High-tap-density large-specific-surface-area small-particle ternary precursor and continuous process preparation method thereof
Through the continuous process preparation method, the solid content is controlled by using the reactor synthesis process and the enrichment device, the existing ternary precursor preparation method is solved, and the efficient mass production and high performance indicators of the ternary precursor are achieved.
Patent Information
- Application Number
- CN202411937996.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-26
- Publication Date
- 2025-03-14
AI Technical Summary
The existing ternary precursor preparation method is complex in operation, resulting in high production costs and is difficult to meet the market's demand for high energy density, safety performance and low cost.
The continuous process preparation method is adopted, and the solid content is controlled through the reactor synthesis process and the enrichment device, the particle size index is monitored, and the preparation of the ternary precursor of the small particles of high-vibration large-specific table is realized.
It simplifies production operations, reduces production costs, and achieves efficient mass production. The particle size and structural indicators of the product are within a stable range, meeting the market's demand for high-performance materials.
Smart Images
Figure CN119612624A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lithium battery materials, and in particular to a ternary precursor with high tap density, large specific surface area and small particles and a continuous process preparation method thereof. Background Art
[0002] The new energy market has reached an explosive turning point, and the penetration rate of electric vehicles continues to increase. Producing batteries with higher energy density, higher safety performance and lower cost has become the key to "breaking the situation". As the mainstream choice in the mid-to-high-end electric vehicle market, ternary batteries have huge market demand. If we want to meet higher market expectations, we need to upgrade their material technology and innovate their processes.
[0003] 65% of the performance of ternary materials is determined by the precursor. The main reason is that the quality of the precursor (morphology, particle size, particle size distribution, specific surface area, impurity content, tap density, etc.) directly determines the physical and chemical indicators of the final sintered product. Ternary positive electrode materials are gradually developing towards high specific capacity, high compaction, high voltage and low cost. In this process, it is very important to rationally design the structure of the material. Different structural designs can effectively solve the corresponding problems. The single crystal series ternary precursor specification requirements are that the particle size is generally 2.0~6.0um, which meets the high tap density and high specific surface indicators. In the continuous production process, the flow indicators of the previous and subsequent batches remain stable to achieve the quality target. The coarseness of the primary particles, the sphericity of the secondary particles, and the pore structure of the particles need to be adjusted during the preparation process. It is difficult to produce precursors that meet these indicators at the same time. Summary of the invention
[0004] The present invention provides a highly tapped, large specific surface area, small particle ternary precursor and a continuous process preparation method thereof, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problem that the existing preparation method of the ternary precursor is complicated in operation and results in high production cost.
[0005] To solve the above problems, one of the technical solutions of the present invention is achieved in the following way: a continuous process preparation method of a ternary precursor with high tap density, large specific surface area and small particles, comprising the following steps: S1, preparing a preliminary solution, wherein the preliminary solution includes an alkaline precipitant solution, a metal complexing agent solution and a nickel-cobalt-manganese mixed salt solution; S2, continuously adding the nickel-cobalt-manganese mixed salt solution into the reactor, and continuously adding the alkaline precipitant and the metal complexing agent to react, stirring is continuously turned on during the reaction process, and nitrogen or an inert gas is introduced into the reactor; S3, the overflow liquid in step S2 flows to the concentration device, and the concentration device controls the solid content of the reaction system to 12-20%. When the particle size grows to 2.0-5.0um, the liquid feeding into the reactor is stopped, and the reaction atmosphere in the reactor is switched to an oxidizing atmosphere. At the same time, the additive is continuously introduced for co-precipitation reaction, stirring is started, and the alkaline precipitant is continuously added; S4, monitor the particle size in the reactor every hour. When the D50 of the reactor is reduced by 0.5-1um and the Span meets 1.0-1.6, the nucleation stage of the ternary precursor is completed; S5, after the nucleation is completed, the oxidizing gas and the additive solution are continuously introduced into the reactor, and the concentration device maintains the solid content of the system at 10%-40%. After the particle size in the reactor is monitored every hour to the target particle size, the overflow is sent to the aging reactor; S6, the product overflowing into the aging kettle is filtered, washed and dried to obtain a single crystal ternary precursor.
[0006] In the above step S1, the total molar concentration of nickel, cobalt and manganese in the mixed salt solution is 1.0-2.5 mol / L.
[0007] In the above step S2, the alkaline precipitant is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 20% to 40%; the metal complexing agent is at least one of N-hydroxyethylethylenediamine-N,N′,N′-triacetic acid, diethylamine acetic acid and ethylenediaminetetraacetic acid with a molar concentration of 2 to 4 mol / L.
[0008] In the above step S2, the nickel-cobalt-manganese mixed salt solution is continuously added to the reactor at a flow rate of 15-200 L / h through a metering pump; the pH value in the reactor is stabilized at 11.40-11.90 by adding an alkaline precipitant, and the reaction temperature is maintained at 45-80°C.
[0009] In the above step S3, the additive is one or two of diaminetetraacetic acid disodium salt, sodium succinate, sodium pentahydroxycaproate, sodium citrate, disodium citrate, and sodium dodecyl sulfate; the mass percentage of the additive is 0.05-0.35%.
[0010] In the above step S3, the pH value in the reactor is stabilized at 11.40-11.90, the reaction temperature is controlled at 45-80°C, and the rotation speed of the reactor is 350-700 r / min.
[0011] The second technical solution of the present invention is achieved by the following method: a high-tap-compacted, large-specific-weight, small-particle ternary precursor, which is prepared using a continuous process preparation method for a high-tap-compacted, large-specific-weight, small-particle ternary precursor.
[0012] Compared with the prior art, the present invention has the following advantages: 1. The preparation method of the present invention adopts a reactor synthesis process, a concentration device controls the solid content of the system, continuous feeding provides a reaction equilibrium environment, continuous overflow aging kettle collection, and continuous finished product discharge. Therefore, the present invention adopts a continuous method to produce and prepare small particles with high compaction and large specific surface area. Compared with the intermittent method, the production operation is simple, the production cost is low, it is easy to mass produce, and the cost is reduced.
[0013] 2. The present invention adds a nickel-cobalt-manganese mixed salt solution and a complexing agent into a reactor, uses a precipitant to adjust the pH to 11.40-11.90, and ends the reactor to a particle size of 2.0-5.0 um. Then, an oxidizing atmosphere and an additive solution are continuously introduced, and a concentration device controls the solid content to 10-40%. An alkaline precipitant is used to adjust the pH in the reactor to within the range of 11.40-11.90. The particle size in the reactor is monitored every hour, and the D50 difference is within the range of 0.5-1.0 um. The reactor is controlled to reach a balanced state, and the output finished product is continuously collected in the overflow aging reactor within the particle size index range. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.
[0015] Figure 1 This is an electron microscope image of the precursor after the coprecipitation reaction in Example 3 of the present invention is completed.
[0016] Figure 2 This is an electron microscope image of the precursor obtained after being treated by the method of Example 4 of the present invention.
[0017] Figure 3 This is an electron microscope image of the precursor after the coprecipitation reaction in Example 5 of the present invention is completed. DETAILED DESCRIPTION
[0018] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.
[0019] Example 1: The present invention discloses a continuous process preparation method of a ternary precursor with high tap density, large specific surface area and small particles, comprising the following steps: S1, preparing a preliminary solution, wherein the preliminary solution includes an alkaline precipitant solution, a metal complexing agent solution and a nickel-cobalt-manganese mixed salt solution; S2, continuously adding the nickel-cobalt-manganese mixed salt solution into the reactor, and continuously adding the alkaline precipitant and the metal complexing agent to react, stirring is continuously turned on during the reaction process, and nitrogen or an inert gas is introduced into the reactor; S3, the overflow liquid in step S2 flows to the concentration device, and the concentration device controls the solid content of the reaction system to 12-20%. When the particle size grows to 2.0-5.0um, the liquid feeding into the reactor is stopped, and the reaction atmosphere in the reactor is switched to an oxidizing atmosphere. At the same time, the additive is continuously introduced for co-precipitation reaction, stirring is started, and the alkaline precipitant is continuously added; S4, monitor the particle size in the reactor every hour. When the D50 of the reactor is reduced by 0.5-1um and the Span meets 1.0-1.6, the nucleation stage of the ternary precursor is completed; S5, after the nucleation is completed, the oxidizing gas and the additive solution are continuously introduced into the reactor, and the concentration device maintains the solid content of the system at 10%-40%. After the particle size in the reactor is monitored every hour to the target particle size, the overflow is sent to the aging reactor; S6, the product overflowing into the aging kettle is filtered, washed and dried to obtain a single crystal ternary precursor.
[0020] Wherein, in step S1, the total molar concentration of nickel, cobalt and manganese in the mixed salt solution is 1.0-2.5 mol / L.
[0021] Wherein, in step S2, the alkaline precipitant is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 20% to 40%; the metal complexing agent is at least one of N-hydroxyethylethylenediamine-N,N′,N′-triacetic acid (HEDTA), diethylamine acetic acid and ethylenediaminetetraacetic acid with a molar concentration of 2 to 4 mol / L.
[0022] In step S2, the nickel-cobalt-manganese mixed salt solution is continuously added to the reactor at a flow rate of 15-200 L / h through a metering pump; the pH value in the reactor is stabilized at 11.40-11.90 by adding an alkaline precipitant, and the reaction temperature is maintained at 45-80°C.
[0023] In step S2, the flow rate of nitrogen or inert gas is 1-3 m 3 / h.
[0024] Among them, in step S3, the additive is one or two of diaminetetraacetic acid disodium salt, sodium succinate, sodium pentahydroxycaproate, sodium citrate, disodium citrate, and sodium dodecyl sulfate; the mass percentage of the additive is 0.05~0.35%.
[0025] Among them, in step S3, the pH value in the reactor is stabilized at 11.40-11.90, the reaction temperature is controlled at 45-80°C, the rotation speed of the reactor is 350-700r / min; and the flow rate of the oxidizing gas is controlled at 5-40%.
[0026] Among them, in step S3, the precipitant is added in the sealed reactor, and the pH of the entire reaction system is maintained at 11.40-11.90. The impurity S content in the monitoring process is low, washing is easier, and the amount of alkali added for washing and the unit consumption of washing water are reduced. It is suitable for large-scale application and has lower cost.
[0027] In step S5, the oxidizing gas and the additive solution are continuously introduced to keep the reactor in a balanced state.
[0028] The single crystal small particle ternary precursor prepared by the above preparation method has a D50 of 2.0~5.0um, a particle size interval of 0.95~1.35, and a tap density of 1.45~2.00g / cm 3 , with a specific surface area of 8~25m 2 / g; the single crystal small particle ternary precursor has good consistency in size, full small particles, and the thickness of the primary particle is 10-100um.
[0029] In summary, the preparation method of the present invention adopts a reactor synthesis process, a concentration device controls the solid content of the system, continuous feeding provides a reaction equilibrium environment, continuous overflow aging kettle collection, and continuous finished product discharge. Therefore, the present invention adopts a continuous method to produce and prepare small particles with high compaction and large specific surface area. Compared with the intermittent method, the production operation is simple, the production cost is low, it is easy to mass produce, and the cost is reduced.
[0030] In addition, the present invention adds a nickel-cobalt-manganese mixed salt solution and a complexing agent into a reaction kettle, uses a precipitant to adjust the pH to 11.40-11.90, and ends the reaction kettle to a particle size of 2.0-5.0 um. Then, an oxidizing atmosphere and an additive solution are continuously introduced, a concentration device controls the solid content to 10-40%, an alkaline precipitant is used to adjust the pH in the reaction kettle to be in the range of 11.40-11.90, monitors the particle size in the kettle every hour, and controls the D50 difference to be in the range of 0.5-1.0 um, and reaches a balanced state, and continuously overflows the aging kettle within the particle size index range to collect the output finished product.
[0031] At the same time, the present invention is carried out in a sealed atmosphere with nitrogen or inert gas protection at the initial stage of the reaction, which is beneficial to the initial particle growth and avoids particle agglomeration leading to unstable product indicators. During the nucleation period, oxidizing gas and additives are continuously introduced into the sealed reactor, which is beneficial to opening the internal pores of the precursor, widening the pore volume and pore diameter, and increasing the diffusion rate of lithium ions during the calcination of the positive electrode precursor.
[0032] Example 2: The embodiment of the present invention discloses a ternary precursor with high tap density, large specific surface area and small particles. The ternary precursor is prepared using a continuous process preparation method for a ternary precursor with high tap density, large specific surface area and small particles.
[0033] Example 3: The present invention discloses a continuous process preparation method of a ternary precursor with high tap density, large specific surface area and small particles, comprising the following steps: Step 1, prepare a mixed salt solution with a molar ratio of Ni, Co and Mn of 65:15:20, wherein the total concentration of Ni, Co and Mn in the mixed salt solution is 2.0 mol / L; prepare a sodium hydroxide or potassium hydroxide solution with a mass fraction of 32% as a precipitant; prepare disodium citrate and a complexing agent ethylenediaminetetraacetic acid as a mixed additive solution, wherein the pH of the mixed salt solution is 9.5-10.5.
[0034] Step 2: Add the above sodium hydroxide or potassium hydroxide solution, pure water and complexing precipitant into a closed reactor to prepare a bottom liquid, wherein the concentration of the complexing agent in the bottom liquid is 0.15 mol / L, the pH value is 11.40-11.90, and the temperature is 60° C. The volume of the bottom liquid in the reactor is 50% of the volume of the reactor.
[0035] Step 3: Keep the stirring of the reactor on and introduce nitrogen at a flow rate of 1.5m 3 / h, the mixed salt solution in step one is continuously added into the reactor at a flow rate of 5L / min and the precipitant is adjusted by the actual pH value to carry out a co-precipitation reaction, the process pH value of the No. 1 reactor is maintained at 11.40-11.90, the reaction temperature is maintained at 60°C, the stirring speed of the reactor is maintained at 350-700r / min, the concentration of the complexing agent in the slurry in the reactor is 0.20mol / L, and the concentration of the mixed salt solution in the slurry in the reactor is 0.04%.
[0036] Step 4: The overflow liquid of the reactor flows to the concentration device. When the particle size D501 of the reactor grows to 2-5 um, the liquid feeding is suspended. Then the inert gas in the reactor is turned off, and the oxidizing gas is continuously introduced into the system. The flow rate of the oxidizing gas is controlled at 5-40%. At the same time, the additive solution is continuously added to continue the coprecipitation reaction. The solid content of the reactor is controlled at 15-40% by the concentration device.
[0037] Step 5: The coprecipitated product in step 4 is filtered, washed and dried to obtain a single crystal ternary precursor. The chemical formula of the product is Ni 0.65 Co 0.15 Mn 0.20 (OH) 2 , D50 is 3.87um, particle size distance is 1.147 Among them, in step 1, the pH is adjusted to 11.40-11.90 by adding a precipitant, so that the particle size D502 in the reactor grows to a difference of 0.5-1 um from D501, and the span in the reactor is in the range of 1.0-1.6.
[0038] Among them, the precursor obtained after the reaction of Example 3 is completed, and the relevant data are shown in Table 1.
[0039] Example 4: The embodiment of the present invention discloses a method for preparing a ternary precursor. The difference between this embodiment and Example 3 is that no additive solution is added in step 4, and the other reaction conditions and parameters are the same as those in Example 3. The obtained precursor is washed and dried. The relevant data are shown in Table 1.
[0040] Example 5: The embodiment of the present invention discloses a method for preparing a ternary precursor. The difference between this embodiment and Example 3 is that the oxidizing gas is not switched in step 4, and the other reaction conditions and parameters are the same as those in Example 3. The precursor is washed and dried, and the relevant data are shown in Table 1.
[0041] Comparing the data of the examples in Table 1, it can be seen that, under the same other conditions, the addition of the mixed additive solution and the oxidizing atmosphere has no effect on the particle size D502 and diameter distance of the final product. However, when the oxidizing atmosphere is introduced into the reactor, the impurity S content level of the final product will increase.
[0042] in, Figure 1 , Figure 2 , Figure 3 The Ni prepared in Example 3, Example 4 and Example 5 are respectively 0.65 Co 0.15 Mn 0.20 (OH) 2 The electron microscope image of the secondary particles shows that adding an appropriate amount of additives during the synthesis process can effectively refine the primary particles and grow them radially to make the product have a better crystal structure, reduce the S content in the process, and the oxidizing atmosphere can increase the porosity inside the precursor.
Claims
1. A continuous process preparation method for a high-tap-compacted, large-specific-surface-size, small-particle ternary precursor, characterized in that: The following steps are involved: S1, preparing a preliminary solution, wherein the preliminary solution includes an alkaline precipitant solution, a metal complexing agent solution and a nickel-cobalt-manganese mixed salt solution; S2, continuously adding the nickel-cobalt-manganese mixed salt solution into the reactor, and continuously adding the alkaline precipitant and the metal complexing agent to react, stirring is continuously turned on during the reaction process, and nitrogen or an inert gas is introduced into the reactor; S3, the overflow liquid in step S2 flows to the concentration device, and the concentration device controls the solid content of the reaction system to 12-20%. When the particle size grows to 2.0-5.0um, the liquid feeding into the reactor is stopped, and the reaction atmosphere in the reactor is switched to an oxidizing atmosphere. At the same time, the additive is continuously introduced for co-precipitation reaction, stirring is started, and the alkaline precipitant is continuously added; S4, monitor the particle size in the reactor every hour. When the D50 of the reactor is reduced by 0.5-1um and the Span meets 1.0-1.6, the nucleation stage of the ternary precursor is completed; S5, after the nucleation is completed, the oxidizing gas and the additive solution are continuously introduced into the reactor, and the concentration device maintains the solid content of the system at 10%-40%. After the particle size in the reactor is monitored every hour to the target particle size, the overflow is sent to the aging reactor; S6, the product overflowing into the aging kettle is filtered, washed and dried to obtain a single crystal ternary precursor.
2. The continuous process preparation method of the high-tap-compacted, large-specific-surface-rate small-particle ternary precursor according to claim 1 is characterized in that: In step S1, the total molar concentration of nickel, cobalt and manganese in the mixed salt solution is 1.0-2.5 mol / L.
3. The continuous process preparation method of the high-tap-compacted, large-specific-surface-rate small-particle ternary precursor according to claim 1 is characterized in that: In step S2, the alkaline precipitant is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 20% to 40%; the metal complexing agent is at least one of N-hydroxyethylethylenediamine-N,N′,N′-triacetic acid, diethylamine acetic acid and ethylenediaminetetraacetic acid with a molar concentration of 2 to 4 mol / L.
4. The continuous process preparation method of the high-tap-compacted, large-specific-surface-rate small-particle ternary precursor according to claim 1 is characterized in that: In the step S2, the nickel-cobalt-manganese mixed salt solution is continuously added to the reactor at a flow rate of 15-200 L / h through a metering pump; the pH value in the reactor is stabilized at 11.40-11.90 by adding an alkaline precipitant, and the reaction temperature is maintained at 45-80°C.
5. The continuous process preparation method of the high-tap-compacted, large-specific-surface-rate, small-particle ternary precursor according to claim 1, characterized in that: In step S3, the additive is one or two of diaminetetraacetic acid disodium salt, sodium succinate, sodium pentahydroxycaproate, sodium citrate, disodium citrate, and sodium dodecyl sulfate; and the mass percentage of the additive is 0.05-0.35%.
6. The continuous process preparation method of the high-tap-compacted, large-specific-surface-rate, small-particle ternary precursor according to claim 1, characterized in that: In step S3, the pH value in the reactor is stabilized at 11.40-11.90, the reaction temperature is controlled at 45-80° C., and the rotation speed of the reactor is 350-700 r / min.
7. A ternary precursor with high tap density, large specific surface area and small particles, characterized in that: The ternary precursor is prepared by the continuous process preparation method of the high-tap-compacted, large-specific-surface-size, small-particle ternary precursor according to any one of claims 1 to 6.