CN103232075B - Preparation method for cobalt oxyhydroxide - Google Patents

Abstract

The invention provides a preparation method of large particle spherical cobalt oxyhydroxide. The specific method is (1) prepare 0.5-2.0mol/L cobalt salt solution and 5-10mol/L sodium hydroxide solution, and add complexing agent and reducing agent to the sodium hydroxide solution; (2) under nitrogen protection Under certain conditions, pump the cobalt salt solution and sodium hydroxide solution prepared in step (1) into the reaction kettle at the same time, and control the pH value to 10-12 by adjusting the flow rate of the sodium hydroxide solution to continuously react. The slurry particle size is Between 15-20 microns; (3) Get cobaltous hydroxide with good sphericity and crystallinity, wash and filter, control the water content between 10-30%, transfer it to the oxidation kettle, blow in air, and carry out Oxidation; (4) Put the oxidized slurry into a blast oven and dry it to obtain.

Description

A kind of preparation method of cobalt oxyhydroxide

technical field

The invention relates to a preparation method of an inorganic material, in particular to a preparation method of cobalt oxyhydroxide.

Background technique

Since the 1980s, cobalt powder has been widely used in the field of rechargeable batteries as an activator for charging and discharging high-energy batteries. In the early 1990s, scientists from Japan, Germany and other countries successfully added sub-cobalt materials to battery raw materials, making it a high-value, high-tech product for the research and development of the battery industry. As a battery material additive with excellent performance, cobalt compounds such as cobalt powder and cobalt oxide powder can improve the proton conductance of Ni(OH) ₂ , reduce the oxidation potential, and increase the oxygen evolution potential, which has a significant effect on improving electrode performance. In the early stage of charging, it can ensure that the electrode is fully charged, so that Ni(OH) ₂ can be fully converted into NiOOH, and at the same time, the precipitation of oxygen can be suppressed, the charging efficiency can be improved, and the specific capacity of the electrode can be increased. In recent years, with the development of lithium-ion batteries, cobalt oxide is used as a raw material for the preparation of lithium-ion battery electrode materials, and its consumption is also increasing. China's lithium cobalt oxide production has developed rapidly in recent years, so the demand for Co ₃ 0 ₄ has also increased rapidly. Battery-grade Co ₃ 0 ₄ is the main raw material of lithium cobalt oxide, the cathode material of lithium-ion batteries, and it also increases with the demand for lithium-ion secondary batteries. Global cobalt consumption totaled 88 million pounds in 2002, and the share of cobalt applications in the battery industry has risen rapidly to 32%. With the further increase in the demand for small discrete mobile power sources, such as the rapid development of mobile communications and the rapid growth of the penetration rate of notebook computers, better opportunities have been created for the development of the lithium-ion battery industry. Correspondingly, for lithium-ion batteries The demand for cathode material LiCo0 ₂ has also increased significantly. It is estimated that the application of cobalt will reach 230 million pounds by 2015, 56% of which will be used in the lithium battery industry.

With the continuous development of portable electronic products, new requirements are constantly put forward for the batteries used in them. In particular, the ever-emerging smartphones and tablet PCs have higher requirements for battery life, especially tablet PCs, most of which use an embedded battery design structure, which cannot be disassembled. Battery life has become a weakness in its development. Lithium cobalt oxide is a so-called high-energy-density cathode material, which is the main cathode material for current smartphone and tablet batteries.

As one of the basic raw materials for the production of lithium cobalt oxide, cobalt oxyhydroxide is not only suitable for the preparation of various cobalt compounds, but also suitable for the preparation of lithium cobalt oxide, a positive electrode material for lithium-ion batteries with high activity. At the same time, cobalt oxyhydroxide can also be used as a Additives form a point-to-point network during the charging process to improve the charge-discharge performance and cycle life of the battery. Therefore, cobalt oxyhydroxide has a high development prospect.

Patent application 201210016504.3 discloses a preparation method of cobalt oxyhydroxide, which is to directly synthesize cobalt oxyhydroxide by adding an oxidizing agent during the reaction process. Patent application 201110327857.0 discloses a method for producing lithium cobaltate by wet chemical reaction to produce cobaltous hydroxide trivalent oxide. This method first synthesizes cobaltous hydroxide, and then oxidizes cobaltous hydroxide to hydroxyl trivalent oxidation by sodium hypochlorite. Cobalt, and finally sintered to make lithium cobaltate. Patent application 201010117854.X discloses a method for preparing cobalt trihydroxide, which is to synthesize cobalt trihydroxide by hydrothermal method. However, the morphology of the cobalt oxyhydroxide produced by the above-mentioned disclosed method is not spherical, which will cause uneven mixing in downstream industries, reduce the efficiency and effect of mixing, and the product stability is relatively poor. Adding an oxidizing agent during the synthesis process will cause The unevenness of the reaction is caused, making it difficult to mass-produce.

Contents of the invention

In view of the defects existing in the prior art, the object of the present invention is to provide a method for preparing large-particle spherical cobalt oxyhydroxide, which provides a highly stable raw material for mass production of lithium cobaltate, and increases the effect and efficiency of mixing materials.

In order to realize the purpose of the present invention, the present invention provides a kind of preparation method of cobalt oxyhydroxide, concrete steps are as follows:

(1) Prepare 0.5-2.0mol/L cobalt salt solution and 5-10mol/L sodium hydroxide solution, and add complexing agent and reducing agent to the sodium hydroxide solution;

(2) Under the conditions of pH 10-12, temperature 40-70°C, rotation speed 300-400 rpm and nitrogen protection, simultaneously pump the cobalt salt solution and hydrogen prepared in step (1) into the reactor Sodium oxide solution, and by adjusting the flow of sodium hydroxide solution to control the pH value of 10-12, continuous reaction, to obtain slurry;

(3) Get the cobaltous hydroxide with good sphericity and crystallinity, wash and filter, control the water content between 10-30%, transfer it to the oxidation kettle, blow in air, and oxidize;

(4) Put the oxidized slurry into a blast oven and dry it.

Specifically, the cobalt salt solution in the step (1) is one or more of CoSO ₄ , CoCl ₂ or Co ₃ (NO ₃ ) ₂ .

Preferably, the complexing agent added in the step (1) is 0.5-1.5L ammonia water with 25% ammonia content per liter of sodium hydroxide solution, or 50-100 grams of disodium edetate.

Preferably, the reducing agent added in the step (1) is 20-50 ml of 80% hydrazine hydrate solution per liter of sodium hydroxide solution.

Preferably, after the continuous reaction in the step (2), the particle size of the obtained slurry is controlled between 15-20 microns.

As a preference, in the step (3), it is transferred into an oxidation kettle, and air is blown in at a temperature of 100-200° C. for oxidation.

Preferably, the oxidation time is 3-6 hours.

As a preference, in the step (4), put the oxidized slurry into a blast oven and dry it at 120°C to obtain the finished product.

The present invention also provides the cobalt oxyhydroxide particles produced by the above preparation method.

The present invention also provides the application of the above preparation method in the production of cobalt oxyhydroxide.

The preparation method of a large-particle spherical cobalt oxyhydroxide provided by the invention, the cobalt oxyhydroxide produced is spherical, which can make the downstream industry mix evenly, and the product has strong stability, which can provide stability for mass production of lithium cobaltate Strong raw materials, increase the effect and efficiency of mixing.

Description of drawings

Fig. 1 is the XRD figure of the cobalt oxyhydroxide that a kind of preparation method of cobalt oxyhydroxide of the present invention makes;

Fig. 2 is the SEM picture of the cobalt oxyhydroxide that a kind of preparation method of cobalt oxyhydroxide of the present invention makes;

Fig. 3 is an SEM image of cobalt oxyhydroxide prepared according to the method for preparing cobalt oxyhydroxide disclosed in patent application 201210016504.3.

detailed description

The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

Example 1

1. Cobalt liquid configuration: Weigh 1.5 kg of cobalt chloride crystals, add deionized water to dissolve, and set the volume to 5 liters. In order to configure enough cobalt liquid, the above steps can be repeated;

2. Alkaline preparation: Weigh 1 kg of sodium hydroxide crystals, add deionized water to dissolve, set the volume to 3 liters, then add 0.7 L of ammonia water with 25% ammonia content and 20 ml of hydrazine hydrate solution with 80% content, and finally Set the volume to 5L, in order to configure enough lye, the above steps can be repeated;

3. Clean the reaction kettle, and pump the cobalt solution in step 1 and the lye solution in step 2 at the same time under the conditions of pH 11.1, temperature 65°C, rotation speed (300-rpm) and nitrogen protection, and adjust the hydrogen The flow rate of sodium oxide is stable and the pH value is controlled at 11.1, and the reaction is continuous. After 12 hours of feeding, the particle size of the slurry is detected to be between 15-20 microns, which is a qualified product at this time;

4. Take out the slurry with a particle size of 15-20 microns. After centrifugation and washing for 3 times, a pink material with a water content of 12% is obtained, and then transferred to the oxidation kettle, and the stirring is started to raise the temperature. The temperature is controlled at 150°C , air was blown in, and after 4 hours of oxidation, a black cobalt oxyhydroxide material was obtained.

5. Put the black material into a tray and put it into a blast oven, and after drying at 120°C, a black powdery product is obtained, which is the product cobalt oxyhydroxide. The XRD pattern of the obtained cobalt oxyhydroxide is shown in Figure 1, and the SEM pattern is similar to that in Figure 2.

Example 2.

1. Cobalt liquid configuration: Weigh 2.2 kg of cobalt chloride crystals, add deionized water to dissolve, and set the volume to 5 liters. In order to configure enough cobalt liquid, the above steps can be repeated;

2. Alkaline preparation: Weigh 1 kg of sodium hydroxide crystals, add deionized water to dissolve, and set the volume to 3 liters, then add 0.9L ammonia water with 25% ammonia content and 20 ml hydrazine hydrate solution with 80% content, and finally Set the volume to 5L, in order to configure enough lye, the above steps can be repeated;

3. Clean the reaction kettle, and pump the cobalt liquid in step 1 and the lye in step 2 at the same time under the protection conditions of pH value 10.9, temperature 50°C, rotation speed (350-rpm) and nitrogen gas, and adjust the hydrogen The flow rate of sodium oxide is stable and the pH value is controlled at 10.9, and the reaction is continuous. After 12 hours of feeding, the particle size of the slurry is detected to be between 15-20 microns, which is a qualified product at this time;

4. Take out the slurry with a particle size of 15-20 microns, centrifuge and wash 3 times to obtain a pink material with a water content of 12%, then transfer it to the oxidation kettle, start stirring to heat up, and control the temperature at 100°C , air was blown in, and after 3 hours of oxidation, a black cobalt oxyhydroxide material was obtained.

5. Put the black material into a tray and put it into a blast oven, and after drying at 120°C, a black powdery product is obtained, which is the product cobalt oxyhydroxide. The XRD pattern of the obtained cobalt oxyhydroxide is similar to that shown in Figure 1, and the SEM pattern is shown in Figure 2.

Example 3

1. Cobalt liquid configuration: Weigh 1.9 kg of cobalt sulfate crystals, add deionized water to dissolve, and set the volume to 5 liters. In order to configure enough cobalt liquid, the above steps can be repeated;

2. Alkaline preparation: Weigh 1 kg of sodium hydroxide crystals, add deionized water to dissolve, and set the volume to 3 liters, then add 0.9L ammonia water with 25% ammonia content and 20 ml hydrazine hydrate solution with 80% content, and finally Set the volume to 5L, in order to configure enough lye, the above steps can be repeated;

3. Clean the reaction kettle, and pump the cobalt solution in step 1 and the lye solution in step 2 at the same time under the conditions of pH 11.5, temperature 40°C, rotation speed (400-rpm) and nitrogen protection, and adjust the hydrogen The flow rate of sodium oxide is stable and the pH value is controlled at 11.5, and the reaction is continuous. After 12 hours of feeding, the particle size of the slurry is detected to be between 15-20 microns, which is a qualified product at this time;

4. Take out the slurry with a particle size of 15-20 microns. After centrifugation and washing for 3 times, a pink material with a water content of 12% is obtained, and then transferred to the oxidation kettle, and the stirring is started to raise the temperature. The temperature is controlled at 120°C , air was blown in, and after 5 hours of oxidation, a black cobalt oxyhydroxide material was obtained.

5. Put the black material into a tray and put it into a blast oven, and after drying at 120°C, a black powdery product is obtained, which is the product cobalt oxyhydroxide. The XRD pattern of the obtained cobalt oxyhydroxide is similar to that of Figure 1, and the SEM pattern is similar to that of Figure 2.

Example 4

1. Cobalt liquid configuration: Weigh 2.5 kg of cobalt chloride crystals, add deionized water to dissolve, and set the volume to 5 liters. In order to configure enough cobalt liquid, the above steps can be repeated;

2. Alkaline preparation: Weigh 2 kg of sodium hydroxide crystals, add deionized water to dissolve, and set the volume to 3 liters, then add 1.2 L of ammonia water with 25% ammonia content and 40 ml of hydrazine hydrate solution with 80% content, and finally Set the volume to 5L, in order to configure enough lye, the above steps can be repeated;

3. Clean the reaction kettle, and pump the cobalt solution in step 1 and the alkali solution in step 2 at the same time under the protection conditions of pH value 12, temperature 70°C, rotation speed (380-rpm) and nitrogen gas, and adjust the hydrogen The flow rate of sodium oxide is stable and the pH value is controlled at 12, and the reaction is continuous. After 12 hours of feeding, the particle size of the slurry is detected to be between 15-20 microns, which is a qualified product at this time;

4. Take out the slurry with a particle size of 15-20 microns, centrifuge and wash 3 times to obtain a pink material with a water content of 12%, then transfer it to the oxidation kettle, start stirring to heat up, and control the temperature at 180°C , air was blown in, and after 5 hours of oxidation, a black cobalt oxyhydroxide material was obtained.

5. Put the black material into a tray and put it into a blast oven, and after drying at 120°C, a black powdery product is obtained, which is the product cobalt oxyhydroxide. The XRD pattern of the obtained cobalt oxyhydroxide is similar to that of Figure 1, and the SEM pattern is similar to that of Figure 2.

Example 5

1. Cobalt liquid configuration: Weigh 2.2 kg of cobalt nitrate crystals, add deionized water to dissolve, and set the volume to 5 liters. In order to configure enough cobalt liquid, the above steps can be repeated;

2. Alkaline preparation: Weigh 2 kg of sodium hydroxide crystals, add deionized water to dissolve, and set the volume to 3 liters, then add 60 g of disodium edetate and 40 ml of 80% hydrazine hydrate solution , and finally set the volume to 5L. In order to configure enough lye, the above steps can be repeated;

3. Clean the reaction kettle, and pump the cobalt solution in step 1 and the alkali solution in step 2 at the same time under the protection conditions of pH value 10, temperature 45°C, rotation speed (340-rpm) and nitrogen gas, and adjust the hydrogen The flow of sodium oxide is stabilized and the pH value is controlled at 10, and the reaction is continuous. After 12 hours of feeding, the particle size of the slurry is detected to be between 15-20 microns, which is a qualified product at this time;

4. Take out the slurry with a particle size of 15-20 microns, centrifuge and wash 3 times to obtain a pink material with a water content of 12%, then transfer it to the oxidation kettle, start stirring to heat up, and control the temperature at 200°C , air was blown in, and after 6 hours of oxidation, a black cobalt oxyhydroxide material was obtained.

5. Put the black material into a tray and put it into a blast oven, and after drying at 120°C, a black powdery product is obtained, which is the product cobalt oxyhydroxide. The XRD pattern of the obtained cobalt oxyhydroxide is similar to that of Figure 1, and the SEM pattern is similar to that of Figure 2.

Example 6

According to the preparation method of cobalt oxyhydroxide disclosed in patent application 201210016504.3, the product cobalt oxyhydroxide was obtained. The obtained cobalt oxyhydroxide SEM image is shown in Figure 3.

By comparing Fig. 2 and Fig. 3, it can be clearly seen that the uniformity of the product obtained by the present invention is better, and the product obtained by the comparison file is closer to a spherical shape in shape, which is beneficial to the mixing uniformity of the downstream industry and the stability of the product , has a better effect, can provide a stable raw material for mass production of lithium cobalt oxide, and increase the effect and efficiency of mixing materials.

Although the present invention has been described in detail with general descriptions and specific embodiments above, it is obvious to those skilled in the art that some modifications or improvements can be made on the basis of the present invention. Therefore, the modifications or improvements made on the basis of not departing from the spirit of the present invention all belong to the protection scope of the present invention.

Claims (3)

1. a preparation method of cobalt oxyhydroxide, is characterized in that, concrete steps are as follows: (1) preparation of cobalt ion concentration is the cobalt salt solution of 0.5-2.0mol/L and the sodium hydroxide solution of 5-10mol/L, and adds complexing agent and reducing agent in sodium hydroxide solution; (2) At a pH value of 10-12, a temperature of 40-70°C, a rotating speed of 300-400 rpm and under the condition of nitrogen protection, simultaneously pump the cobalt salt solution and hydrogen prepared in step (1) into the reaction kettle Sodium oxide solution, and by adjusting the flow of sodium hydroxide solution to control the pH value of 10-12, continuous reaction, to obtain a slurry whose particle size is controlled between 15-20 microns; (3) Obtain cobaltous hydroxide with good sphericity and crystallinity, wash and filter, control the water content between 10-30%, transfer it to the oxidation kettle, and blow air into it at a temperature of 100-200°C to carry out Oxidation; oxidation time is 3-6 hours; (4) put the oxidized slurry into a blast oven, and dry to obtain final product; Wherein, the complexing agent added in the step (1) is to add 0.5-1.5L ammonia water with an ammonia content of 25% per liter of sodium hydroxide solution, or 50-100 grams of disodium edetate; The reducing agent added in the step (1) is to add 20-50 ml of 80% hydrazine hydrate solution per liter of sodium hydroxide solution. 2. The preparation method according to claim 1, characterized in that the cobalt salt solution in the step (1) is one or more of CoSO ₄ , CoCl ₂ or Co(NO ₃ ) ₂ . 3. The preparation method according to claim 1, characterized in that, in the step (4), put the oxidized slurry into a blast oven and dry it at 120°C to obtain the finished product.