阅读说明：本技术 一种镍钴铝前驱体的制备方法 (Preparation method of nickel-cobalt-aluminum precursor ) 是由 许开华 张坤 乐绪清 刘郁 任云强 邓安志 吴雨晴 李聪 余尚清 于 2021-09-08 设计创作，主要内容包括：本发明公开了一种镍钴铝前驱体的制备方法,包括：向反应器中加入底液并搅拌,通入惰性气体；将镍钴铝混合溶液、碱液和氨水同时加入反应器中进行共沉淀反应,得到镍钴铝氢氧化物浆料；将得到的镍钴铝氢氧化物浆料采用热碱洗涤,然后用纯水洗涤,得到镍钴铝洗涤半成品；将得到的镍钴铝洗涤半成品进行干燥,得到镍钴铝前驱体。通过调控镍钴氢氧化物材料合成过程的工艺,使前驱体具有比较细的一次颗粒,并均匀缠绕堆叠,形成均匀的孔隙,既保证电池前驱体的较高比容量也提高了电池前驱体的循环性能。(The invention discloses a preparation method of a nickel-cobalt-aluminum precursor, which comprises the following steps: adding the base solution into the reactor, stirring, and introducing inert gas; simultaneously adding the nickel-cobalt-aluminum mixed solution, alkali liquor and ammonia water into a reactor for coprecipitation reaction to obtain nickel-cobalt-aluminum hydroxide slurry; washing the obtained nickel-cobalt-aluminum hydroxide slurry by hot alkali, and then washing by pure water to obtain a nickel-cobalt-aluminum washing semi-finished product; and drying the obtained nickel-cobalt-aluminum washing semi-finished product to obtain a nickel-cobalt-aluminum precursor. By regulating and controlling the process of the nickel-cobalt hydroxide material synthesis process, the precursor has relatively fine primary particles, and is uniformly wound and stacked to form uniform pores, so that the high specific capacity of the battery precursor is ensured, and the cycle performance of the battery precursor is also improved.)

1. A method for preparing a nickel-cobalt-aluminum precursor, comprising:

(1) adding the base solution into the reactor, stirring, and introducing inert gas;

(2) simultaneously adding the nickel-cobalt-aluminum mixed solution, alkali liquor and ammonia water into the reactor obtained in the step (1) for coprecipitation reaction to obtain nickel-cobalt-aluminum hydroxide slurry;

(3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) by hot alkali for 1-4 times, and then washing by pure water for 1-4 times to obtain a nickel-cobalt-aluminum washing semi-finished product;

(4) and (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) to obtain a nickel-cobalt-aluminum precursor.

2. The method for preparing a nickel-cobalt-aluminum precursor according to claim 1, wherein the base solution in the step (1) is a mixed solution prepared by sequentially adding pure water, ammonia water and sodium hydroxide solution, the concentration of the ammonia water is 12% -22%, the concentration of the sodium hydroxide solution is 20% -40%, and the total volume of the base solution is 3m³-5.5m³And the ammonia concentration of the base solution is 6-10 g/L.

3. The method as claimed in claim 1, wherein the stirring speed in step (1) is 200-; the inert gas is nitrogen, and the introduction amount is 0.5-2m³/h。

4. The method for preparing a nickel-cobalt-aluminum precursor according to claim 1, wherein the molar ratio of nickel, cobalt and aluminum in the nickel-cobalt-aluminum mixed solution in the step (2) is (80-90): (5-15): (1-6), wherein the concentration of the nickel-cobalt-aluminum mixed solution is 80-120g/L, the flow rate is 300-550L/h, and the aluminum source is sodium metaaluminate; the concentration of the sodium hydroxide solution is 20-40%, and the flow rate is 40-120L/h; the concentration of the ammonia water is 12% -22%, and the flow rate is 30-60L/h.

5. The method for preparing nickel cobalt aluminum precursor as claimed in claim 1, wherein the coprecipitation reaction conditions in step (2) are as follows: the reaction temperature is 40-70 ℃, and the reaction time is 50-120 h.

6. The method for preparing the nickel-cobalt-aluminum precursor according to claim 1, wherein the step (3) is firstly washed with a hot sodium hydroxide solution with a concentration of 2-5% and a temperature of 40-80 ℃ for 10-40 min each time, and then washed with pure water with a temperature of 40-80 ℃ for 10-40 min each time.

7. The method for preparing the nickel-cobalt-aluminum precursor as claimed in claim 1, wherein the drying temperature in the step (4) is 100-170 ℃, and the particle size of the nickel-cobalt-aluminum precursor is 3-4 μm.

Technical Field

The invention relates to the field of nickel-cobalt-aluminum materials, in particular to a preparation method of a nickel-cobalt-aluminum precursor.

Background

The lithium ion battery is a new energy with wide application prospect, and is widely applied to the fields of electronic products, electric automobiles and the like. The ternary battery is widely applied to the field of new energy by virtue of the characteristics of high specific capacity and good cycle performance. With the increasing demand of society on the performance of lithium ion batteries, the production technology of lithium ion battery precursors needs to be updated continuously. At present, in order to pursue a battery with high specific capacity, the precursor is generally made to be compact and have high tap density, but the precursor is not beneficial to doping of lithium and diffusion of ions, so that the cycle performance of the battery is poor, but the specific capacity of the precursor which is too loose is low, and the requirement cannot be met. Both the higher specific capacity and the cycle performance of the precursor of the battery are ensured, and the precursor with compact primary particle combination and uniform pores is required to be produced.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides a preparation method of a fine primary particle nickel-cobalt-aluminum precursor.

The invention is realized by the following technical scheme.

A method for preparing a nickel-cobalt-aluminum precursor, comprising:

(1) adding the base solution into the reactor, stirring, and introducing inert gas;

(2) simultaneously adding the nickel-cobalt-aluminum mixed solution, alkali liquor and ammonia water into the reactor obtained in the step (1) for coprecipitation reaction to obtain nickel-cobalt-aluminum hydroxide slurry;

(3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) by hot alkali for 1-4 times, and then washing by pure water for 1-4 times to obtain a nickel-cobalt-aluminum washing semi-finished product;

(4) and (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) to obtain a nickel-cobalt-aluminum precursor.

Further, the base solution in the step (1) is a mixed solution prepared by sequentially adding pure water, ammonia water and a sodium hydroxide solution, wherein the concentration of the ammonia water is 12% -22%, the concentration of the sodium hydroxide solution is 20% -40%, and the total volume of the base solution is 3m³-5.5m³And the ammonia concentration of the base solution is 6-10 g/L.

Further, the stirring speed in the step (1) is 200-; the inert gas is nitrogen, and the introduction amount is 0.5-2m³/h。

Further, the nickel-cobalt-aluminum molar ratio in the nickel-cobalt-aluminum mixed solution in the step (2) is (80-90): (5-15): (1-6), wherein the concentration of the nickel-cobalt-aluminum mixed solution is 80-120g/L, the flow rate is 300-550L/h, and the aluminum source is sodium metaaluminate; the concentration of the sodium hydroxide solution is 20-40%, and the flow rate is 40-120L/h; the concentration of the ammonia water is 12% -22%, and the flow rate is 30-60L/h.

Further, the coprecipitation reaction conditions in the step (2) are as follows: the reaction temperature is 40-70 ℃, and the reaction time is 50-120 h.

Further, the step (3) is firstly washed by hot sodium hydroxide solution with the concentration of 2-5% and the temperature of 40-80 ℃ for 10-40 min each time, and then washed by pure water with the temperature of 40-80 ℃ for 10-40 min each time.

Further, the drying temperature in the step (4) is 100-170 ℃, and the granularity of the nickel-cobalt-aluminum precursor finished product is 3-4 μm.

The preparation method of the nickel-cobalt-aluminum precursor has the beneficial technical effects that the precursor has relatively fine primary particles by regulating and controlling the process of the nickel-cobalt hydroxide material synthesis process, and the precursor is uniformly wound and stacked to form uniform pores, so that the high specific capacity of the battery precursor is ensured, and the cycle performance of the battery precursor is also improved.

Drawings

Fig. 1 is a 10000 times SEM image of the nickel cobalt aluminum precursor material obtained by the present invention.

Fig. 2 is a 30000-fold SEM image of the nickel-cobalt-aluminum precursor material obtained by the present invention.

Fig. 3 is a cross-sectional SEM image of the nickel-cobalt-aluminum precursor material obtained by the present invention.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

A preparation method of a nickel-cobalt-aluminum precursor comprises the following steps:

(1) the preparation molar ratio is (80-90): (5-15): (1-6) a nickel-cobalt-aluminum mixed solution with the concentration of 80-120g/L, wherein an aluminum source is sodium metaaluminate, a nickel source is nickel sulfate, and a cobalt source is cobalt sulfate; adding quantitative pure water as bottom water into a reactor (specifically a reaction kettle), stirring at a rotation speed of 200-³Wherein the concentration of the added ammonia water is 12-22%, the concentration of the liquid alkali solution is 20-40%, the concentration of the ammonia in the base solution is 6-10g/L, the pH of the base solution is 10.0-12.0, inert gas nitrogen is introduced after the base solution is prepared, and the introduction amount is 0.5-2m³/h。

(2) Adding a mixed solution of nickel, cobalt and aluminum with the flow rate of 300-550L/h, a sodium hydroxide solution with the flow rate of 40-120L/h (the concentration is 20-40%), ammonia water with the flow rate of 30-60L/h (the concentration is 12-22%) into the reactor obtained in the step (1) simultaneously for coprecipitation reaction, wherein the temperature in the reaction process is 40-70 ℃, the pH value in the reaction process is 10.0-12.0, the rotation speed in the reaction process is 200-400r/min, the gradient decline is realized, the reaction time is 50-120h, and the nickel-cobalt-aluminum hydroxide slurry is obtained after the reaction is finished.

(3) And (3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) by using a hot sodium hydroxide solution with the concentration of 2-5% (40-80 ℃) for 1-4 times, 10-40 min each time, and then washing by using hot pure water with the temperature of 40-80 ℃ for 1-4 times, 10-40 min each time to obtain a nickel-cobalt-aluminum washing semi-finished product.

(4) And (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) by using drying equipment, wherein the drying temperature is 100-170 ℃ to obtain a nickel-cobalt-aluminum precursor of fine primary particles, and the particle size is 3-4 mu m.

The primary particles on the surface of the precursor prepared by the method are in a long and thin strip shape and are in a uniform winding shape, gaps can be generated between the primary particles, a spherical structure with uniform pores is formed, under the condition of ensuring the tap density, the ion diffusion channel is increased, the doping of a lithium source is facilitated, and the cycle performance of the battery precursor is also improved.

Example 1

A method for preparing an NCA precursor, comprising the steps of:

(1) preparing a nickel-cobalt-aluminum mixed solution with the molar ratio of 80:14:6 and the concentration of 80 g/L; adding quantitative pure water as bottom water into a reactor, stirring at 300r/min, adding ammonia water and sodium hydroxide solution to obtain a mixed solution as bottom liquid with a volume of 3m³Wherein the concentration of the added ammonia water is 12%, the concentration of the liquid alkali solution is 20%, the concentration of the ammonia of the base solution is 6g/L, the PH of the base solution is 10.0-12.0, inert gas nitrogen is introduced after the preparation of the base solution is finished, and the introduction amount is 0.5m³/h。

(2) And (2) simultaneously adding the nickel-cobalt-aluminum mixed solution with the flow rate of 300L/h, the sodium hydroxide solution with the flow rate of 40L/h (the concentration is 20%), and the ammonia water with the flow rate of 30L/h (the concentration is 12%) into the reactor obtained in the step (1) for coprecipitation reaction, wherein the temperature in the reaction process is 40 ℃, the rotating speed in the reaction process is 300r/min, the gradient is reduced to 200r/min, the reaction time is 120h, and the nickel-cobalt-aluminum hydroxide slurry is obtained after the reaction is finished.

(3) And (3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) with a hot sodium hydroxide solution (40 ℃) with the concentration of 2% for 4 times and 30min each time, and then washing with hot pure water at 40 ℃ for 4 times and 30min each time to obtain a nickel-cobalt-aluminum washing semi-finished product.

(4) And (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) by using drying equipment, wherein the drying temperature is 100 ℃ to obtain a nickel-cobalt-aluminum precursor of fine primary particles, and the average particle size is 3.0 mu m.

Example 2

A method for preparing an NCA precursor, comprising the steps of:

(1) preparing a nickel-cobalt-aluminum mixed solution with the molar ratio of 88:9:3 and the concentration of 105 g/L; adding quantitative pure water as bottom water into a reactor, stirring at 350r/min, adding ammonia water and sodium hydroxide solution to obtain mixed solution as bottom liquid with volume of 4.5m³Wherein the concentration of the added ammonia water is 17%, the concentration of the liquid alkali solution is 32%, the concentration of the ammonia of the base solution is 8g/L, the PH of the base solution is 10.0-12.0, inert gas nitrogen is introduced after the preparation of the base solution is finished, and the introduction amount is 1m³/h。

(2) And (2) simultaneously adding the nickel-cobalt-aluminum mixed solution with the flow rate of 400L/h, the sodium hydroxide solution (with the concentration of 32%) with the flow rate of 60L/h and the ammonia water (with the concentration of 17%) with the flow rate of 40L/h into the reactor obtained in the step (1) for coprecipitation reaction, wherein the temperature in the reaction process is 55 ℃, the pH value in the reaction process is 11.0-12.0, the rotation speed in the reaction process is 350r/min, the gradient descending is carried out to 220r/min, the reaction time is 90h, and the nickel-cobalt-aluminum hydroxide slurry is obtained after the reaction is finished.

(3) And (3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) with a hot sodium hydroxide solution (70 ℃) with the concentration of 3.5% for 2 times and 20min each time, and then washing with hot pure water at 70 ℃ for 2 times and 20min each time to obtain a nickel-cobalt-aluminum washing semi-finished product.

(4) And (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) by using drying equipment, wherein the drying temperature is 130 ℃ to obtain a nickel-cobalt-aluminum precursor of fine primary particles, and the average particle size is 3.5 mu m.

Example 3

A method for preparing an NCA precursor, comprising the steps of:

(1) preparing a nickel-cobalt-aluminum mixed solution with the molar ratio of 90:5:5 and the concentration of 120 g/L; adding quantitative pure water as bottom water into the reactor, stirring at 400r/min, adding ammonia water and sodium hydroxide solution to obtain mixed solution as bottom liquid with volume of 5.5m³Wherein the concentration of the added ammonia water is 22 percent, the concentration of the liquid alkali solution is 40 percent, the concentration of the ammonia of the base solution is 10g/L, the PH of the base solution is 10.0-12.0, and the base solution is standardAfter the preparation, inert gas nitrogen is introduced, and the introduction amount is 2m³/h。

(2) And (2) simultaneously adding the nickel-cobalt-aluminum mixed solution with the flow rate of 550L/h, the sodium hydroxide solution (the concentration is 40%) with the flow rate of 120L/h and the ammonia water (the concentration is 22%) with the flow rate of 60L/h into the reactor obtained in the step (1) for coprecipitation reaction, wherein the temperature in the reaction process is 70 ℃, the pH in the reaction process is controlled to be 11.2-12.0, the rotation speed in the reaction process is 400r/min, the gradient descending is carried out to 250r/min, the reaction time is 50h, and the nickel-cobalt-aluminum hydroxide slurry is obtained after the reaction is finished.

(3) And (3) washing the nickel-cobalt-aluminum hydroxide slurry obtained in the step (2) with a hot sodium hydroxide solution (80 ℃) with the concentration of 5% for 1 time and 40min each time, and then washing with hot pure water at 80 ℃ for 1 time and 40min each time to obtain a nickel-cobalt-aluminum washing semi-finished product.

(4) And (4) drying the nickel-cobalt-aluminum washed semi-finished product obtained in the step (3) by using drying equipment, wherein the drying temperature is 170 ℃ to obtain a nickel-cobalt-aluminum precursor of fine primary particles, and the average particle size is 4.0 mu m.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention. It should be noted that other equivalent modifications can be made by those skilled in the art in light of the teachings of the present invention, and all such modifications can be made as are within the scope of the present invention.