CN116903050A - A preparation method of aluminum nickel manganese magnesium doped with cobalt tetroxide - Google Patents

Abstract

The invention discloses a preparation method of aluminum-nickel-manganese-magnesium doped cobaltosic oxide, which comprises the following steps: s1: mixing aluminum salt, magnesium salt, nickel salt, manganese salt and cobalt salt to obtain a mixed solution; s2: the mixed solution prepared in the step S1, a precipitator and a complexing agent are introduced into a reaction kettle containing base solution after being parallel-flow, and the reaction is carried out at the temperature of 35-50 ℃ under the pH value of 7.0-7.5 to prepare the aluminum-nickel-manganese-magnesium doped cobaltosic oxide precursor; s3: calcining the aluminum-nickel-manganese-magnesium doped cobaltosic oxide precursor prepared in the step S2 to obtain aluminum-nickel-manganese-magnesium doped cobaltosic oxide; the invention provides a preparation method of cobaltosic oxide, which improves the stability of a material structure, increases the conductivity of the material and improves the migration efficiency in the lithium ion charging and discharging process through the synergistic effect of multiple elements by multi-element doping.

Description

A preparation method of aluminum nickel manganese magnesium doped with cobalt tetroxide

Technical field

The invention relates to the technical field of battery material preparation, and specifically relates to a preparation method of aluminum, nickel, manganese and magnesium doped with cobalt tetroxide.

Background technique

With the upgrading of 3C products and the launch of various high-end wearable devices, people's requirements for lithium-ion batteries are getting higher and higher. Cathode material manufacturers often mix large and small particles to increase the compaction density of the cathode, thereby improving the lithium-ion battery. energy density. Tricobalt tetroxide is an important precursor for preparing lithium cobalt oxide, a cathode material for lithium batteries. Its various indicators affect the performance of lithium cobalt oxide cathode materials and downstream lithium-ion batteries. The structure of the existing lithium cobalt oxide material synthesized by tricobalt tetroxide has increased to a certain extent. Improves stability, but cannot meet the needs of higher voltage lithium cobalt oxide such as 4.48V and 4.5V.

Therefore, there is an urgent need to develop a preparation method of cobalt tetroxide that can solve the problem that the current lithium cobalt oxide material structure synthesized by cobalt tetroxide cannot meet the requirements of higher voltage lithium cobalt oxide such as 4.48V and 4.5V.

Contents of the invention

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a preparation method of cobalt tetroxide. Through multi-element doping and the synergistic effect of multiple elements, it not only improves the stability of the material structure, but also increases the conductivity of the material and improves the migration of lithium ions during charge and discharge. Efficiency, the lithium cobalt oxide material synthesized with tricobalt tetroxide in the present invention can meet the demand for higher voltage lithium cobalt oxide such as 4.48V and 4.5V.

A method for preparing aluminum nickel manganese magnesium doped with cobalt tetroxide according to the first embodiment of the present invention includes the following steps:

S1: Mix aluminum salt, magnesium salt, nickel salt, manganese salt and cobalt salt to obtain a mixed solution;

S2: The mixed solution, precipitant and complexing agent prepared in step S1 are flowed together and then passed into the reaction kettle containing the bottom liquid. The pH value is 7.0~7.5 and the reaction temperature is 35~50°C to prepare aluminum nickel. Manganese magnesium doped cobalt tetroxide precursor;

S3: Calcining the aluminum nickel manganese magnesium doped cobalt tetroxide precursor prepared in step S2 to obtain aluminum nickel manganese magnesium doped cobalt tetroxide.

Embodiments according to the first aspect of the present invention have at least the following beneficial effects:

In the present invention, through multi-element doping, the synergistic effect of multiple elements not only improves the stability of the material structure, but also increases the conductivity of the material and improves the migration efficiency of lithium ions during the charge and discharge process. Among them, aluminum improves the structure of the material. Stability, magnesium can form columnar shapes to inhibit phase change, and can also increase the conductivity of the material to reduce the impedance during charge and discharge. Nickel-manganese doping can convert the phase change into solid solution behavior, inhibiting the phase change, making the material consist of aluminum, nickel, and manganese. Lithium cobalt oxide prepared by magnesium doping with cobalt tetraoxide can meet higher voltage requirements.

According to some embodiments of the present invention, in step S1, the cobalt salt includes at least one of cobalt chloride, cobalt sulfate, and cobalt nitrate.

According to some embodiments of the present invention, in step S1, the cobalt ion concentration in the mixed solution is 80-150g/L.

According to some embodiments of the present invention, in step S1, the concentration of aluminum ions in the mixed solution is 0.5-2.2g/L.

According to some embodiments of the present invention, the concentration of nickel ions in the mixed solution is 0.15-0.55g/L.

According to some embodiments of the present invention, the concentration of manganese ions in the mixed solution is 0.1-0.63g/L.

According to some embodiments of the present invention, the concentration of magnesium ions in the mixed solution is 0.14-0.53g/L.

According to some embodiments of the present invention, the aluminum salt includes at least one of aluminum sulfate, aluminum chloride and aluminum nitrate.

According to some embodiments of the present invention, the nickel salt includes at least one of nickel sulfate, nickel chloride and nickel nitrate.

According to some embodiments of the present invention, the manganese salt includes at least one of manganese sulfate, manganese chloride and manganese nitrate.

According to some embodiments of the present invention, the magnesium salt includes at least one of magnesium sulfate, magnesium chloride and magnesium nitrate.

According to some embodiments of the present invention, the precipitating agent includes at least one of ammonium bicarbonate, sodium carbonate and sodium bicarbonate.

According to some embodiments of the present invention, the complexing agent includes at least one of ammonia, EDTA and citric acid.

According to some embodiments of the present invention, in step S2, the particle size of the aluminum nickel manganese magnesium doped cobalt tetroxide precursor is 18 to 19 μm.

According to some embodiments of the present invention, in step S2, the reaction process includes a stirring reaction.

According to some embodiments of the present invention, in step S2, the stirring speed is 200 to 400 rpm.

According to some preferred embodiments of the present invention, in step S2, the method for controlling the particle size of the aluminum-nickel-manganese-magnesium-doped cobalt tetroxide precursor to be 18-19 μm is to separate the reaction kettle every 80 hours and reduce the seed crystal by half. , the corresponding flow rate and rotation speed are reduced by 20%, until the particle size of the four-element doping precursor reaches 18-19 μm in 160-260 hours, and the kettle is stopped.

According to some embodiments of the present invention, in step S3, washing is also included before the calcination.

According to some embodiments of the present invention, in step S3, the calcination temperature is 800-900°C; the calcination time is 4-5 hours.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention.

Description of the drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

Figure 1 is a schematic diagram of aluminum nickel manganese magnesium doped cobalt carbonate particles obtained in Example 1 under a 3000x scanning electron microscope (SEM);

Figure 2 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 30,000x scanning electron microscope (SEM);

Figure 3 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 10000x scanning electron microscope (SEM);

Figure 4 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 5000x scanning electron microscope (SEM);

Figure 5 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 3000x scanning electron microscope (SEM);

Figure 6 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 1000x scanning electron microscope (SEM);

Figure 7 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 500x scanning electron microscope (SEM).

Figure 8 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt carbonate particles obtained in Example 2 under a 3000x scanning electron microscope (SEM);

Figure 9 is a schematic diagram of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 2 under a 3000x scanning electron microscope (SEM);

Detailed ways

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and cannot be understood as limiting the present invention.

Example 1

This embodiment discloses a preparation method of aluminum nickel manganese magnesium doped with cobalt tetroxide. The process includes the following steps:

A1: Prepare a mixed salt solution of cobalt, aluminum, nickel, manganese and magnesium. The cobalt salt is cobalt chloride with a concentration of 110g/L; the aluminum salt is aluminum sulfate with an aluminum ion concentration of 1.46g/L; the nickel salt is nickel sulfate with a concentration of 0.24 g/L; the manganese salt is manganese sulfate, with a concentration of 0.19g/L; the magnesium salt is magnesium sulfate, with a concentration of 0.26g/L;

A2: Prepare ammonium bicarbonate solution with a concentration of 240g/L; ammonia concentration is 140g/L;

A3: Add cobalt aluminum nickel manganese magnesium mixed salt solution, ammonium bicarbonate solution, and ammonia water into a reaction kettle whose bottom liquid is 130g/L ammonium bicarbonate solution in parallel flow. The amount of bottom liquid added just covers the bottom stirring paddle of the reaction kettle. Cobalt The feed of aluminum, nickel, manganese and magnesium mixed salt solution is 50mL/min, the feed of ammonium bicarbonate solution is 55mL/min, the feed of ammonia water is 8mL/min, the system reaction temperature is 40℃, the system reaction pH is 7.0~7.5, every 80h The reaction kettle is divided into kettles, the seed crystal is halved, and the corresponding flow rate and rotation speed are reduced by 20% until 160 to 260 hours to obtain aluminum nickel manganese magnesium doped cobalt carbonate with a particle size of 18 to 19 μm;

A4: Wash the aluminum nickel manganese magnesium doped cobalt carbonate in step A3 until the chloride ion content is less than 100 ppm, then place it in a rotary furnace and calcine at 800°C for 4 hours to obtain aluminum nickel manganese magnesium doped cobalt tetroxide;

A5: Take the aluminum nickel manganese magnesium doped cobalt tetroxide prepared by A4 and conduct scanning electron microscopy. The electron microscopy results are shown in Figures 2 to 7. From Figure 2, it can be seen that the material has a spherical shape, a smooth surface, and uniform doping elements. The main physical and chemical indicators of the material are shown in Table 1. The tap density of the four-element co-doped cobalt tetroxide is 2.12g/cm ³ , the actual aluminum element concentration is 9018ppm, the nickel element concentration is 1109ppm, the manganese element concentration is 1264ppm, and the magnesium element concentration It is 1366ppm; the physical and chemical indicators are shown in Table 2.

A6: Al-nickel-manganese-magnesium doped with cobalt tetroxide was fired into lithium cobalt oxide. The electrical performance test (4.55V) at 0.1C was 181.7mAh/g, and the capacity retention rate after 50 cycles was 98.3%.

Figure 1 is a picture of the aluminum nickel manganese magnesium doped cobalt carbonate particles obtained in Example 1 under a 3000x scanning electron microscope (SEM);

Figure 2 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 30,000x scanning electron microscope (SEM);

Figure 3 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 10,000x scanning electron microscope (SEM);

Figure 4 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 5000x scanning electron microscope (SEM);

Figure 5 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 3000x scanning electron microscope (SEM);

Figure 6 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 1000x scanning electron microscope (SEM);

Figure 7 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 1 under a 500x scanning electron microscope (SEM).

Table 1: Main physical and chemical indicators of aluminum, nickel, manganese and magnesium doped with cobalt tetroxide

Example 2

A1: Prepare a mixed salt solution of cobalt, aluminum, nickel, manganese and magnesium. The cobalt salt is cobalt chloride with a concentration of 80g/L; the aluminum salt is aluminum sulfate with an aluminum ion concentration of 0.943g/L; the nickel salt is nickel sulfate with a concentration of 0.177 g/L; the manganese salt is manganese sulfate, with a concentration of 0.266g/L; the magnesium salt is magnesium sulfate, with a concentration of 0.187g/L;

A2: Prepare ammonium bicarbonate solution with a concentration of 200g/L; ammonia concentration is 100g/L;

A3: Add cobalt aluminum nickel manganese magnesium mixed salt solution, ammonium bicarbonate solution, and ammonia water into a reaction kettle whose bottom liquid is 100g/L ammonium bicarbonate solution. The amount of bottom liquid added just covers the bottom stirring paddle of the reaction kettle. Cobalt The feed of aluminum, nickel, manganese and magnesium mixed salt solution is 70mL/min, the feed of ammonium bicarbonate solution is 65mL/min, the feed of ammonia water is 12mL/min, the system reaction temperature is 40℃, the system reaction pH is 7.0~7.5, every 80h The reaction kettle is divided into kettles, the seed crystal is halved, and the corresponding flow rate and rotation speed are reduced by 20% until 160 to 260 hours to obtain aluminum nickel manganese magnesium doped cobalt carbonate with a particle size of 18 to 19 μm;

A4: Wash the aluminum nickel manganese magnesium doped cobalt carbonate in step A3 until the chloride ion content is less than 100 ppm, then place it in a rotary furnace and calcine at 800°C for 4 hours to obtain aluminum nickel manganese magnesium doped cobalt tetroxide;

A5: Take the aluminum nickel manganese magnesium doped cobalt tetroxide prepared by A4 and conduct scanning electron microscopy. The electron microscopy results are shown in Figures 7 to 9. From Figure 8, it can be seen that the material has a spherical shape, a smooth surface, and uniform doping elements. The main physical and chemical indicators of the material are shown in Table 2. The tap density of the four-element co-doped cobalt tetroxide is 2.18g/cm ³ , the actual aluminum element concentration is 7995ppm, the nickel element concentration is 1118ppm, the manganese element concentration is 2326ppm, and the magnesium element concentration is 1348ppm; the physical and chemical indicators are shown in Table 2.

A6: Al-nickel-manganese-magnesium doped with cobalt tetroxide was fired into lithium cobalt oxide. The electrical performance test (4.55V) at 0.1C was 182.4mAh/g, and the capacity retention rate after 50 cycles was 97.6%.

Figure 8 is a picture of the aluminum nickel manganese magnesium doped cobalt carbonate particles obtained in Example 2 under a 3000x scanning electron microscope (SEM);

Figure 9 is a picture of the aluminum nickel manganese magnesium doped cobalt tetroxide obtained in Example 2 under a 3000x scanning electron microscope (SEM);

Table 2: Main physical and chemical indicators of aluminum nickel manganese magnesium doped cobalt tetroxide

Comparative example 1

A1: Prepare a cobalt-aluminum mixed salt solution, in which the cobalt salt is cobalt chloride with a concentration of 110g/L; the aluminum salt is aluminum sulfate with an aluminum ion concentration of 1.46g/L;

A2: Prepare ammonium bicarbonate solution with a concentration of 240g/L; ammonia concentration is 140g/L;

A3: Add the cobalt-aluminum mixed salt solution, ammonium bicarbonate solution, and ammonia water into a reaction kettle whose bottom liquid is 130g/L ammonium bicarbonate solution in parallel flow. The amount of the bottom liquid added just covers the bottom stirring paddle of the reaction kettle. The cobalt-aluminum mixed salt solution The solution feed is 50mL/min, the ammonium bicarbonate solution feed is 55mL/min, the ammonia water feed is 8mL/min, the system reaction temperature is 40°C, the system reaction pH is 7.0~7.5, and the reaction kettle is separated every 80 hours. During the treatment, the seed crystal is halved, and the corresponding flow rate and rotation speed are reduced by 20% until 160 to 260 hours to obtain aluminum-doped cobalt carbonate with a particle size of 18 to 19 μm;

A4: Wash the aluminum-doped cobalt carbonate in step A3 until the chloride ion content is less than 100 ppm, then place it in a rotary furnace and calcine it at 800°C for 4 hours to obtain aluminum-doped cobalt tetroxide with a tap density of 2.27g/ ^cm3 . The actual aluminum element concentration of cobalt tetroxide is 8957ppm;

A5: Aluminum-doped cobalt tetroxide is fired into lithium cobalt oxide. The electrical performance test (4.55V) at 0.1C is 179.6mAh/g, and the capacity retention rate after 50 cycles is 96.7%.

Comparative example 2

A1: Prepare a cobalt-aluminum mixed salt solution, in which the cobalt salt is cobalt chloride with a concentration of 80g/L; the aluminum salt is aluminum sulfate with an aluminum ion concentration of 0.943g/L;

A2: Prepare ammonium bicarbonate solution with a concentration of 200g/L; ammonia concentration is 100g/L;

A3: Add the cobalt-aluminum mixed salt solution, ammonium bicarbonate solution, and ammonia water into a reaction kettle whose bottom liquid is 100g/L ammonium bicarbonate solution in parallel flows. The amount of the bottom liquid added just covers the bottom stirring paddle of the reaction kettle. The cobalt-aluminum mixed salt solution The solution feed is 70mL/min, the ammonium bicarbonate solution feed is 65mL/min, the ammonia water feed is 12mL/min, the system reaction temperature is 40°C, the system reaction pH is 7.0~7.5, and the reaction kettle is separated every 80 hours. During the treatment, the seed crystal is halved, and the corresponding flow rate and rotation speed are reduced by 20% until 160 to 260 hours to obtain aluminum-doped cobalt carbonate with a particle size of 18 to 19 μm;

A4: Wash the aluminum-doped cobalt carbonate in step A3 until the chloride ion content is less than 100 ppm, then place it in a rotary furnace and calcine it at 800°C for 4 hours to obtain aluminum-doped cobalt tetroxide with a tap density of 2.19g/ ^cm3 . The actual aluminum element concentration of cobalt tetroxide is 7957ppm;

A5: Aluminum-doped cobalt tetroxide is fired into lithium cobalt oxide. The electrical performance test (4.55V) at 0.1C is 180.3mAh/g, and the capacity retention rate after 50 cycles is 94.5%.

The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various modifications can be made without departing from the purpose of the present invention. Variety.

Claims (10)

1. A method for preparing aluminum nickel manganese magnesium doped with cobalt tetroxide, which is characterized by comprising the following steps: S1: Mix aluminum salt, magnesium salt, nickel salt, manganese salt and cobalt salt to obtain a mixed solution; S2: The mixed solution, precipitant and complexing agent prepared in step S1 are flowed together and then passed into the reaction kettle containing the bottom liquid. The pH value is 7.0~7.5 and the reaction temperature is 35~50°C to prepare aluminum nickel. Manganese magnesium doped cobalt tetroxide precursor; S3: Calcining the aluminum nickel manganese magnesium doped cobalt tetroxide precursor prepared in step S2 to obtain aluminum nickel manganese magnesium doped cobalt tetroxide. 2. The preparation method according to claim 1, wherein in step S1, the cobalt salt includes at least one of cobalt chloride, cobalt sulfate, and cobalt nitrate. 3. The preparation method according to claim 1, characterized in that in step S1, the cobalt ion concentration in the mixed solution is 80-150g/L. 4. The preparation method according to claim 1, characterized in that in step S1, in the mixed solution, the concentration of aluminum ions is 0.5~2.2g/L; preferably, in the mixed solution, the concentration of nickel ions is The concentration is 0.15~0.55g/L; preferably, the concentration of manganese ions in the mixed solution is 0.1~0.63g/L; preferably, the concentration of magnesium ions in the mixed solution is 0.14~0.53g/L . 5. The preparation method according to claim 1, characterized in that the aluminum salt includes at least one of aluminum sulfate, aluminum chloride and aluminum nitrate. 6. The preparation method according to claim 1, wherein the nickel salt includes at least one of nickel sulfate, nickel chloride and nickel nitrate. 7. The preparation method according to claim 1, wherein the manganese salt includes at least one of manganese sulfate, manganese chloride and manganese nitrate. 8. The preparation method according to claim 1, wherein the magnesium salt includes at least one of magnesium sulfate, magnesium chloride and magnesium nitrate. 9. The preparation method according to claim 1, wherein the precipitating agent includes at least one of ammonium bicarbonate, sodium carbonate and sodium bicarbonate; preferably, the complexing agent includes ammonia, EDTA and At least one of citric acid. 10. The preparation method according to claim 1, characterized in that, in step S1, the particle size of the aluminum nickel manganese magnesium doped cobalt tetroxide precursor is 18 to 19 μm; preferably, in step S3, the particle size of the aluminum nickel manganese magnesium doped cobalt tetroxide precursor is 18-19 μm; Including washing; preferably, in step S3, the calcination temperature is 800-900°C; the calcination time is 4-5 hours.