A high-sphericity ultra-high-nickel ternary precursor, a preparation method and application thereof

Abstract

The application discloses a kind of high sphericity ultra-high nickel ternary precursors and its preparation method and application.The method disclosed in the application innovatively controls the stirring speed to be stepped down with the increase of coprecipitation reaction time during coprecipitation reaction, and the stirring speed is controlled to be reduced by 5-20% when the reaction time is increased by 10-20h.At the same time, it is also limited that when the product particle D50 reaches 7-9 μm, the overflow is started, when the product particle D50 reaches 11-13 μm, the overflow is closed and the product system is obtained when the product particle size reaches 15-20 μm, and the feeding is stopped.And preferably, the solid content of the obtained product system is controlled to be 200-400g / L.The sphericity of the product particle is further improved, and the high sphericity ultra-high nickel ternary precursor without crack ball and small particle is finally prepared.The uniformity of the subsequent positive electrode material sintering is further improved, and the battery made of the same has better electrochemical performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of ternary precursors, and in particular relates to a high-sphericity ultra-high nickel ternary precursor and a preparation method and application thereof. Background Art

[0002] As the share of lithium-ion batteries in 3C equipment and new energy vehicles continues to grow, higher requirements are being placed on the production technology of lithium-ion power batteries and ternary power battery precursors. The ternary material lithium nickel cobalt manganese oxide combines the advantages of high capacity, good cycle performance, and high safety performance by combining nickel, cobalt, and manganese metal elements. Currently, ternary materials have become one of the mainstream battery materials in the lithium battery market. The energy density of lithium-ion batteries mainly depends on the discharge capacity of the positive electrode material, so improving the discharge capacity of the positive electrode material is the key to improving energy density. The electrode material currently used in electric vehicle power batteries is mainly lithium nickel cobalt manganese oxide ternary material. The cycle performance of ternary materials is not only related to their composition structure, but also has a certain correlation with the morphology of the ternary precursor. Sphericity is a key dimension in evaluating precursors. High sphericity can improve the tap density, rate performance, and cycle performance of the positive electrode material. Reaction stirring intensity is an effective means to improve the sphericity of large particle precursors (D50: 10-20μm), but it is often difficult to simultaneously achieve high sphericity and small particles and cracked balls: if the stirring intensity is too low, the particles are prone to agglomeration and the sphericity is poor; if the stirring intensity is too high, the particle size growth rate is slow during the synthesis process, the reaction time is long, the solid content is high, and small particles and cracked balls are easily produced. Summary of the Invention

[0003] To address the challenges of the prior art, the present invention provides a highly spherical, ultra-high nickel ternary precursor, its preparation method, and its application. By adjusting the stirring speed and solid content, a ternary precursor oxide with excellent sphericity, free of cracked spheres and small particles is obtained. The present invention specifically includes the following:

[0004] A method for preparing a high-sphericity ultra-high nickel ternary precursor, during the coprecipitation reaction, the stirring speed is regulated to decrease step by step with the increase of the coprecipitation reaction time, and the stirring speed is controlled to decrease by 5-20% (for example, 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, etc.) for every 10-20h increase in reaction time (for example, 10h, 12h, 14h, 16h, 18h, 20h, etc.); at the same time, when the D50 of the product particles reaches 7-9μm (for example, 7μm, 7.2μm, 7.5μm), the stirring speed is controlled to decrease step by step with the increase of the coprecipitation reaction time. m, 7.8 μm, 8 μm, 8.5 μm, 8.8 μm, 9 μm, etc.), the reaction starts to overflow, when the product particles D50 reaches 11-13 μm (for example, 11 μm, 11.5 μm, 12 μm, 12.2 μm, 12.4 μm, 12.6 μm, 12.8 μm, etc.), the overflow is closed and the concentration is re-concentrated, when the particle size of the product particles reaches 15-20 μm (for example, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc.), the feeding is stopped to obtain a product system.

[0005] Preferably, the method for preparing the high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0006] (1) Liquid preparation: prepare ternary solution, liquid alkali solution, ammonia solution and base solution;

[0007] (2) Reaction: Add the ternary solution, liquid alkali solution, and ammonia solution to the base liquid, and perform a coprecipitation reaction while stirring;

[0008] (3) Particle growth: During the coprecipitation reaction, the stirring speed is regulated to decrease step by step with the increase of the coprecipitation reaction time. For every 10-20h increase in reaction time (e.g., 10h, 12h, 14h, 16h, 18h, 20h, etc.), the stirring speed is controlled to decrease by 5-20% (e.g., 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, etc.); At the same time, when the D50 of the product particles reaches 7-9μm (e.g., 7μm, 7.2μm, 7.5μm, 7.8μm), the stirring speed is controlled to decrease by 5-20% (e.g., 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, etc.). When the particle size of the product particles reaches 15-20 μm (for example, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, etc.), the addition of materials is stopped to obtain a product system;

[0009] (4) Post-processing: After post-processing the product system, a high-sphericity ultra-high nickel ternary precursor product is obtained.

[0010] Preferably, the total concentration of nickel salt, cobalt salt and manganese salt in the ternary liquid is 80-120 g / L (for example, 90 g / L, 95 g / L, 100 g / L, 105 g / L, 110 g / L, 115 g / L, etc.), and the molar ratio of nickel, cobalt and manganese is (90-98):(1-5):(1-5), for example, 90:5:5, 92:4:4, 95:2.5:2.5, 96:2:2, etc.

[0011] Preferably, the concentration of the liquid alkali solution is 25%-35% (for example, 26%, 28%, 30%, 32%, 34%, etc.); the concentration of the ammonia solution is 15%-20% (for example, 16%, 17%, 18%, 19%, etc.).

[0012] Preferably, the base liquid includes pure water in a volume ratio of (4-6): (0.2-0.4): (0.01-0.03), a liquid alkali solution with a concentration of 25%-35%, and an ammonia aqueous solution with a concentration of 15%-20%; the ammonia concentration in the base liquid is 8-10 g / L (for example, 8 g / L, 8.5 g / L, 9 g / L, 9.5 g / L, 10 g / L, etc.), and the pH is 10.5-12 (for example, 11, 11.2, 11.6, 11.8, 12, etc.).

[0013] Preferably, the reaction temperature of the coprecipitation reaction is 40-60°C (e.g., 40°C, 45°C, 50°C, 55°C, 60°C, etc.), and the stirring speed is 250-400rpm (e.g., 260rpm, 280rpm, 300rpm, 320rpm, 340rpm, 360rpm, 380rpm, etc.).

[0014] Preferably, in step (2), the flow ratio of the nickel-cobalt-manganese ternary solution, the liquid alkali solution and the ammonia solution when added is (30-50):(10-20):(3-7), for example, 30:10:3, 35:15:4, 40:18:5, 45:12:6, etc.

[0015] Preferably, the solid content of the product system obtained by controlling the step (3) is 200-400 g / L, for example, 200 g / L, 220 g / L, 250 g / L, 280 g / L, 300 g / L, 320 g / L, 350 g / L, 380 g / L, 400 g / L, etc.

[0016] Preferably, the post-treatment in step (4) includes aging, washing, dehydration, drying, calcination, batch mixing, screening, and iron removal in sequence.

[0017] A high-sphericity ultra-high nickel ternary precursor is prepared by adopting the preparation method of the high-sphericity ultra-high nickel ternary precursor disclosed in the present invention.

[0018] The invention discloses an application of a high-sphericity ultra-high nickel ternary precursor in a lithium-ion battery.

[0019] Beneficial effects of the present invention:

[0020] (1) The method disclosed in the present invention innovatively controls the stirring speed to decrease gradually with the increase of the coprecipitation reaction time during the coprecipitation reaction. For every 10-20 hours increase in the reaction time, the stirring speed is controlled to decrease by 5-20%. By precisely controlling the stirring speed, the sphericity of the product particles is improved while the generation of small particles and cracked spheres can be effectively avoided.

[0021] (2) The method disclosed in the present invention not only accurately controls the stirring speed, but also stipulates that: when the product particle D50 reaches 7-9 μm, the reaction begins to overflow, when the product particle D50 reaches 11-13 μm, the overflow is closed and re-concentrated, and when the particle size of the product particles reaches 15-20 μm, the addition of materials is stopped to obtain a product system. And preferably, the solid content of the obtained product system is controlled to be 200-400 g / L. The sphericity of the product particles is further improved, and finally a high-sphericity ultra-high nickel ternary precursor without cracked balls and small particles is prepared. This further improves the uniformity of the subsequent sintering of the positive electrode material, and the battery produced thereby has better electrochemical performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of the process flow of the method disclosed in the present invention;

[0023] Figure 2 This is the SEM image of the high-sphericity ultra-high nickel ternary precursor prepared by the present invention. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1-2 The present invention will be described in detail with specific embodiments. The embodiments shown below do not limit the invention described in the claims. In addition, the entire contents of the configurations shown in the following embodiments are not limited to those necessary for the solution of the invention described in the claims.

[0025] Example 1

[0026] Reference Attachment Figure 1 A method for preparing a high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0027] (1) preparing a ternary solution with a concentration of 80 g / L and a molar ratio of nickel, cobalt and manganese of 90:5:5, a 30% by mass caustic soda solution, and a 16% by mass ammonia solution;

[0028] (2) Towards 8m 3 Add 4.0m3 Pure water, 320L of 16% ammonia solution, and 30L of 30% liquid caustic soda are mixed to form a base solution with a pH of 11.0 and an ammonia concentration of 8.5g / L, and the temperature is raised to 45°C.

[0029] (3) The prepared nickel-cobalt-manganese ternary solution, liquid alkali and ammonia solution were pumped into the reactor at a flow rate of 400 L / h, 148 L / h and 50 L / h respectively through metering pumps. The initial stirring speed was 280 rpm and the temperature was 45 ° C. The particles nucleated and gradually grew. The stirring speed decreased by 20 rpm for every 20 hours of reaction time. At the same time, when the D50 was 8-9 μm, the reaction began to overflow. When it was 11 μm, the overflow was closed and the solution was re-thickened.

[0030] (4) When the particle D50 reaches 20.0 μm, stop feeding and discharge the material into the aging tank;

[0031] (5) The materials are washed, dehydrated, dried, calcined, mixed, screened, and electromagnetically deironed before being packaged into finished products.

[0032] Example 2

[0033] A method for preparing a high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0034] (1) preparing a ternary solution with a concentration of 100 g / L and a molar ratio of nickel, cobalt and manganese of 95:4:1, a 32% by mass caustic soda solution, and an 18% by mass ammonia solution;

[0035] (2) Towards 8m 3 Add 4m 3 Pure water, 280L of 18% ammonia solution, and 20L of 32% liquid caustic soda are added to form a base solution with a pH of 11.3 and an ammonia concentration of 8.0g / L, and the temperature is raised to 55°C.

[0036] (3) The prepared nickel-cobalt-manganese ternary solution, liquid caustic soda and ammonia solution were pumped into the reactor at a flow rate of 300 L / h, 112 L / h and 32 L / h respectively through metering pumps, with a stirring rate of 330 rpm and a temperature of 55 ° C. The particles nucleated and grew. The stirring speed decreased by 30 rpm for every 16 hours of reaction time. At the same time, when the D50 was 7-8 μm, the reaction began to overflow. When it was 12 μm, the overflow was closed and the solution was re-thickened.

[0037] (4) When the particle D50 reaches 18 μm, stop feeding and discharge the material into the aging tank;

[0038] (5) The materials are washed, dehydrated, dried, calcined, mixed, screened, and electromagnetically ironed before being packaged into finished products.

[0039] Example 3

[0040] A method for preparing a high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0041] (1) preparing a ternary solution with a concentration of 120 g / L and a molar ratio of nickel, cobalt and manganese of 98:1:1, a 28% by mass caustic soda solution, and a 17% by mass ammonia solution;

[0042] (2) Towards 8m 3 Add 5m 3 Pure water, 400L of 17% ammonia solution, and 10L of 28% liquid caustic soda are used to prepare a base solution with a pH of 11.5 and an ammonia concentration of 9.0g / L, and the temperature is raised to 60°C.

[0043] (3) The prepared nickel-cobalt-manganese ternary solution, liquid alkali and ammonia solution were pumped into the reactor at a flow rate of 500 L / h, 188 L / h and 65 L / h respectively through metering pumps, with a stirring rate of 380 rpm and a temperature of 60°C. The particles nucleated and grew. The stirring speed decreased by 40 rpm for every 12 hours of reaction time. At the same time, when the D50 was 7-8 μm, the reaction began to overflow, and when it was 13 μm, the overflow was closed and the solution was re-thickened.

[0044] (4) When the particle D50 reaches 15 μm, stop feeding and discharge the material into the aging tank;

[0045] (5) The materials are washed, dehydrated, dried, calcined, mixed, screened, and electromagnetically ironed before being packaged into finished products.

[0046] Example 4

[0047] A method for preparing a high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0048] (1) preparing a ternary solution with a concentration of 90 g / L and a molar percentage of nickel, cobalt and manganese of 92:3:5, a liquid caustic soda solution with a mass fraction of 25%, and an ammonia solution with a mass fraction of 15%;

[0049] (2) Towards 8m 3 Add 6.0m 3 Pure water, 200L of 15% ammonia solution, and 15L of 25% liquid caustic soda are mixed to form a base solution with a pH of 12.0 and an ammonia concentration of 10g / L, and the temperature is raised to 40°C.

[0050] (3) The prepared nickel-cobalt-manganese ternary solution, liquid alkali and ammonia solution were pumped into the reactor at a flow rate of 350 L / h, 130 L / h and 50 L / h respectively through metering pumps. The initial stirring speed was 280 rpm and the temperature was 40 ° C. The particles nucleated and gradually grew. The stirring speed decreased by 50 rpm for every 18 hours of reaction time. At the same time, when the D50 was 7-9 μm, the reaction began to overflow. When it was 11 μm, the overflow was closed and the concentration was re-concentrated.

[0051] (4) When the particle D50 reaches 16.0 μm, stop feeding and discharge the material into the aging tank;

[0052] (5) The materials are washed, dehydrated, dried, calcined, mixed, screened, and electromagnetically ironed before being packaged into finished products.

[0053] Example 5

[0054] A method for preparing a high-sphericity ultra-high nickel ternary precursor comprises the following steps:

[0055] (1) preparing a ternary solution with a concentration of 110 g / L and a molar ratio of nickel, cobalt and manganese of 97:2:1, a 35% by mass caustic soda solution, and a 20% by mass ammonia solution;

[0056] (2) Towards 8m 3 Add 5.5.0m 3 Pure water, 360L of 20% ammonia solution, and 25L of 35% liquid caustic soda are mixed to form a base solution with a pH of 11.8 and an ammonia concentration of 9.5g / L, and the temperature is raised to 48°C.

[0057] (3) The prepared nickel-cobalt-manganese ternary solution, liquid alkali and ammonia solution were pumped into the reactor at the flow rates of 450 L / h, 200 / h and 70 L / h respectively through metering pumps. The initial stirring speed was 400 rpm and the temperature was 48 ° C. The particles nucleated and gradually grew. The stirring speed decreased by 35 rpm for every 10 hours of reaction time. At the same time, when the D50 was 4.5-8.5 μm, the reaction began to overflow. When it was 12 μm, the overflow was closed and the solution was re-thickened.

[0058] (4) When the particle D50 reaches 17.0 μm, stop feeding and discharge the material into the aging tank;

[0059] (5) The materials are washed, dehydrated, dried, calcined, mixed, screened, and electromagnetically ironed before being packaged into finished products.

[0060] The ternary precursor prepared by the present invention was observed by SEM, and the SEM image is as follows: Figure 2 As shown in the figure, it can be seen that the ternary precursor prepared by the method disclosed in the present invention has very good sphericity and uniform particles without the generation of fine powder and cracked balls.

[0061] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a high-sphericity ultra-high nickel ternary precursor, characterized in that: During the coprecipitation reaction, the stirring speed is regulated to decrease step by step with the increase of the coprecipitation reaction time. For every 10-20 hours increase in the reaction time, the stirring speed is controlled to decrease by 5-20%; when the D50 of the product particles reaches 7-9 μm, the reaction begins to overflow; when the D50 of the product particles reaches 11-13 μm, the overflow is closed and re-concentration is carried out; when the particle size of the product particles reaches 15-20 μm, the addition is stopped to obtain a product system, and the solid content of the obtained product system is controlled to be 200-400 g / L.

2. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 1, characterized in that: The following steps are involved: (1) Liquid preparation: prepare ternary solution, liquid alkali solution, ammonia solution and base solution; (2) Coprecipitation reaction: adding ternary solution, liquid alkali solution, and ammonia solution to the base liquid, and performing coprecipitation reaction while stirring to obtain the product system; (3) Post-processing: After post-processing the product system, a high-sphericity ultra-high nickel ternary precursor product is obtained.

3. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 2, characterized in that: The total concentration of nickel salt, cobalt salt and manganese salt in the ternary liquid is 80-120 g / L, and the molar ratio of nickel, cobalt and manganese elements is (90-98):(1-5):(1-5); the concentration of the liquid alkali solution is 25%-35% by mass; and the concentration of the ammonia aqueous solution is 15%-20% by mass.

4. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 2, characterized in that: The base liquid includes pure water in a volume ratio of (4-6): (0.2-0.4): (0.01-0.03), a liquid alkali solution with a mass fraction concentration of 25%-35%, and an ammonia solution with a mass fraction concentration of 15%-20%; the ammonia concentration in the base liquid is 8-10 g / L and the pH is 10.5-12.

5. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 2, characterized in that: The reaction temperature of the coprecipitation reaction is 40-60° C., and the stirring speed is 250-400 rpm.

6. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 2, characterized in that: In the step (2), the flow ratio of the nickel-cobalt-manganese ternary solution, the liquid alkali solution and the ammonia solution when added is (30-50):(10-20):(3-7).

7. The method for preparing a high-sphericity ultra-high nickel ternary precursor according to claim 2, characterized in that: The post-processing in step (3) includes aging, washing, dehydration, drying, calcination, batch mixing, screening, and iron removal.

8. A high-sphericity ultra-high nickel ternary precursor prepared by the method for preparing a high-sphericity ultra-high nickel ternary precursor according to any one of claims 1 to 7.

9. Use of the high-sphericity ultra-high nickel ternary precursor according to claim 8 in lithium-ion batteries.

Images