution is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 96g; the feeding time is controlled to be 2min, and the reaction is performed for 5min to obtain a product.

[0056] Step 3: the product is subjected to solid-liquid separation and washing by using a filter press or a centrifuge, dried at 85°C, and subjected to crushing treatment by using grinding to obtain aluminum-manganese-doped hydroxyl cobalt oxide with a particle size D50 of 2.122μm, and a scanning electron microscope image thereof is shown in Figure 2 .

[0057] Embodiment 3

[0058] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, which comprises the following steps:

[0059] Step 1: a cobalt source, an aluminum source, a manganese source, a complexing agent and an oxidizing agent are mixed in water to prepare 1L of a reaction solution; in the reaction solution, the content of cobalt element is 120g / L, the weight ratio of cobalt aluminum manganese is 1000:3:10 (aluminum chloride 2.04g, manganese chloride tetrahydrate 4.18g); the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount is 20mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.8g.

[0060] Step 2: a sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions of a stirring speed of 600 rpm and a temperature of 70°C, the reaction solution is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 96g; the feeding time is controlled to be 2min, and the reaction is performed for 5min to obtain a product.

[0061] Step 3: The product is subjected to solid-liquid separation, washing by using a filter press or a centrifuge, drying treatment at 85°C, and broken by grinding to obtain aluminum-manganese-doped hydroxyl cobalt oxide with a particle size D50 of 2.483 μm, and a scanning electron microscope image as shown in Figure 3 .

[0062] Example 4

[0063] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, comprising the following steps:

[0064] Step 1: A cobalt source, an aluminum source, a manganese source, a complexing agent, and an oxidizing agent are mixed in water to prepare 1L of a reaction solution; in the reaction solution, the content of cobalt element is 120g / L, and the weight ratio of cobalt, aluminum, and manganese is 1000:3:10 (aluminum chloride 2.04g, manganese chloride tetrahydrate 4.18g); the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount is 15mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.8g.

[0065] Step 2: A sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions of a stirring speed of 600 rpm and a temperature of 70°C, the reaction solution is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 96g; the feeding time is controlled to be 2min, and the reaction is performed for 5min to obtain a product.

[0066] Step 3: The product is subjected to solid-liquid separation, washing by using a filter press or a centrifuge, drying treatment at 85°C, and broken by grinding to obtain aluminum-manganese-doped hydroxyl cobalt oxide with a particle size D50 of 2.534 μm, and a scanning electron microscope image as shown in Figure 4 .

[0067] Example 5

[0068] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, comprising the following steps:

[0069] Step 1: A cobalt source, an aluminum source, a manganese source, a complexing agent, and an oxidizing agent are mixed in water to prepare 1L of a reaction solution; in the reaction solution, the content of cobalt element is 120g / L, and the weight ratio of cobalt, aluminum, and manganese is 1000:3:10 (aluminum chloride 2.04g, manganese chloride tetrahydrate 4.18g); the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount is 15mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.8g.

[0070] Step 2: A sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions of a stirring speed of 800 rpm and a temperature of 75℃, the reaction liquid is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 168 g; the feeding time is controlled to be 3 min, and the reaction is carried out for 10 min to obtain a product.

[0071] Step 3: The product is subjected to solid-liquid separation and washing by using a filter press or a centrifuge, and is subjected to drying treatment at a temperature of 80℃; the product is subjected to crushing treatment by using grinding, and aluminum-manganese-doped cobalt oxyhydroxide with a particle size D50 of 2.786 μm is obtained, a scanning electron microscope image of which is shown in Figure 5

[0072] Example 6

[0073] The embodiment provides a method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped cobalt oxyhydroxide, which comprises the following steps:

[0074] Step 1: A cobalt source, an aluminum source, a manganese source, a complexing agent and an oxidizing agent are mixed in water to prepare 1 L of a reaction liquid; in the reaction liquid, the content of cobalt element is 120 g / L, and the weight ratio of metal elements of cobalt, aluminum and manganese is 1000:1:16; the oxidizing agent is hydrogen peroxide with a mass concentration of 30%, and the addition amount thereof is 39 mL; the complexing agent is citric acid, and the addition amount of citric acid is 1.2 g.

[0075] Step 2: A sodium hydroxide solution with a mass concentration of 32% is added to the reaction container, and the volume percentage of the sodium hydroxide solution in the reaction container is 60%; under the conditions of a stirring speed of 600 rpm and a temperature of 50℃, the reaction liquid is added to the sodium hydroxide solution, wherein the content of sodium hydroxide in the sodium hydroxide solution is 168 g; the feeding time is controlled to be 3 min, and the reaction is carried out for 10 min to obtain a product.

[0076] Step 3: The product is subjected to solid-liquid separation and washing by using a filter press or a centrifuge, and is subjected to drying treatment at a temperature of 85℃; the product is subjected to crushing treatment by using grinding, and aluminum-manganese-doped cobalt oxyhydroxide with a particle size D50 of 3.486 μm is obtained, a scanning electron microscope image of which is shown in Figure 6

[0077] Example 7

[0078] The main difference between the embodiment and Example 2 is that the product is subjected to crushing treatment by using air flow crushing in Step 3, the pressure of air flow crushing is 4 MPa, the frequency is 0.4 Hz, and the crushing treatment time is 1 h. After the above treatment, the particle size D50 of the product is 0.624 μm, and a scanning electron microscope image of the product is shown in Figure 7 ​​The smaller particle size product can be better distributed on the surface of the ternary cathode material, fill the gap, reduce the structure change of the ternary cathode material at high voltage, and effectively improve the rate and cycle performance of the battery.

[0079] Further, the products prepared in examples 1-7 are compared, and it is found that in the preparation method provided by the application, the reaction temperature, the doping amount, the amount of oxidizing agent and the crushing treatment are all key factors affecting the morphology and structure of the final product.

[0080] Among them, the products of comparative examples 1 and 2 are compared, and it is found that appropriately increasing the reaction temperature is more conducive to the generation of small particle size product, and the product generated at lower reaction temperature is not easy to crush, and contains relatively more impurities; the products of comparative examples 2 and 3 are compared, and it is found that reducing the manganese doping amount is conducive to the generation of smaller particles; the products of comparative examples 3 and 4 are compared, and it is found that the amount of hydrogen peroxide is also a key factor for the product to have the advantage of small particle size, and increasing the content of hydrogen peroxide is conducive to the generation of smaller particles; the products of comparative examples 2 and 7 are compared, and it is found that the crushing method also determines the particle size of the target product, and by using a more fine crushing method, the particle size of the product can be further reduced, which can better meet the application requirements of surface modification of ternary cathode material particles.

[0081] The above is only the preferred embodiment of the application, and does not limit the implementation and protection scope of the application. For those skilled in the art, it should be realized that any equivalent replacement and obvious changes made according to the content of the application should be included in the protection scope of the application.

Claims

1. A method for rapidly and efficiently preparing small-particle-size aluminum-manganese-doped hydroxyl cobalt oxide, characterized in that, The method comprises the following steps: S1, mixing a cobalt source, an aluminum source, a manganese source, a complexing agent and hydrogen peroxide in water to obtain a reaction solution; in the reaction solution, the content of cobalt element is 80-150 g / L, the weight ratio of cobalt, aluminum and manganese is 1000:(1-16):(1-16), the mass concentration of hydrogen peroxide is 20%-30%, the volume of hydrogen peroxide to the weight of cobalt is 1:(3-8) mL / g; the complexing agent is citric acid, and the addition amount of citric acid is 1%-3% of the weight of cobalt element; S2, under the conditions of stirring speed of 600-800 rpm and temperature of 50-75℃, the reaction solution is added into a sodium hydroxide solution, the feeding time is controlled to be 2-3 min, and the reaction time is controlled to be 5-10 min to obtain a product; S3, the product is subjected to solid-liquid separation, washing, drying and crushing treatment to obtain a small particle size aluminum-manganese doped hydroxyl cobalt oxide in powder form.

2. The method of claim 1, wherein, In step S1, the cobalt source includes one or more combinations of cobalt chloride, cobalt sulfate and cobalt nitrate.

3. The method of claim 1, wherein, In step S1, the aluminum source includes aluminum sulfate and / or aluminum chloride, and the manganese source includes one or more combinations of manganese chloride, manganese sulfate and manganese carbonate.

4. The method of claim 1, wherein, In step S2, the weight ratio of sodium hydroxide in the sodium hydroxide solution to cobalt element in the reaction solution is (0.8-1.4):

1.

5. The method of claim 1, wherein, In step S3, the solid-liquid separation is performed by a filter press or a centrifuge, and the drying temperature is 80-95℃.

6. The method of claim 1, wherein, In step S3, the crushing treatment includes grinding and / or crusher crushing.

7. A small particle size aluminum manganese doped cobalt oxyhydroxide characterized by, The small particle size aluminum-manganese doped hydroxyl cobalt oxide is prepared by the method according to any one of claims 1-6.

8. The use of a small particle size aluminum manganese doped hydroxyl cobalt oxide according to claim 7, characterized in that, The small particle size aluminum-manganese doped hydroxyl cobalt oxide is used as a coating material for surface modification of ternary positive electrode material particles.

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