CN112582605B - Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process - Google Patents
Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process Download PDFInfo
- Publication number
- CN112582605B CN112582605B CN202011352509.4A CN202011352509A CN112582605B CN 112582605 B CN112582605 B CN 112582605B CN 202011352509 A CN202011352509 A CN 202011352509A CN 112582605 B CN112582605 B CN 112582605B
- Authority
- CN
- China
- Prior art keywords
- reaction
- concentration
- slurry
- cobalt
- nickel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
The invention discloses a preparation method of a nickel-cobalt-manganese ternary precursor with reduced sulfur content in a continuous production process, which comprises the steps of injecting slurry into a washing kettle after concentration by a concentrator, washing off sulfur impurities on the surface of the precursor by hot alkali, then injecting the slurry into a reaction kettle again after concentration by the concentrator, and continuously growing precursor particles to a target diameter; wherein, the volume of the slurry in the reaction kettle is reduced after concentration, alkaline washing and concentration, at the moment, a complexing agent with the same ammonia concentration as that of the reaction bottom liquid is injected from V4, and the pH value of the reaction is automatically adjusted by a feedback system to be stable. The preparation method of the invention not only reduces the SO of the solution in the reaction kettle 4 2‑ Concentration and can wash off the SO on the surface in the growth process of the particles 4 2‑ Thereby greatly reducing the content of sulfur impurities coated in the particles and simultaneously improving the crystallinity and the true density of the precursor.
Description
Technical Field
The invention belongs to the technical field of preparation of ternary precursors of lithium ion batteries, and particularly relates to a preparation method of a nickel-cobalt-manganese ternary precursor with low sulfur content.
Background
Due to excellent electrochemical performance, the lithium ion battery is widely applied to the fields of 3C, electric automobiles, electric tools, energy storage, wearable electronic products and the like. The ternary nickel-cobalt-manganese anode material is a lithium ion battery anode material with excellent performances in all aspects, the ternary precursor is a main raw material for producing the ternary anode material, and the particle size distribution, the morphology, the impurity content and the like of the precursor are closely related to the physical and chemical properties of the anode material.
The coprecipitation method is the main method for producing the precursor industrially at present, and the adopted salt raw material is sulfate. There is a large amount of SO in the synthesis process 4 2- The sulfate radical on the surface of the precursor can be removed by washing with hot alkali or hot pure water, and the crystallinity of the precursor can be damaged by excessive alkali washing, so that the product quality is poor. For example, CN107459069B and CN103342395B disclose methods of reducing sulfur content by alkali washing after removing mother liquor from precursors, but such a method of alkali washing the surface of the final product of the precursors can only wash away sulfur impurities on the surface, and it is difficult to wash away the SO wrapped inside the particles 4 2- . The sulfur impurities wrapped inside are also high, the sintered precursor with high S impurity content can lead to poor cycle performance of the obtained anode material, and the capacity is low, so that the produced lithium ion battery can not meet the market requirement.
CN107611383B and CN110817975B disclose methods for removing supernatant and then reducing the sulfur content in a precursor by alkaline washing a filter cake, mainly reducing SO in the supernatant 4 2- The content of S impurities in the precursor is reduced, but the method still cannot effectively reduce SO coated in the particles 4 2- 。
Therefore, a method is still needed, which can effectively reduce the content of S impurities in the precursor and on the surface of the precursor, and can avoid excessive alkali washing, so as to improve the crystallinity of the precursor and improve the cycle performance of the cathode material.
Disclosure of Invention
The invention aims to provide a preparation method of a nickel-cobalt-manganese ternary precursor for reducing sulfur content in a continuous production process, aiming at overcoming the defects of the prior art, so that the S impurity content in the interior and on the surface of the precursor can be effectively reduced, and the crystallinity of the ternary precursor can be effectively improved.
In order to achieve the purpose, the invention adopts the following technical scheme:
a preparation method of a nickel-cobalt-manganese ternary precursor for reducing sulfur content in a continuous production process comprises the steps of taking sulfates of nickel, cobalt and manganese, alkali and a complexing agent as raw materials, synthesizing the ternary precursor to a target granularity in a reaction kettle through coprecipitation, and aging, washing, drying and sieving to obtain a ternary precursor material, and is characterized in that the synthesis of the precursor is divided into two stages:
1) A nucleation stage: forming a large amount of micro particles by adopting high pH, high stirring speed and low feeding speed;
2) And (3) growth stage: the particles grow up rapidly by adopting low pH, low stirring speed and high feeding speed;
wherein, the particle size distribution is detected every 1 hour in the growth stage, and the alkali washing operation is carried out according to the size of the volume particle size distribution D50; preferably, the alkaline washing operation comprises the following steps:
s1, stopping feeding of sulfate, alkali and a complexing agent, concentrating slurry discharged from a reaction kettle in a concentrator 1, discharging clear liquid, improving solid content of the slurry, and discharging SO in the solution 4 2- ；
S2, feeding the concentrated slurry into a washing kettle, flushing the surface of spherical particles by utilizing thermokalite under the stirring action, and enabling SO on the surface of the particles 4 2- Removing;
and S3, pumping the washed slurry into a thickener 2 through a pump, filtering redundant clear liquid of the slurry, pumping the filtered slurry into the reaction kettle again, and continuously growing the small spherical particles returned to the reaction kettle through a coprecipitation reaction.
In a specific embodiment, after the slurry is concentrated, washed with alkali and concentrated and returned to the reaction kettle, complexing agent with the same concentration as the reaction condition is injected into the reaction kettle immediately, the pH value of the reaction is automatically adjusted by a feedback system to maintain stability, and then the slurry is fed again to ensure that the small spherical particles returned to the reaction kettle continue to grow.
In a particular embodiment, the base in the feedstock is selected from any one of NaOH or KOH, preferably NaOH; the complexing agent is selected from any one or more of ammonia water, urea, ammonium acetate, ammonium sulfate, ammonium carbonate, ammonium chloride and ammonium nitrate, and is preferably ammonia water.
In a specific embodiment, the pH value of the reaction kettle system in the nucleation stage is 11.5-12.0, the stirring speed is 800-1500rpm, and the feeding speed of the salt solution is 1-3L/h; and finishing the nucleation stage after the volume particle size distribution D50 of the precursor reaches 3 mu m.
In a specific embodiment, the pH value of the reaction kettle system in the growth stage is 10.0-11.5, the stirring speed is 200-800rpm, and the feeding speed of the salt solution is 3-8L/h; and after the volume particle size distribution D50 of the precursor reaches 10 mu m, finishing the growth stage and beginning to age.
In a specific embodiment, the particle size distribution is measured every 1 hour during the growth phase, and a hot alkali washing operation is performed every 2 μm to 3 μm increase according to the particle volume particle size distribution D50 until the growth reaches the target particle size.
In a preferred embodiment, the growth phase comprises a first growth phase and a second growth phase, the pH of the reaction kettle system of the first growth phase is 11.0-11.5, the stirring speed is 500-800rpm, and the feeding speed of the salt solution is 3-5L/h; starting alkali washing operation after the first stage, and ending the first growth stage after the volume particle size distribution D50 of the precursor reaches 7 mu m; preferably, after the first growth stage is finished, the reaction enters a second growth stage, the alkali washing operation is continued, the pH value of the reaction kettle system is 10.0-11.0, the stirring rotation speed is 200-500rpm, and the feeding speed of the salt solution is 5-8L/h; and after the volume particle size distribution D50 of the precursor reaches 10 mu m, finishing the growth stage and beginning to age.
In a particular embodiment, the thermal base is selected from any one of sodium hydroxide, potassium hydroxide, barium hydroxide, preferably sodium hydroxide; the temperature of the hot alkali is 40-90 ℃, preferably 50-60 ℃; the concentration of the sodium hydroxide solution is 1-10 mol/L, preferably 2-4 mol/L.
In a specific embodiment, the pH of the reaction base solution is 11 to 13, preferably 11.2 to 11.9, the ammonia concentration is 0.2 to 0.6mol/L, preferably 0.25 to 0.5, the reaction temperature is 40 ℃ to 70 ℃, preferably 50 to 60 ℃, the rotation speed of the stirring paddle is 50 to 800rpm, preferably 400 to 800rpm, and the feeding speed of the salt solution is 1L/h to 8L/h, preferably 3L/h to 6L/h.
In a specific embodiment, the concentration kettle is a device with a stirring function, and can discharge clear slurry liquid and leave solid phase in the kettle to improve the solid content of the slurry.
In a specific embodiment, the nickel-cobalt-manganese ternary precursor has the chemical formula of Ni x Co y Mn z (OH) 2 Wherein x + y + z =1, and x is more than 0.20 and less than 0.90, y is more than 0.05 and less than 0.40, and z is more than 0.05 and less than 0.40.
Compared with the prior art, the invention has the following beneficial effects:
in the process of precursor synthesis, the particle size of the precursor grows to different stages, and hot alkali is continuously used for washing the surface of precipitate particles to ensure that SO 4 2- Removing; and the complexing agent with the same reaction condition is continuously used for replacing the clear liquid in the reaction kettle, SO that the SO in the reaction kettle is effectively reduced 4 2- Content of SO preventing the particles from being grown 4 2- The coating is coated inside the particles, so that S impurities inside the particles are reduced, and the problem that the S impurities of the precursor product exceed the standard is solved. Meanwhile, the preparation method disclosed by the invention can also avoid the problem of poor precursor crystallinity caused by excessive alkali cleaning by controlling the alkali cleaning time, the alkali solution concentration and the cleaning time, and can obtain a ternary precursor material with good crystallization property and high true density.
Drawings
FIG. 1 is a schematic process flow diagram of the preparation method of the present invention.
Fig. 2 is an XRD spectrum of the ternary precursor prepared in example 1 and comparative example 3.
FIG. 3 is an SEM image of ternary precursors prepared in example 1 (right) and comparative example 3 (left) of the present invention.
Wherein, 1-reaction kettle, 2 concentration kettle A,3 washing kettle, 4 concentration kettle B,5 pump, 6 feed line, 7 concentration component, 8 thermokalite.
Detailed Description
The following examples will further illustrate the method provided by the present invention in order to better understand the technical solution of the present invention, but the present invention is not limited to the listed examples, and should also include any other known modifications within the scope of the claims of the present invention.
As shown in fig. 1, in the preparation method of the nickel-cobalt-manganese ternary precursor with reduced sulfur content in the continuous production process of the present invention, a coprecipitation reaction of the ternary precursor is performed in a reaction kettle 1 with a stirring device, the coprecipitation reaction includes a nucleation stage and a growth stage, the reaction solution is transferred to a concentration kettle A2, the concentration kettle A2 includes a concentration member 7, clear solution is separated through concentration, slurry is transferred to a washing kettle 3, the ternary precursor slurry with high solid content enters the washing kettle 3 through a thermokalite 8, the slurry is transferred to a concentration kettle B4 for further concentration after thermokalite washing, the concentrated slurry is returned to the reaction kettle 1 again, raw materials with the same concentration as the original reaction solution are added through a feeding pipeline 6 for continuous growth, and the concentration, washing and concentration steps are repeated according to different growth stages. The process of the specific preparation method is further described as follows:
1) Preparing nickel sulfate, cobalt sulfate, manganese sulfate and pure water into a salt solution with a certain concentration.
2) And adding the mixed salt solution, the complexing agent and the sodium hydroxide solution into a reaction kettle which is continuously stirred, and carrying out coprecipitation reaction to obtain the nickel-cobalt-manganese ternary precursor.
Further, reaction base liquid is required to be prepared before the reaction starts, the reaction base liquid can be 1/2-2/3 of the effective volume of the reaction kettle, and the pH value and the ammonia concentration of the reaction base liquid are the same as those of the reaction conditions. In general, the reaction base solution is sodium hydroxide solution and ammonia solution, the concentration of which is not limited at all, the main function is to provide an initial growth environment for the triple precursor coprecipitation, and the pH of the reaction base solution is generally adjusted to be in the range of 11-13, preferably 11.2-11.9. For example, the concentration of the sodium hydroxide solution used for preparing the reaction base solution is 4 to 10mol/L, and the concentration of the aqueous ammonia solution is 0.2 to 0.6mol/L, preferably 0.25 to 0.5mol/L; the temperature of the reaction bottom liquid is set to 40 ℃ to 70 ℃, preferably 50 ℃ to 60 ℃.
3) The first stage of the reaction is a nucleation stage, the reaction pH value is high, the stirring speed is high, the feeding speed is low, a large number of small crystal nuclei are formed in the reaction kettle, and then the small crystal nuclei are agglomerated into 3 mu m micro spherical particles. The second stage of the reaction is a growth stage, the pH value of the reaction is reduced, the stirring speed is reduced, the salt feeding speed is increased, and the growth of the tiny spherical particles is promoted. During the growth of the particles, the particle size distribution was measured every 1 hour using a laser particle sizer. According to different requirements on the content of S impurities, alkali washing operation can be carried out when the volume particle size distribution D50 grows to different stages.
Further, the pH value of the reaction kettle system in the nucleation stage is 11.5-12.0, the stirring speed is 800-1500rpm, and the feeding speed of the salt solution is 1-3L/h; after the volume particle size distribution D50 of the precursor reaches 3 mu m, the nucleation stage is finished; the pH value of the growth stage reaction kettle system is 10.0-11.5, the stirring speed is 200-800rpm, and the feeding speed of the salt solution is 3-8L/h; and after the volume particle size distribution D50 of the precursor reaches 10 mu m, finishing the growth stage and beginning aging.
Furthermore, the growth stage comprises a first growth stage and a second growth stage, the pH of the reaction kettle system of the first growth stage is 11.0-11.5, the stirring speed is 500-800rpm, and the feeding speed of the salt solution is 3-5L/h; starting alkali washing operation after the first stage, and ending the first growth stage after the volume particle size distribution D50 of the precursor reaches 7 mu m; preferably, after the first growth stage is finished, the reaction enters a second growth stage, the alkali washing operation is continued, the pH value of the reaction kettle system is 10.0-11.0, the stirring rotation speed is 200-500rpm, and the salt solution feeding speed is 5-8L/h; and after the volume particle size distribution D50 of the precursor reaches 10 mu m, finishing the growth stage and beginning to age.
4) Stopping feeding sulfate, alkali and complexing agent during alkaline washing, concentrating the slurry discharged from the reaction kettle in a concentrator A, discharging clear liquid, increasing the solid content of the slurry, and discharging SO in the solution 4 2- . The concentrated slurry is injected into a washing kettle, and under the stirring action, hot alkali at 40-90 ℃ is used for washing the surface of spherical particles, SO on the surface of the particles 4 2- And (5) removing.
The concentration kettles A and B are devices with stirring function and concentration components, which can discharge clear slurry, leave solid phase in the kettles and improve solid content of the slurry. Specifically, for example, the concentrating member is a hollow fiber membrane.
5) And after the hot alkali washing is finished, the slurry in the hot alkali tank is pumped into a thickener B through a diaphragm pump, redundant clear liquid of the slurry is filtered and then pumped into the reaction kettle again, and after all the slurry in the reaction kettle is concentrated, alkali washed and concentrated, the solid content is very high, so that the dispersion in the particle growth process in the kettle is not facilitated. At the moment, a complexing agent with the same concentration as that under the reaction condition is injected into the reaction kettle through a complexing agent replenishing port of the feeding pipeline, the pH value in the kettle is controlled by the pH automatic adjustment feedback system to maintain stable, when the volume of the slurry in the kettle reaches 1/2-2/3 of the effective volume, the feeding of the sulfate, the alkali and the complexing agent is restarted, and the small spherical particles returning to the reaction kettle continue to grow through the coprecipitation reaction.
During the growth of the particles, the SO on the surface of the particles is washed away by hot alkali for a plurality of times 4 2- Simultaneously, the complexing agent is added to replace the reaction solution, SO in the clear liquid is reduced 4 2- The content of S impurities coated inside during the growth of the particles can be greatly reduced.
Further, the particle size distribution is detected every 1 hour in the growth stage, and hot alkali washing operation is performed every 2-3 μm according to the increase of the particle volume particle size distribution D50 until the particles grow to a target particle size, for example, more than 10 μm, which can be specifically determined according to the downstream customer requirements.
6) And stopping feeding and starting an aging reaction when the particle size of the precipitate reaches the target particle size, and washing, drying and sieving to obtain the ternary precursor material after the completion of the aging reaction.
Wherein, the aging, washing, drying, sieving and the like are all conventional operations in the field, and refer to the post-treatment process of the ternary precursor material in the prior art, such as aging for 4h, washing for 2-3 times by deionized water, drying at 120 ℃, and sieving to obtain the ternary precursor material with the required target particle size D50. The chemical formula of the nickel-cobalt-manganese ternary precursor can be expressed as Ni x Co y Mn z (OH) 2 Wherein x + y + z =1 and 0.20 < x < 0.90,0.05 < y < 0.40,0.05 < z < 0.40.
The preparation process according to the invention is further illustrated, without any limitation, by the following more specific examples.
The following examples and comparative examples used the following main raw materials:
NiSO nickel sulfate hexahydrate 4 ·6H 2 O, battery grade, jinchuan group;
cobalt sulfate heptahydrate CoSO 4 ·7H 2 O, battery grade, cobalt friendly industry;
manganese sulfate monohydrate MnSO 4 ·H 2 O, battery grade, new materials ltd, assembled by dazohong, guizhou;
polyvinylidene fluoride (PVDF), analytically pure, aladine;
ammonia, analytically pure, alatin;
ammonium bicarbonate, analytically pure, alatin.
The related performance test method of the ternary precursor material is as follows:
electrochemical test equipment, a Shenzhen New Wei button cell test system;
roasting equipment, namely a combined fertilizer crystal tube type furnace with the model of OTF-1500X;
an inorganic chemical product crystal structure analysis X-ray diffraction method (GB/T30904-2014);
the method for measuring the physical and mechanical properties of coal and rock comprises the following steps: coal and rock true density determination methods (GB/T23561.2-2009);
ICP test method (EPA 6010D-2014).
The invention is further illustrated, but not limited, by the following more specific examples.
Example 1:
(1) Firstly, preparing 50L of reaction base solution by using ammonia water and sodium hydroxide, enabling the pH of the prepared reaction base solution to be 11.7 and the ammonia concentration to be 0.4mol/L, heating the reaction base solution by using jacket water bath to enable the temperature to be 60 ℃, and introducing nitrogen to carry out oxygen removal treatment on the reaction base solution. The method comprises the steps of simultaneously injecting a nickel-cobalt-manganese sulfate solution, ammonia water and sodium hydroxide into a 100L reaction kettle, setting the stirring speed to be 1000rpm, the temperature of a reaction system to be 60 ℃, the ammonia concentration in the reaction kettle to be 0.4mol/L and the pH value to be 11.7, wherein the molar ratio of nickel, cobalt and manganese in a mixed salt solution is 6.
(2) The reaction is started to be a nucleation stage, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is 2L/h, the flow rate of the raw material liquid ammonia is 0.3L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.7, the rotating speed of a stirring paddle is 1000rpm, the particle size distribution is tested by a laser particle size analyzer every 1 hour, and the nucleation stage is ended after the volume particle size distribution D50 reaches 3 mu m.
(3) After the nucleation is finished, the reaction enters a first stage of nuclear growth, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow of the metal salt solution is increased to 4L/h, the water flow of raw material liquid ammonia is increased to 0.6L/h, the flow of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.3, the rotating speed of a stirring paddle is reduced to 700rpm, the particle size distribution is tested every 1 hour by using a laser particle size analyzer, when the particle size distribution D50 reaches 4 mu m, the feeding of the metal salt solution, the ammonia water and the sodium hydroxide solution is stopped, a liquid discharge port of the reaction kettle is opened, 1/2 volume of slurry in the kettle is discharged into a concentration kettle 1, clear liquid is discharged through concentration operation, the concentrated slurry is pumped into a washing kettle by using a pneumatic diaphragm pump, and the SO on the surfaces of the particles is removed by stirring and washing with hot alkali of 2mol/L sodium hydroxide at 50 ℃ for 20min 4 2- Discharging the residual slurry in the reaction kettle into a concentration kettle 1 for concentration operation, pumping the slurry into a concentration kettle 2 by using a pneumatic diaphragm pump after hot alkali washing in a washing kettle is finished, and pumping the slurry into the reaction kettle again after removing the redundant alkali liquor; through twice concentration, alkali washing and concentration operations, the volume of slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through a liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.2 by a pH automatic adjusting feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, the liquid supplementing is stopped, the feeding of a metal salt solution, a sodium hydroxide solution and the ammonia water is restarted, and the small spherical particles returned to the reaction kettle continue to grow up through coprecipitation reaction.
(4) And (3) when the volume particle size distribution D50 reaches 7 micrometers, allowing the reaction to enter a second nuclear growth stage, injecting a metal salt solution, a sodium hydroxide solution and ammonia water into the reaction kettle through an electric diaphragm pump, increasing the flow of the metal salt solution to 6L/h, increasing the flow of the raw material liquid ammonia to 0.9L/h, automatically adjusting the flow of the sodium hydroxide solution through a feedback control system to control the pH to be 10.8, reducing the rotating speed of a stirring paddle to 400rpm to ensure that the growth speed of the spherical particles is kept relatively stable, and performing the alkaline washing operation in the step 3 in the process.
(5) The concentration, alkali washing and concentration operations are carried out once when the particle volume particle size distribution D50 is increased by 2 mu m.
(6) And after the particle size reaches 10 mu m, aging the slurry in the reaction kettle for 4 hours, then putting the slurry into a hot alkali washing kettle for alkali washing, then putting the slurry into a centrifuge for washing by using pure water, demagnetizing the washed material, drying and sieving to obtain the product.
(7) Weighing 120g of LiOH and 456g of Ni (OH) according to the proportion that nLi to n (Ni + Co + Mn) is 1 2 @Co(OH) 2 @Mn(OH) 2 Mixing completely, placing in a tube furnace, introducing oxygen, heating to 400 ℃ at the speed of 10 ℃/min, preserving heat for 1h, heating to 820 ℃ at the same heating speed, preserving heat for 12h, cooling the tube furnace, taking out a sample, and obtaining the lithium ion battery anode material LiNiO 2 @LiCoO 2 @LiMnO 2 。
Example 2:
the other operations are completely the same as the steps of example 1, except that in the step (5), concentration, alkali washing and concentration operations are performed once when the particle volume particle size distribution D50 is increased by 2 μm, and concentration, alkali washing and concentration operations are performed once when the particle volume particle size distribution D50 is increased by 3 μm.
Example 3:
(1) Firstly, 50L of reaction base solution is prepared by ammonia water and sodium hydroxide, so that the pH value of the reaction base solution is 11.5, the ammonia concentration is 0.4mol/L, the temperature of the reaction base solution is heated by jacket water bath to be 60 ℃, and the reaction base solution is deoxygenated by introducing nitrogen. The method comprises the steps of simultaneously injecting a nickel-cobalt-manganese sulfate solution, ammonia water and sodium hydroxide into a 100L reaction kettle, setting the stirring speed to be 1000rpm, setting the temperature of a reaction system to be 60 ℃, the ammonia concentration to be 0.4mol/L, the sodium hydroxide concentration to be 10mol/L and the pH value to be 11.5, wherein the molar ratio of nickel, cobalt and manganese in the mixed salt solution is 6.
(2) The reaction is started to be a nucleation stage, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is 1L/h, the flow rate of raw material liquid ammonia is 0.15L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.5, the rotating speed of a stirring paddle is 800rpm, the particle size distribution is tested by a laser particle sizer every 1 hour, and the nucleation stage is ended after the volume particle size distribution D50 reaches 3 mu m.
(3) After the nucleation is finished, the reaction enters a first stage of nuclear growth, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is increased to 3L/h, the water flow rate of raw material liquid ammonia is increased to 0.45L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.0, the rotating speed of a stirring paddle is reduced to 500rpm, the particle size distribution is tested once every 1 hour by using a laser particle size analyzer, when the particle size distribution D50 reaches 4 mu m, the feeding of the metal salt solution, the ammonia water and the sodium hydroxide solution is stopped, a liquid discharge port of the reaction kettle is opened, 1/2 volume of slurry in the kettle is discharged into a concentration kettle 1, the concentrated clear liquid is discharged through concentration operation, the concentrated clear liquid is pumped into a washing kettle through a pneumatic diaphragm pump, and is stirred and washed by hot alkali of 2mol/L of sodium hydroxide at 50 ℃ for 20min to remove SO on the surfaces of the particles 4 2- Discharging the residual slurry in the reaction kettle into a concentration kettle 1 for concentration operation, pumping the slurry into a concentration kettle 2 by using a pneumatic diaphragm pump after hot alkali washing in a washing kettle is finished, and pumping the slurry into the reaction kettle again after removing the redundant alkali liquor; after twice concentration, alkali washing and concentration operations, the volume of the slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through a liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.0 by a pH automatic adjusting feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, the liquid supplementing is stopped, and the metal salt solution, the sodium hydroxide solution and the ammonia solution are restartedFeeding water, and continuously growing the small spherical particles returned to the reaction kettle through coprecipitation reaction.
(4) And (3) when the volume particle size distribution D50 reaches 7 micrometers, allowing the reaction to enter a second nuclear growth stage, injecting a metal salt solution, a sodium hydroxide solution and ammonia water into the reaction kettle through an electric diaphragm pump, increasing the flow of the metal salt solution to 5L/h, increasing the flow of the raw material liquid ammonia to 0.75L/h, automatically adjusting the flow of the sodium hydroxide solution through a feedback control system to control the pH to be 10.5, reducing the rotating speed of a stirring paddle to 200rpm to ensure that the growth speed of the spherical particles is kept relatively stable, and performing the alkaline washing operation in the step 3 in the process.
(5) The concentration, alkali washing and concentration operations are carried out once when the particle volume particle size distribution D50 is increased by 2 mu m.
(6) And after the particle size reaches 10 mu m, aging the slurry in the reaction kettle for 4 hours, then putting the slurry into a hot alkali washing kettle for alkali washing, then putting the slurry into a centrifuge for washing by using pure water, demagnetizing the washed material, drying and sieving to obtain the product.
(7) Weighing 120g of LiOH and 456g of Ni (OH) according to the proportion of nLi: n (Ni + Co + Mn) as 1 2 @Co(OH) 2 @Mn(OH) 2 Mixing completely, placing in a tube furnace, introducing oxygen, heating to 400 ℃ at the speed of 10 ℃/min, preserving heat for 1h, heating to 820 ℃ at the same heating speed, preserving heat for 12h, cooling the tube furnace, taking out a sample, and obtaining the lithium ion battery anode material LiNiO 2 @LiCoO 2 @LiMnO 2 。
Example 4:
(1) Firstly, 50L of reaction base solution is prepared by ammonia water and sodium hydroxide, so that the pH value of the reaction base solution is 12.0, the ammonia concentration is 0.4mol/L, the reaction base solution is heated by jacket water bath at the temperature of 60 ℃, and the reaction base solution is deoxygenated by introducing nitrogen. The method comprises the steps of simultaneously injecting a nickel-cobalt-manganese sulfate solution, ammonia water and sodium hydroxide into a 100L reaction kettle, setting the stirring speed to be 1500rpm, the temperature of a reaction system to be 60 ℃, the ammonia concentration to be 0.4mol/L and the pH value to be 12.0, wherein the molar ratio of nickel, cobalt and manganese in a mixed salt solution is 6.
(2) The reaction is started to be a nucleation stage, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is 3L/h, the flow rate of the raw material liquid ammonia is 0.45L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 12.0, the rotating speed of a stirring paddle is 1500rpm, the particle size distribution is tested by a laser particle size analyzer every 1 hour, and the nucleation stage is ended after the volume particle size distribution D50 reaches 3 mu m.
(3) After the nucleation is finished, the reaction enters a first stage of nuclear growth, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow of the metal salt solution is increased to 5L/h, the water flow of raw material liquid ammonia is increased to 0.75L/h, the flow of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.5, the rotating speed of a stirring paddle is reduced to 800rpm, the particle size distribution is tested every 1 hour by using a laser particle size analyzer, when the particle size distribution D50 reaches 4 mu m, the feeding of the metal salt solution, the ammonia water and the sodium hydroxide solution is stopped, a liquid discharge port of the reaction kettle is opened, 1/2 volume of slurry in the kettle is discharged into a concentration kettle 1, clear liquid is discharged through concentration operation, the concentrated slurry is pumped into a washing kettle through a pneumatic diaphragm pump, and the SO on the surfaces of the particles is removed by stirring and washing with hot alkali of 2mol/L sodium hydroxide at 50 ℃ for 20min 4 2- Discharging the residual slurry in the reaction kettle into a concentration kettle 1 for concentration operation, pumping the slurry into a concentration kettle 2 by using a pneumatic diaphragm pump after hot alkali washing in a washing kettle is finished, and pumping the slurry into the reaction kettle again after removing the redundant alkali liquor; through twice concentration, alkali washing and concentration operations, the volume of slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through a liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.5 by a pH automatic adjusting feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, the liquid supplementing is stopped, the feeding of a metal salt solution, a sodium hydroxide solution and the ammonia water is restarted, and the small spherical particles returned to the reaction kettle continue to grow up through coprecipitation reaction.
(4) And (3) when the volume particle size distribution D50 reaches 7 micrometers, allowing the reaction to enter a second nuclear growth stage, injecting a metal salt solution, a sodium hydroxide solution and ammonia water into the reaction kettle through an electric diaphragm pump, increasing the flow of the metal salt solution to 8L/h, increasing the flow of the raw material liquid ammonia to 1.2L/h, automatically adjusting the flow of the sodium hydroxide solution through a feedback control system to control the pH to be 11.0, reducing the rotating speed of a stirring paddle to 500rpm to ensure that the growth speed of the spherical particles is kept relatively stable, and performing the alkaline washing operation in the step 3 in the process.
(5) The concentration, alkali washing and concentration operations are carried out once when the particle volume particle size distribution D50 is increased by 2 mu m.
(6) And after the particle size reaches 10 mu m, aging the slurry in the reaction kettle for 4 hours, then putting the slurry into a hot alkali washing kettle for alkali washing, then putting the slurry into a centrifuge for washing by using pure water, demagnetizing the washed material, drying and sieving to obtain the product.
(7) Weighing 120g of LiOH and 456g of Ni (OH) according to the proportion that nLi to n (Ni + Co + Mn) is 1 2 @Co(OH) 2 @Mn(OH) 2 Mixing completely, placing in a tube furnace, introducing oxygen, heating to 400 deg.C at a rate of 10 deg.C/min, maintaining for 1h, heating to 820 deg.C at the same heating rate, maintaining for 12h, cooling in the tube furnace, taking out the sample to obtain LiNiO as the anode material of lithium ion battery 2 @LiCoO 2 @LiMnO 2 。
Example 5
(1) Firstly, preparing 50L of reaction base solution by using ammonia water and sodium hydroxide, enabling the pH of the prepared reaction base solution to be 11.6 and the ammonia concentration to be 0.4mol/L, heating the reaction base solution by using jacket water bath to enable the temperature to be 60 ℃, and introducing nitrogen to carry out oxygen removal treatment on the reaction base solution. The method comprises the steps of simultaneously injecting a nickel-cobalt-manganese sulfate solution, ammonia water and sodium hydroxide into a 100L reaction kettle, setting the stirring speed to be 900rpm, the temperature of a reaction system to be 60 ℃, the ammonia concentration in the reaction kettle to be 0.4mol/L and the pH value to be 11.6, wherein the molar ratio of nickel, cobalt and manganese in a mixed salt solution is 6.
(2) The reaction is started to be a nucleation stage, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is 3L/h, the water flow rate of raw material liquid ammonia is 0.45L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.6, the rotating speed of a stirring paddle is 900rpm, the particle size distribution is tested by a laser particle sizer every 1 hour, and the nucleation stage is ended after the volume particle size distribution D50 reaches 3 mu m.
(3) After the nucleation is finished, the reaction enters a nuclear growth stage, a metal salt solution, a sodium hydroxide solution and ammonia water are injected into a reaction kettle through an electric diaphragm pump, the flow rate of the metal salt solution is increased to 6L/h, the water flow rate of raw material liquid ammonia is increased to 0.9L/h, the flow rate of the sodium hydroxide solution is automatically adjusted through a feedback control system to control the pH value to be 11.0, the rotating speed of a stirring paddle is reduced to 600rpm, the particle size distribution is tested once every 1 hour by using a laser particle size analyzer, when the particle size distribution D50 reaches 4 mu m, the feeding of the metal salt solution, the ammonia water and the sodium hydroxide solution is stopped, a liquid discharge port of the reaction kettle is opened, 1/2 volume of slurry in the kettle is discharged into a concentration kettle 1, clear liquid is discharged through concentration operation, the concentrated slurry is pumped into a washing kettle by using a pneumatic diaphragm pump, and the SO4 on the surface of the particles is removed by stirring and washing with hot alkali of 2mol/L sodium hydroxide at 50 ℃ for 20min 2- Discharging the residual slurry in the reaction kettle into a concentration kettle 1 for concentration operation, pumping the slurry into a concentration kettle 2 by using a pneumatic diaphragm pump after hot alkali washing in a washing kettle is finished, and pumping the slurry into the reaction kettle again after removing the redundant alkali liquor; through twice concentration, alkali washing and concentration operations, the volume of slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through a liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.0 by an automatic pH adjusting feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, the liquid supplementing is stopped, the feeding of a metal salt solution, a sodium hydroxide solution and the ammonia water is restarted, and small spherical particles returning to the reaction kettle continue to grow up through coprecipitation reaction.
(4) The concentration, alkali washing and concentration operations are carried out once when the particle volume particle size distribution D50 is increased by 2 mu m.
(5) And after the particle size reaches 10 mu m, aging the slurry in the reaction kettle for 4 hours, then putting the slurry into a hot alkali washing kettle for alkali washing, then putting the slurry into a centrifuge for washing by using pure water, demagnetizing the washed material, drying and sieving to obtain the product.
(6) Weighing 120g of LiOH and 456g of Ni (OH) according to the proportion of nLi: n (Ni + Co + Mn) as 1 2 @Co(OH) 2 @Mn(OH) 2 Mixing completely, placing in a tube furnace, introducing oxygen, heating to 400 ℃ at the speed of 10 ℃/min, preserving heat for 1h, heating to 820 ℃ at the same heating speed, preserving heat for 12h, cooling the tube furnace, taking out a sample, and obtaining the lithium ion battery anode material LiNiO 2 @LiCoO 2 @LiMnO 2 。
Comparative example 1:
the other operations were completely the same as those of example 1 except that after the clear liquid was discharged by the concentration operation in the step (3), the slurry was not subjected to alkali washing.
Discharging clear liquid through concentration operation in the step (3), and pumping concentrated slurry into a reaction kettle by using a pneumatic diaphragm pump; through concentration operation, the volume of slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through the liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.2 by the pH automatic adjustment feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, liquid supplementing is stopped, feeding of a metal salt solution, a sodium hydroxide solution and the ammonia water is restarted, and small spherical particles returning to the reaction kettle continue to grow up through coprecipitation reaction.
Comparative example 2:
the other operations were completely the same as those in example 1, except that after the clear solution was discharged by the concentration operation in the step (3), the slurry was not subjected to alkali washing, and no new complexing agent solution was supplied after the slurry was returned to the reaction vessel.
And (3) when the particle volume and particle size distribution D50 reaches 4 micrometers, pumping the slurry in the reaction kettle into a concentration kettle, concentrating, discharging clear liquid, pumping the concentrated slurry into the reaction kettle by using a pneumatic diaphragm pump, and allowing the particles to grow up in the reaction solution again.
Comparative example 3:
the other operations are completely the same as the steps of example 1, except that the concentration, alkali washing and concentration operations are changed to the concentration, alkali washing and concentration operations every time the particle volume particle size distribution D50 in the step (5) is increased by 2 microns.
Comparative example 4:
the other operations were completely the same as those of example 1 except that the hot alkali washing with 2mol/L of 50 ℃ sodium hydroxide in step (3) was changed from 20 minutes to 40 minutes by 6mol/L of 50 ℃ sodium hydroxide.
Because the concentration of the sodium hydroxide solution in the alkali washing process is too high, the alkali washing time is too long, and a product with the D50 of 10 mu m is not synthesized.
Comparative example 5:
compared with example 1, the difference is that the coprecipitation reaction is not divided into a nucleation stage and a growth stage, i.e. the coprecipitation reaction is carried out according to reaction conditions such as uniform pH value, uniform feeding speed and the like. The method comprises the following specific steps:
(1) Preparing 50L of reaction base solution, wherein the pH value of the reaction base solution is 11.7, the ammonia concentration is 0.4mol/L, heating the reaction base solution in a jacket water bath to 60 ℃, and introducing nitrogen to carry out oxygen removal treatment on the reaction base solution. The method comprises the steps of simultaneously injecting a nickel-cobalt-manganese sulfate solution, ammonia water and sodium hydroxide into a 100L reaction kettle, setting a stirring rotation speed to be 1000rpm, setting a reaction system temperature to be 60 ℃, setting an ammonia concentration to be 0.4mol/L and setting a pH value to be 11.7, wherein the molar ratio of nickel, cobalt and manganese in a mixed salt solution is 6.
(2) The metal salt solution, the sodium hydroxide solution and the ammonia water are injected into the reaction kettle through the electric diaphragm pump, the flow of the metal salt solution is 2L/h, the flow of the raw material liquid ammonia is 0.3L/h, and the pH value is controlled to be 11.7 by automatically adjusting the flow of the sodium hydroxide solution through the feedback control system.
(3) The reaction is started to be a nucleation stage, the pH is kept to be 11.7, the rotating speed of a stirring paddle is 1000rpm, the flow rate of the metal salt solution is 2L/h, the particle size distribution is tested once every 1 hour by using a laser particle sizer, after the volume particle size distribution D50 reaches 3 micrometers, the reaction enters a particle growth stage, the pH is kept at 11.7, the stirring rotating speed is kept at 1000rpm, and the feeding speed of the metal salt solution is 2L/h; when the particle volume and particle size distribution D50 reaches 4 mu m, stopping feeding the metal salt solution, the ammonia water and the sodium hydroxide, opening a liquid outlet of the reaction kettle, and putting the kettle into the reaction kettleDischarging 1/2 volume of slurry into a concentration kettle 1, discharging clear liquid through concentration operation, pumping the concentrated slurry into a washing kettle by using a pneumatic diaphragm pump, washing for 20min by using hot alkali to remove SO on the surfaces of particles 4 2- At the moment, the residual slurry in the reaction kettle is discharged into a concentration kettle 1 for concentration operation, the slurry is pumped into a concentration kettle 2 by using a pneumatic diaphragm pump after the hot alkali washing in a washing kettle is finished, and the slurry is pumped into the reaction kettle again after the redundant sodium hydroxide solution is removed; through twice concentration, alkali washing and concentration operations, the volume of slurry in the reaction kettle is reduced, 0.4mol/L ammonia water is injected into the reaction kettle through a liquid supplementing hole, meanwhile, the pH value in the kettle is controlled to be maintained at 11.7 by a pH automatic adjusting feedback system, when the volume of the slurry in the kettle reaches 50L of the effective volume of the reaction kettle, the liquid supplementing is stopped, the feeding of a metal salt solution, a sodium hydroxide solution and the ammonia water is restarted, and the small spherical particles returned to the reaction kettle continue to grow up through coprecipitation reaction.
(4) The concentration, alkali washing and concentration operations are carried out once when the particle volume particle size distribution D50 is increased by 2 mu m.
(5) And after the particle size reaches 10 mu m, ageing the slurry in the reaction kettle for 4 hours, then putting the slurry into a hot alkali washing kettle for alkali washing, then putting the slurry into a centrifuge for washing by using pure water, and demagnetizing, drying and sieving the washed material to obtain the product.
Comparative example 6:
the other operations were exactly the same as those of example 1 except that the hot alkaline washing with 2mol/L of 50 ℃ sodium hydroxide in step (3) was changed to the hot pure water washing at 50 ℃.
The S contents of the ternary precursor materials prepared in examples 1 to 2 and comparative examples 1 to 6 were measured by ICP, XRD, archimedes buoyancy method, and the results are shown in table 1. Comparative example 4 no product with a D50 of 10 μm was synthesized due to too long caustic wash time and no correlation test was performed.
Table 1 example and comparative example precursor S impurity content grain size
According toICP test results it can be seen that example 1 reduces SO in solution by displacing the solution in the autoclave 4 2- Content of SO on the surface of the particles washed with hot alkali 4 2- Effectively removes sulfur impurities in the precursor. From XRD, although the S impurity content of comparative example 3 is lower, the washing is too frequent, the continuity of crystal growth is damaged, the crystallinity is poor, and qualified products cannot be synthesized. This is also confirmed from the XRD pattern of fig. 2, and the peak intensity of comparative example 3 is significantly weaker than that of example 1, indicating that comparative example 3 has poor crystallinity.
The grain sizes of the precursor in the 001 direction and the 100 direction are calculated by XRD, and the thickness of the grain in the two directions is increased after the content of the S impurity in the precursor is reduced.
The real density of the precursor is further detected by adopting an Archimedes buoyancy method, as shown in Table 1, the real density of the precursor prepared in the embodiment of the invention is superior to that of a comparative example, particularly the real density of the embodiment 1 is the highest, which shows that the real density of the precursor is effectively improved after the S impurity content is reduced by adopting the method disclosed by the invention, so that the compaction density of the battery is favorably improved, and the capacity of the battery is improved.
As shown in fig. 3, SEM pictures of the precursor product in comparative example 1 (right drawing) and comparative example 5 (left drawing) show that the process method of example 1, which employs a nucleation stage with a high reaction pH value, a high stirring rotation speed and a low salt solution feeding speed, reduces the reaction pH, reduces the stirring rotation speed and increases the salt feeding speed, effectively enhances the dispersibility of the pellet particles in the nucleation stage, improves the sphericity and morphology of the product, and is helpful for improving the product quality.
In order to further verify the electrochemical performance of the ternary precursor material, the ternary precursor positive electrode materials obtained in examples 1,2 and 4 and comparative example 1 are assembled into a button cell, and the assembling steps are as follows: according to the positive electrode material: PVDF =8, 1, uniformly ground, and uniformly coated on an aluminum foil current collector, and placed in a vacuum oven to be dried at a temperature of 80 ℃Drying for 12h to prepare a positive plate, cutting the positive plate into a round shape with the size of a button battery by using a punching machine, wherein the electrolyte adopts 1mol/L LiPF 6 The solution of EC/DEC/DMC =1, clegard 2400 type separator was used for the separator, and lithium sheet was used for the negative electrode, and the assembly of the coin cell was completed in a glove box.
Electrochemical performance test conditions: and (3) carrying out constant current charge and discharge tests on the button cell under the constant temperature condition of 25 ℃, wherein the voltage range is 2.8-4.3V, carrying out the charge and discharge performance test of the first 3 periods under the condition of 0.1C, adopting the charge and discharge multiplying power of 0.3C after the 3 rd time, and recording the charge and discharge specific capacity and the first effect after the first time and 50 times of circulation. Specific electrochemical performance test data are shown in table 2.
TABLE 2 electrochemical Performance data
As can be seen from the comparison of the electrochemical performance data of the examples 1 and 2 and the comparative example 5, the precursor synthesized in the nucleation stage and the growth stage has more excellent electrochemical performance because the particles are more compact and the compaction density of the battery pole piece is improved.
In conclusion, the invention adopts the key control means of controlling the conditions of the nucleation stage and the growth stage and replenishing the new complexing agent liquid after the slurry is subjected to alkaline washing and returns to the reaction kettle, so as to obtain the ternary precursor material with low S impurity content and good crystallization property, and the lithium ion battery prepared by the anode of the ternary precursor material has better capacity and cycle performance.
While the present invention has been described in detail with reference to the preferred embodiments, it should be understood that the above description should not be taken as limiting the invention. It will be appreciated by those skilled in the art that modifications or adaptations to the invention may be made in light of the teachings of the present specification. Such modifications or adaptations are intended to be within the scope of the present invention as defined in the claims.
Claims (14)
1. A preparation method of a nickel-cobalt-manganese ternary precursor for reducing sulfur content in a continuous production process comprises the steps of taking sulfates of nickel, cobalt and manganese, alkali and a complexing agent as raw materials, synthesizing the ternary precursor to a target granularity in a reaction kettle through coprecipitation, and aging, washing, drying and sieving to obtain a ternary precursor material, and is characterized in that the synthesis of the precursor is divided into two stages:
1) A nucleation stage: forming a large amount of micro particles by adopting high pH, high stirring speed and low feeding speed; the high pH is 11.5-12.0, the high stirring speed is 800-1500rpm, and the low feeding speed is 1-3L/h;
2) And (3) growth stage: the particles grow up rapidly by adopting low pH, low stirring speed and high feeding speed; the low pH is 10.0-11.5, the low stirring speed is 200-800rpm, and the high feeding speed is 3-8L/h;
detecting the particle size distribution every 1 hour in the growth stage, and performing hot alkali washing operation every 2-3 mu m according to the particle volume particle size distribution D50 until the particles grow to the target particle size; the alkali washing operation comprises the following steps:
s1, stopping feeding of sulfate, alkali and a complexing agent, feeding the slurry discharged from the reaction kettle into a thickener 1 for concentration, discharging clear liquid, improving the solid content of the slurry, and discharging SO in the solution 4 2- ；
S2, feeding the concentrated slurry into a washing kettle, flushing the surface of spherical particles by hot alkali under the stirring action, and discharging SO on the surface of the particles 4 2- Removing;
and S3, pumping the washed slurry into a thickener 2 through a pump, filtering redundant clear liquid of the slurry, pumping the filtered slurry into the reaction kettle again, feeding the slurry into the reaction kettle after concentration, alkali washing and concentration, immediately injecting a complexing agent with the same concentration as the reaction condition into the reaction kettle, and continuously growing the small spherical particles returned to the reaction kettle through a coprecipitation reaction.
2. The method for preparing the nickel-cobalt-manganese ternary precursor with the reduced sulfur content in the continuous production process according to claim 1, wherein the slurry is concentrated, washed with alkali, concentrated and returned to the reaction kettle, then immediately a complexing agent with the same concentration as the reaction condition is injected into the reaction kettle, and meanwhile, the pH value of the reaction is automatically adjusted by a feedback system to maintain stable, and then the slurry is re-fed to enable the pellet particles returned to the reaction kettle to continue to grow.
3. The method for preparing the nickel-cobalt-manganese ternary precursor with reduced sulfur content in the continuous production process according to claim 1, wherein the base in the raw material is selected from any one of NaOH or KOH; the complexing agent is selected from any one or more of ammonia water, urea, ammonium acetate, ammonium sulfate, ammonium carbonate, ammonium chloride and ammonium nitrate.
4. The method for preparing the nickel-cobalt-manganese ternary precursor for reducing the sulfur content in the continuous production process according to claim 1, wherein the alkali in the raw material is NaOH; the complexing agent is ammonia water.
5. The method for preparing the nickel-cobalt-manganese ternary precursor with the reduced sulfur content in the continuous production process according to claim 1, wherein the nucleation stage is finished after the volume particle size distribution D50 of the precursor in the nucleation stage reaches 3 μm.
6. The method for preparing the nickel-cobalt-manganese ternary precursor with reduced sulfur content in the continuous production process according to claim 1, wherein the aging is started after the volume particle size distribution D50 of the precursor in the growth stage reaches 10 μm and the growth stage is finished.
7. The method for preparing the nickel-cobalt-manganese ternary precursor for reducing the sulfur content in the continuous production process according to claim 6, wherein the growth stage comprises a first growth stage and a second growth stage, the pH value of the reaction kettle system in the first growth stage is 11.0-11.5, the stirring speed is 500-800rpm, and the feeding speed of the salt solution is 3-5L/h; and (3) starting alkali washing operation after entering the first stage, and ending the first growth stage after the volume particle size distribution D50 of the precursor reaches 7 mu m.
8. The method for preparing the nickel-cobalt-manganese ternary precursor with the sulfur content reduced in the continuous production process according to claim 7, wherein after the first growth stage is finished, the reaction enters a second growth stage, the alkali washing operation is continued, the pH value of a reaction kettle system is 10.0-11.0, the stirring rotation speed is 200-500rpm, and the feeding speed of a salt solution is 5-8L/h; and after the volume particle size distribution D50 of the precursor reaches 10 mu m, finishing the growth stage and beginning to age.
9. The method for preparing the nickel-cobalt-manganese ternary precursor with the reduced sulfur content in the continuous production process according to claim 1, wherein the hot alkali is selected from any one of sodium hydroxide, potassium hydroxide and barium hydroxide; the temperature of the hot alkali is 40-90 ℃; the concentration of the sodium hydroxide solution is 1mol/L-10 mol/L.
10. The method for preparing the nickel-cobalt-manganese ternary precursor for reducing the sulfur content in the continuous production process according to claim 1, wherein the hot alkali is selected from sodium hydroxide; the temperature of the hot alkali is 50-60 ℃; the concentration of the sodium hydroxide solution is 2-4 mol/L.
11. The method for preparing the nickel-cobalt-manganese ternary precursor for reducing the sulfur content in the continuous production process according to claim 1, wherein the reaction base solution comprising alkali and a complexing agent has a pH value of 11-13, an ammonia concentration of 0.2-0.6mol/L and a reaction temperature of 40-70 ℃.
12. The method for preparing the nickel-cobalt-manganese ternary precursor for reducing the sulfur content in the continuous production process according to claim 1, wherein the pH value of the reaction base solution is 11.2-11.9, the ammonia concentration is 0.25-0.5mol/L, and the reaction temperature is 50-60 ℃.
13. The method for preparing the nickel-cobalt-manganese ternary precursor with the reduced sulfur content in the continuous production process according to claim 1, wherein the thickener is a device with a stirring function, and can discharge clear slurry liquid, leave solid phase in a kettle and improve the solid content of the slurry.
14. The method for preparing the nickel-cobalt-manganese ternary precursor with reduced sulfur content in the continuous production process according to any one of claims 1 to 13, wherein the chemical formula of the nickel-cobalt-manganese ternary precursor is Ni x Co y Mn z (OH) 2 Wherein x + y + z =1 and 0.20 < x < 0.90,0.05 < y < 0.40,0.05 < z < 0.40.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011352509.4A CN112582605B (en) | 2020-11-27 | 2020-11-27 | Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011352509.4A CN112582605B (en) | 2020-11-27 | 2020-11-27 | Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112582605A CN112582605A (en) | 2021-03-30 |
| CN112582605B true CN112582605B (en) | 2022-11-04 |
Family
ID=75123774
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011352509.4A Active CN112582605B (en) | 2020-11-27 | 2020-11-27 | Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112582605B (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113451565B (en) * | 2021-05-06 | 2024-02-13 | 福建常青新能源科技有限公司 | Production process of high-tap high-sphericity internal radial ternary precursor |
| CN113321245B (en) * | 2021-05-25 | 2023-05-05 | 华友新能源科技（衢州）有限公司 | Nickel-cobalt-manganese hydroxide and preparation method thereof |
| CN115520906A (en) * | 2021-06-24 | 2022-12-27 | 华友新能源科技（衢州）有限公司 | Narrow-distribution large-particle nickel-cobalt-manganese hydroxide and preparation method thereof |
| CN113582247B (en) * | 2021-06-30 | 2023-07-14 | 南通金通储能动力新材料有限公司 | Method for preparing high-nickel quaternary precursor |
| CN113896251A (en) * | 2021-09-02 | 2022-01-07 | 荆门市格林美新材料有限公司 | Preparation device and preparation method of high-tap-density ternary precursor material |
| CN114014379B (en) * | 2021-10-22 | 2022-08-26 | 广东佳纳能源科技有限公司 | Ternary precursor material, continuous preparation method, ternary material and secondary battery |
| CN114956201A (en) * | 2022-04-24 | 2022-08-30 | 南通金通储能动力新材料有限公司 | Large-particle ternary precursor and preparation method thereof |
| CN115092973B (en) * | 2022-06-10 | 2024-04-02 | 华友新能源科技（衢州）有限公司 | Positive electrode precursor, continuous preparation method thereof, positive electrode material and secondary battery |
| CN115124090A (en) * | 2022-07-14 | 2022-09-30 | 广东邦普循环科技有限公司 | Preparation method of low-sulfur high-specific-surface-area ternary positive electrode precursor material |
| CN115490273B (en) * | 2022-08-17 | 2023-09-22 | 四川顺应动力电池材料有限公司 | Method for continuously preparing ternary precursor with large specific surface and prepared precursor |
| KR20240037680A (en) * | 2022-09-15 | 2024-03-22 | 주식회사 엘지화학 | Preparing method of precusor for positive electrode active material |
| CN116621234B (en) * | 2023-07-20 | 2023-11-07 | 宜宾光原锂电材料有限公司 | Sodium ion positive electrode material precursor, preparation method and positive electrode material |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103943847B (en) * | 2014-04-21 | 2016-06-29 | 中信国安盟固利电源技术有限公司 | A kind of method preparing nickel-cobalt-manganese ternary material precursor |
| JP6895105B2 (en) * | 2016-08-01 | 2021-06-30 | 住友金属鉱山株式会社 | A method for producing nickel-manganese composite hydroxide particles and a method for producing a positive electrode active material for a non-aqueous electrolyte secondary battery. |
| KR102086536B1 (en) * | 2017-02-06 | 2020-03-10 | 주식회사 엘지화학 | Method for preparing positive electrode active material precursor and positive electrode active material for lithium secondary battery |
| CN107611383B (en) * | 2017-08-25 | 2020-05-19 | 浙江华友钴业股份有限公司 | Preparation method of nickel-cobalt-manganese ternary precursor with low sulfur and high tap density |
| CN108417826A (en) * | 2018-02-02 | 2018-08-17 | 昆明理工大学 | A kind of preparation method of the nickel cobalt lithium aluminate cathode material of three graded elemental of nickel cobalt aluminium distribution |
| CN108767218A (en) * | 2018-05-21 | 2018-11-06 | 金川集团股份有限公司 | A kind of post-processing approach that battery is prepared with nickel cobalt aluminium hydroxide |
| JP7205114B2 (en) * | 2018-08-30 | 2023-01-17 | 住友金属鉱山株式会社 | Method for producing transition metal composite hydroxide and method for producing positive electrode active material for lithium ion secondary battery |
| CN110817975B (en) * | 2019-09-19 | 2020-08-07 | 宜宾光原锂电材料有限公司 | Method for reducing sulfur content of ternary precursor |
| CN111807421A (en) * | 2020-06-23 | 2020-10-23 | 湖南邦普循环科技有限公司 | Method for reducing sulfur content of precursor of nickel-cobalt-manganese ternary positive electrode material |
| CN111732132B (en) * | 2020-07-06 | 2020-11-27 | 金驰能源材料有限公司 | Nickel-cobalt-manganese core-shell structure precursor, preparation method thereof and positive electrode material |
| CN111874958B (en) * | 2020-08-10 | 2021-04-23 | 浙江帕瓦新能源股份有限公司 | Wet synthesis method of NCMA high-nickel quaternary precursor |
-
2020
- 2020-11-27 CN CN202011352509.4A patent/CN112582605B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112582605A (en) | 2021-03-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112582605B (en) | Preparation method of nickel-cobalt-manganese ternary precursor for reducing sulfur content in continuous production process | |
| CN108011101B (en) | Preparation method of large-particle-size uniformly-aluminum-doped cobaltosic oxide | |
| CN110048118B (en) | High-nickel cobalt lithium manganate single crystal precursor, preparation method thereof and high-nickel cobalt lithium manganate single crystal positive electrode material | |
| CN104201368B (en) | Lithium battery ternary material precursor nickel cobalt manganese hydroxide and preparation method thereof | |
| CN112357973A (en) | Preparation method of positive electrode material precursor and prepared positive electrode material precursor | |
| CN112758991B (en) | Preparation method of core-shell structure ternary cathode material precursor | |
| CN112357975A (en) | Preparation method of hollow ternary cathode material precursor and prepared ternary cathode material precursor | |
| CN109422297B (en) | Method for regulating and controlling nucleation in crystallization process of nickel-cobalt-manganese precursor | |
| JPWO2017104688A1 (en) | Positive electrode active material for lithium secondary battery, method of producing precursor of positive electrode active material, method of producing positive electrode active material, positive electrode for lithium secondary battery, and lithium secondary battery | |
| CN110611098B (en) | High-radiation and high-tap-density nickel-cobalt lithium aluminate precursor and preparation method thereof | |
| CN110808369B (en) | Preparation method of low-sodium-sulfur nickel-cobalt-aluminum ternary precursor | |
| CN114349068B (en) | Preparation method of large-particle-size nickel-cobalt-aluminum ternary positive electrode material precursor | |
| CN108264096B (en) | Preparation method of high-density small-particle nickel-cobalt-manganese hydroxide | |
| CN104600285A (en) | Method for preparing spherical lithium nickel manganese oxide positive pole material | |
| KR101883406B1 (en) | Positive active material precursor and manufacturing method thereof, positive active material and manufacturing method thereof, lithium rechargeable battery including the same positive active material | |
| CN113206242A (en) | Nickel-cobalt-manganese-aluminum quaternary precursor, positive electrode material and preparation method | |
| CN111807425A (en) | Method for preparing high-performance ternary positive electrode material of lithium ion battery under low ammonia concentration | |
| CN111661879B (en) | Nickel-cobalt-tungsten oxide, preparation method thereof and lithium ion battery | |
| JP7170046B2 (en) | Cathode active material for lithium secondary battery, manufacturing method thereof, and lithium secondary battery containing said cathode active material | |
| CN107342402B (en) | Preparation of LiNi1/3Co1/3Mn1/3O2Method for preparing ternary cathode material | |
| CN110752366A (en) | Nickel-cobalt-aluminum hydroxide precursor, preparation method thereof, positive electrode material and battery | |
| CN113258062B (en) | Ternary precursor with radial spherical-roof cone structure, positive electrode material and preparation method | |
| CN112366308B (en) | Method for rapidly synthesizing nickel-cobalt-manganese positive electrode material precursor | |
| CN112531155B (en) | Preparation method of positive electrode material precursor and preparation method of positive electrode material | |
| CN114057239A (en) | Preparation method of alkaline water-washing-containing high-nickel ternary precursor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |