High-nickel ternary precursor, preparation method and application thereof

Abstract

This invention relates to the field of ternary precursor technology, and discloses a high-nickel ternary precursor, its preparation method, and its application. A two-stage continuous process is employed. First, a precursor nucleus is prepared using a high-rotation-rate, low-ammonia-concentration, and high-pH process. Then, a shell is prepared using a low-rotation-rate, suitable-ammonia-concentration, and suitable-pH process, achieving precursor crystal growth along the ternary precursor matrix. <101> Preferential crystal plane growth and an XRD peak intensity ratio I101 / I001 > 1.2. The prepared high-nickel ternary cathode material, under 3.0–4.3V conditions with a 1.0C / 1.0C charge-discharge regime, achieved an initial discharge of 206 mAh / g and an initial coulombic efficiency > 96.0%; under 3.0–4.3V conditions with a 0.1C / 0.1C charge-discharge regime, the initial discharge reached 230 mAh / g with an initial coulombic efficiency above 92.50%, and the 1C / 0.1C capacity retention rate ≥ 89.5%, demonstrating excellent electrical performance.

Description

Technical Field

[0001] This invention relates to the field of ternary precursor technology, and in particular to a high-nickel ternary precursor, its preparation method, and its application. Background Technology

[0002] With the rapid iteration of new energy vehicles, high-end consumer electronics, and large-scale energy storage, end consumers are increasingly focusing on a dual breakthrough in high energy density and excellent rate performance for lithium batteries. In the new energy vehicle scenario, users seek ultra-long driving range to alleviate range anxiety, while also expecting rapid recharging in a short time. High-end smartphones, drones, and other consumer electronics products need to accommodate higher capacity within a limited volume while meeting the demands of high-frequency, high-power use. Energy storage systems also require batteries to stably output power under high-rate charging and discharging conditions, adapting to the fluctuating power supply characteristics of renewable energy. However, traditional lithium battery cathode materials (especially high-nickel systems) often present performance contradictions—while high nickel content can increase energy density, it easily leads to decreased crystal structure stability and increased lithium-ion transport resistance, making it difficult to achieve both high rate performance and fully meet the stringent requirements of end applications.

[0003] Against this backdrop, overcoming the aforementioned performance bottlenecks through precise technical design has become a core direction for industry R&D. This involves optimizing crystal growth conditions to achieve the directional arrangement of advantageous crystal planes, allowing the precursor crystal to grow along... <101> Preferential growth of crystal faces shortens the lithium-ion transport path, providing a feasible path for developing lithium battery materials that combine high capacity and excellent rate performance. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a high-nickel ternary precursor, its preparation method, and its application. The precursor crystal follows a specific pattern. <101> Preferential crystal plane growth resulted in high-nickel ternary cathode materials that, under 3.0–4.3V conditions and with a 1.0C / 1.0C charge-discharge regime, achieved an initial discharge capacity of 206 mAh / g and an initial coulombic efficiency >96.0%. Under 3.0–4.3V conditions and with a 0.1C / 0.1C charge-discharge regime, the initial discharge capacity reached 230 mAh / g, with an initial coulombic efficiency above 92.50% and a 1C / 0.1C capacity retention ≥89.5%.

[0005] To achieve this technical objective, the present invention adopts the following solution:

[0006] In a first aspect, the present invention provides a method for preparing a high-nickel ternary precursor, comprising the following steps: S1. Prepare a mixed salt solution of nickel, cobalt, and manganese as the first solution; prepare a sodium hydroxide solution as the second solution; prepare an ammonia solution as the third solution. S2. Inject pure water into the crystal nucleation vessel and the finished product vessel respectively, add the second solution to adjust the pH value, add reducing substances, and introduce protective gas to replace the air. S3. The first solution, the second solution, and the third solution are introduced into the crystallization reactor to carry out the reaction. The flow rate of the first solution is controlled at 0~30L / h, the flow rate of the third solution is controlled at 0~15L / h, and the flow rate of the second solution is automatically adjusted to regulate the pH value. S4. The first solution, the second solution, and the third solution are introduced into the finished product reactor for reaction. The flow rate of the first solution is controlled at 0~30L / h, the flow rate of the third solution is controlled at 0~15L / h, and the flow rate of the second solution is automatically adjusted to adjust the pH value and keep it lower than the pH value of the crystal nucleation reactor, with the difference maintained between 0.5 and 1.0. During the reaction, a peristaltic pump is used to inject the crystal nuclei in the crystal nucleation reactor into the finished product reactor. S5. After the particle size in the finished product reactor reaches the standard value and stabilizes, the product is subjected to aging and draining liquid, alkaline washing, water washing, and drying to obtain a high-nickel ternary precursor. The molecular formula of the product is Ni. X Co Y Mn Z (OH)2.

[0007] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0008] The method for preparing high-nickel ternary precursors provided by this invention employs a two-stage continuous process. First, precursor nuclei are prepared using a high-rotation-rate, low-ammonia-concentration, and high-pH process. Then, a shell is prepared using a low-rotation-rate, suitable-ammonia-concentration, and suitable-pH process, thereby achieving precursor crystal growth along the crystalline path. <101> Crystal planes grow preferentially, and the XRD peak intensity ratio I101 / I001>1.2.

[0009] Furthermore, in step S1, the total concentration of the three metal ions in the first solution is 0.5~2.5 mol / L, specifically 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, and 2.5 mol / L; The molar ratio of nickel, cobalt, and manganese is X:Y:Z, where X+Y+Z=1, 0.8<X<1.0, 0<Y<0.2, and 0<Z<0.2; specifically, it can be 95:3:2, 90:7:3, 85:10:5, or 80:10:10. The concentration of sodium hydroxide solution is 1~12 mol / L, specifically 1 mol / L, 2 mol / L, 5 mol / L, 7 mol / L, 10 mol / L, 10.8 mol / L, and 12 mol / L. The concentration of ammonia solution is 2~13 mol / L, specifically 2 mol / L, 4 mol / L, 6 mol / L, 8.5 mol / L, 10 mol / L, and 13 mol / L.

[0010] Furthermore, in step S2, the level of pure water injected into the crystal nucleation vessel and the finished product vessel is 70-90% of the total volume of the reaction vessel, specifically 70%, 80%, or 90%, preferably 80%; Add a second solution to adjust the pH value to 10~12, specifically 10, 10.5, 11, 11.2, 11.4, 11.6, 11.8, or 12; The reducing agent includes at least one of hydrazine hydrate or ascorbic acid. Adding a reducing agent removes dissolved oxygen from the water, ensuring that it is not oxidized during the reaction. The amount of reducing agent added is 0.01%. Nitrogen is used as the protective gas. It is introduced into the reactor to replace the air and is continuously introduced during the reaction to prevent the metal ions from oxidizing.

[0011] Further, in step S3, the ammonia concentration in the crystal nucleation vessel is maintained at 0~5 g / L, specifically 0.5 g / L, 1.0 g / L, 1.5 g / L, 2.0 g / L, 2.5 g / L, 3.0 g / L, 4.0 g / L, or 5.0 g / L; The temperature is maintained between 45 and 80℃, specifically 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, and 80℃. The stirring speed is controlled at 100~500 r / min, specifically 100 r / min, 200 r / min, 300 r / min, 400 r / min, and 500 r / min, with 500 r / min being the preferred speed. The pH value is maintained between 10.0 and 12.0, specifically 10, 10.5, 11, 11.2, 11.4, 11.6, 11.8, and 12.

[0012] Furthermore, in step S4, the ammonia concentration in the finished product reactor is maintained at 0~5g / L, specifically 0.5g / L, 1.0g / L, 1.5g / L, 2.0g / L, 2.5g / L, 3.0g / L, 4.0g / L, or 5.0g / L; The temperature is maintained between 45 and 80℃, specifically 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, and 80℃. The stirring speed is controlled at 100~500 r / min and lower than the stirring speed of the crystal nucleation vessel. Specifically, it can be 100 r / min, 200 r / min, 300 r / min, 400 r / min, or 500 r / min, with 300 r / min being the preferred speed. The pH value should be maintained between 9.0 and 11.5, specifically 9, 9.5, 10, 10.5, 11, 11.2, 11.4, and 11.5.

[0013] Furthermore, in steps S3 and S4, a protective gas is continuously introduced during the reaction to prevent the metal ions from oxidizing.

[0014] Furthermore, in step S3, the crystal nucleus particle size D50 in the crystal nucleation vessel is 2~4μm; in step S4, the finished product particle size D50 in the finished product vessel is 8~15μm.

[0015] Secondly, the present invention provides a high-nickel ternary precursor prepared by the aforementioned preparation method.

[0016] Thirdly, the present invention provides a method for applying a high-nickel ternary precursor, wherein the aforementioned high-nickel ternary precursor is used to prepare ternary cathode materials.

[0017] Furthermore, a high-nickel ternary precursor was mixed with lithium hydroxide at a ratio of 1:1.05 and sintered at 500~1000℃, oxygen concentration of 80%~100%, and time of 2~15h to prepare a ternary cathode material.

[0018] Compared with existing technologies, the high-nickel ternary cathode material prepared by this invention achieves an initial discharge efficiency of 206 mAh / g and an initial coulombic efficiency of >96.0% under 3.0~4.3V conditions with a 1.0C / 1.0C charge-discharge regime; and an initial discharge efficiency of 230 mAh / g and an initial coulombic efficiency of over 92.50% under 3.0~4.3V conditions with a 0.1C / 0.1C charge-discharge regime, with a 1C / 0.1C capacity retention rate ≥89.5%, demonstrating excellent electrical performance. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a high-nickel ternary precursor synthesis apparatus in an embodiment of the present invention.

[0020] Figure 2 This is an electron microscope image of the high-nickel ternary precursor with excellent magnification prepared in Example 1 of the present invention.

[0021] Figure 3 This is an electron microscope image of the high-nickel ternary precursor with excellent magnification prepared in Example 2 of the present invention.

[0022] Figure 4 This is an electron microscope image of the high-nickel ternary precursor prepared in Comparative Example 1 of this invention.

[0023] Figure 5 This is an electron microscope image of the high-nickel ternary precursor prepared in Comparative Example 2 of this invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0025] The schematic diagram of the synthesis apparatus used in the embodiments and comparative examples of this invention is shown below. Figure 1 As shown, the reactor includes a nucleation vessel and a finished product vessel. Both the nucleation vessel and the finished product vessel are equipped with a stirring device and a pH meter. Flow meters A1, A3, and A5 are installed on the inlet pipe of the nucleation vessel, and flow meters A2, A4, and A6 are installed on the inlet pipe of the finished product vessel. A peristaltic pump is installed between the nucleation vessel and the finished product vessel. During the reaction, the nuclei in the nucleation vessel enter the finished product vessel through the peristaltic pump.

[0026] Example 1

[0027] Prepare a first solution in which the molar ratio of nickel sulfate, cobalt sulfate, and manganese sulfate is 95:3:2, and the total concentration of the first solution is 2.0 mol / L. Prepare a second solution of 10.8 mol / L sodium hydroxide and a third solution of 8.5 mol / L ammonia solution.

[0028] Pure water was injected into the two reactors to 80% of their total volume. A second solution and a reducing agent, hydrazine hydrate, were added to the two reactors to ensure that the pH values ​​inside the reactors were 11.80 and 11.60, respectively, and the ammonia concentration was 1.5 g / L. At the same time, nitrogen gas was introduced into the reactors to ensure that the atmosphere inside the reactors was under nitrogen protection.

[0029] Crystal nucleus preparation: The first, second, and third solutions were introduced into the crystal nucleus reactor at appropriate flow rates through inlet pipes A1, A3, and A5, respectively, for reaction. The flow rate of the first solution was controlled at 10.8 L / h, the flow rate of the third solution was controlled at 0.2 ± 0.1 L / h, the ammonia concentration was maintained at 1.5 g / L, the stirring speed was controlled at 500 r / min, the temperature was maintained at 75℃, and the pH value of the reactor was automatically controlled at 11.80 ± 0.4 using the second solution to maintain the crystal nucleus particle size D50 = 3.5 μm in the finished product reactor.

[0030] Product Preparation: The first, second, and third solutions are introduced into the product reactor at appropriate flow rates through inlet pipes A2, A4, and A6 for reaction. The flow rate of the first solution is controlled at 10.8 L / h, the flow rate of the third solution at 0.2 ± 0.1 L / h, the ammonia concentration is maintained at 1.5 g / L, the stirring speed is controlled at 300 r / min, and the temperature is maintained at 75℃. The pH value of the reactor is automatically controlled to 11.40 ± 0.6 using the second solution to maintain the particle size D50 of the product in the reactor at 10.0 μm. Then, the pH value of the product reactor is gradually reduced to ensure that the pH difference between the product reactor and the nucleation reactor is within 0.65. A peristaltic pump is used to inject crystal nuclei from the nucleation reactor into the product reactor to maintain the particle size D50 of the product reactor at 10.0 μm.

[0031] After the particle size in the finished product reactor reaches the standard value, the material is taken out and prepared into qualified high-nickel ternary precursors through a fixed aging and drying process.

[0032] Using the above process, the finished product data is as follows: The first batch of peaks had a D10 of 4.84 μm, a D50 of 10.12 μm, a D90 of 18.62 μm, and a D100 of 30.08 μm, with an XRD peak intensity ratio I101 / I001 > 1.27. The second batch: D10 is 4.95μm, D50 is 10.15μm, D90 is 18.67μm, D100 is 30.45μm, and the XRD peak intensity ratio I101 / I001>1.29; The third batch: D10 is 4.86 μm, D50 is 10.12 μm, D90 is 18.27 μm, D100 is 30.07 μm, and the XRD peak intensity ratio I101 / I001 > 1.28; the finished electron microscope results are as follows: Figure 2 As shown.

[0033] Cathode material preparation: The prepared high-nickel ternary precursor was mixed uniformly with lithium hydroxide at a ratio of 1:1.05, and sintered at 750℃, 90% oxygen concentration, and for 12 hours. The prepared high-nickel ternary cathode material, under 3.0~4.3V conditions and a 1.0C / 1.0C charge-discharge regime, showed an initial discharge of 206.50 mAh / g and an initial coulombic efficiency of 97.12%; under 3.0~4.3V conditions and a 0.1C / 0.1C charge-discharge regime, the initial discharge was 230.61 mAh / g and the initial coulombic efficiency was 92.60%, with a 1C / 0.1C capacity retention of ≥89.54%.

[0034] Example 2

[0035] Prepare a first solution in which the molar ratio of nickel sulfate, cobalt sulfate, and manganese sulfate is 95:3:2, and the total concentration of the first solution is 2.0 mol / L. Prepare a second solution of 10.8 mol / L sodium hydroxide and a third solution of 8.5 mol / L ammonia solution.

[0036] Pure water was injected into the two reactors to 80% of their total volume. A second solution and a reducing agent, hydrazine hydrate, were added to the two reactors to ensure that the pH values ​​inside the reactors were 11.80 and 11.60, respectively, and the ammonia concentration was 1.5 g / L. At the same time, nitrogen gas was introduced into the reactors to ensure that the atmosphere inside the reactors was under nitrogen protection.

[0037] Crystal nucleus preparation: The first, second, and third solutions were introduced into the crystal nucleus reactor at appropriate flow rates through inlet pipes A1, A3, and A5, respectively. The flow rate of the first solution was controlled at 10.8 L / h, the flow rate of the third solution at 0.2 ± 0.1 L / h, the ammonia concentration was maintained at 2.0 g / L, the stirring speed was controlled at 500 r / min, and the temperature was maintained at 75℃. The pH value of the reactor was automatically controlled to 11.80 ± 0.4 using the second solution to maintain the crystal nucleus particle size D50 = 3.5 μm.

[0038] Product Preparation: The first, second, and third solutions are introduced into the product reactor at appropriate flow rates through inlet pipes A2, A4, and A6 for reaction. The flow rate of the first solution is controlled at 10.8 L / h, the flow rate of the third solution at 0.2 ± 0.1 L / h, the ammonia concentration is maintained at 2.0 g / L, the stirring speed is controlled at 300 r / min, and the temperature is maintained at 75℃. The pH value of the reactor is automatically controlled to 11.40 ± 0.6 using the second solution to maintain the particle size D50 of the product in the reactor at 10.0 μm. Then, the pH value of the product reactor is gradually reduced to ensure that the pH difference between the product reactor and the nucleation reactor is 0.85. A peristaltic pump is used to inject crystal nuclei from the nucleation reactor into the product reactor to maintain the particle size D50 of the product reactor at 10.0 μm.

[0039] After the particle size in the finished product reactor reaches the standard value, the material is taken out and prepared into qualified high-nickel ternary precursors through a fixed aging and drying process.

[0040] Using the above process, the finished product data is as follows: The first batch of peaks had a D10 of 4.88 μm, a D50 of 10.17 μm, a D90 of 18.82 μm, and a D100 of 30.18 μm, with an XRD peak intensity ratio I101 / I001 > 1.28; The second batch: D10 is 4.91 μm, D50 is 10.25 μm, D90 is 18.77 μm, D100 is 30.35 μm, and the XRD peak intensity ratio I101 / I001>1.31; The third batch: D10 is 4.88 μm, D50 is 10.22 μm, D90 is 18.37 μm, D100 is 30.17 μm, and the XRD peak intensity ratio I101 / I001 > 1.25; the finished electron microscope results are as follows: Figure 3 As shown.

[0041] Cathode material preparation: The prepared high-nickel ternary precursor was mixed with lithium hydroxide at a ratio of 1:1.05 and sintered at 750℃, 90% oxygen concentration, and for 12 hours. The resulting high-nickel ternary cathode material, under 3.0~4.3V conditions and a 1.0C / 1.0C charge-discharge regime, showed an initial discharge of 206.10 mAh / g and an initial coulombic efficiency of 96.92%. Under 3.0~4.3V conditions and a 0.1C / 0.1C charge-discharge regime, the initial discharge was 229.51 mAh / g and the initial coulombic efficiency was 92.50%, with a 1C / 0.1C capacity retention rate ≥89.80%.

[0042] Comparative Example 1

[0043] Prepare a first solution in which the molar ratio of nickel sulfate, cobalt sulfate, and manganese sulfate is 95:3:2, and the total concentration of the first solution is 2.0 mol / L. Prepare a second solution of 10.8 mol / L sodium hydroxide and a third solution of 8.5 mol / L ammonia solution.

[0044] Pure water was injected into the two reactors to 80% of their total volume. A second solution and a reducing agent, hydrazine hydrate, were added to the two reactors to ensure that the pH values ​​inside the reactors were 11.80 and 11.60, respectively, and the ammonia concentration was 1.5 g / L. At the same time, nitrogen gas was introduced into the reactors to ensure that the atmosphere inside the reactors was under nitrogen protection.

[0045] Crystal nucleus preparation: The first, second, and third solutions were introduced into the crystal nucleus reactor at appropriate flow rates through inlet pipes A1, A3, and A5, respectively. The flow rate of the first solution was controlled at 10.8 L / h, the flow rate of the third solution at 0.2 ± 0.1 L / h, the ammonia concentration was maintained at 2.0 g / L, the stirring speed was controlled at 500 r / min, and the temperature was maintained at 75℃. The pH value of the reactor was automatically controlled to 11.80 ± 0.4 using the second solution to maintain the crystal nucleus particle size D50 = 3.5 μm.

[0046] Product Preparation: The first, second, and third solutions are introduced into the product reactor at appropriate flow rates through inlet pipes A2, A4, and A6 for reaction. The flow rate of the first solution is controlled at 10.8 L / h, and the flow rate of the third solution is controlled at 0.2 ± 0.1 L / h. The ammonia concentration is maintained at 2.0 g / L, the stirring speed is controlled at 300 r / min, and the temperature is maintained at 75℃. The pH value of the reactor is automatically controlled to 11.40 ± 0.6 using the second solution to maintain the particle size D50 of the product in the reactor at 10.0 μm. Then, the pH value of the product reactor is gradually reduced to ensure that the pH difference between the product reactor and the nucleation reactor is within 1.20. A peristaltic pump is used to inject crystal nuclei from the nucleation reactor into the product reactor to maintain the particle size D50 of the product reactor at 10.0 μm.

[0047] After the particle size in the finished product reactor reaches the standard value, the material is taken out and prepared into qualified high-nickel ternary precursors through a fixed aging and drying process.

[0048] Using the above process, the finished product data is as follows: The first batch of peaks had a D10 of 4.92 μm, a D50 of 10.27 μm, a D90 of 18.72 μm, and a D100 of 30.04 μm, with an XRD peak intensity ratio I101 / I001 > 1.10; The second batch: D10 is 4.85μm, D50 is 10.05μm, D90 is 18.70μm, D100 is 30.15μm, and the XRD peak intensity ratio I101 / I001>1.14; The third batch: D10 is 4.82 μm, D50 is 10.12 μm, D90 is 18.27 μm, D100 is 30.07 μm, and the XRD peak intensity ratio I101 / I001 > 1.05; the finished electron microscope results are as follows: Figure 4 As shown.

[0049] Cathode material preparation: The prepared high-nickel ternary precursor was mixed with lithium hydroxide at a ratio of 1:1.05 and sintered at 750℃, 90% oxygen concentration, and for 12 hours. The resulting high-nickel ternary cathode material, under 3.0~4.3V conditions and a 1.0C / 1.0C charge-discharge regime, showed an initial discharge capacity of 198.10 mAh / g and an initial coulombic efficiency of 94.52%. Under 3.0~4.3V conditions and a 0.1C / 0.1C charge-discharge regime, the initial discharge capacity was 228.51 mAh / g and the initial coulombic efficiency was 92.34%. The 1C / 0.1C capacity retention rate was ≥86.70%.

[0050] Comparative Example 2

[0051] Prepare a first solution in which the molar ratio of nickel sulfate, cobalt sulfate, and manganese sulfate is 95:3:2, and the total concentration of the first solution is 2.0 mol / L. Prepare a second solution of 10.8 mol / L sodium hydroxide and a third solution of 8.5 mol / L ammonia solution.

[0052] Fill the finished product reactor with pure water to 80% of its total volume. Add the second solution and the reducing agent hydrazine hydrate to the finished product reactor to ensure that the pH value inside the reactor is 11.80 and the ammonia concentration is 2.0 g / L. At the same time, purify the reactor with nitrogen to ensure that the atmosphere inside the reactor is under nitrogen protection.

[0053] Product preparation: The first, second, and third solutions are introduced into the product reactor at appropriate flow rates through inlet pipes A2, A4, and A6 for reaction. The flow rate of the first solution is controlled at 10.8 L / h, the flow rate of the third solution is controlled at 0.2 ± 0.1 L / h, the ammonia concentration is maintained at 2.0 g / L, the stirring speed is controlled at 300 r / min, the temperature is maintained at 75℃, and the pH value of the reactor is automatically controlled at 11.40 ± 0.6 using the second solution to maintain the particle size D50 of the product in the product reactor at 10.0 μm.

[0054] After the particle size in the finished product reactor reaches the standard value, the material is taken out and prepared into qualified high-nickel ternary precursors through a fixed aging and drying process.

[0055] Using the above process, the finished product data is as follows: The first batch of peaks had a D10 of 4.72 μm, a D50 of 10.17 μm, a D90 of 18.92 μm, and a D100 of 31.04 μm, with an XRD peak intensity ratio I101 / I001 > 1.02; The second batch: D10 is 4.65μm, D50 is 10.05μm, D90 is 19.27μm, D100 is 30.15μm, and the XRD peak intensity ratio I101 / I001>0.99; The third batch: D10 is 4.62 μm, D50 is 10.12 μm, D90 is 18.97 μm, D100 is 30.57 μm, and the XRD peak intensity ratio I101 / I001 > 1.05; the finished electron microscope results are as follows: Figure 5 As shown.

[0056] Cathode material preparation: The prepared high-nickel ternary precursor was mixed with lithium hydroxide at a ratio of 1:1.05 and sintered at 750℃, 90% oxygen concentration, and for 12 hours. The resulting high-nickel ternary cathode material exhibited an initial discharge of 196.22 mAh / g and an initial coulombic efficiency of 93.52% under 3.0~4.3V conditions and a 1.0C / 1.0C charge-discharge regime. Under 3.0~4.3V conditions and a 0.1C / 0.1C charge-discharge regime, the initial discharge was 226.61 mAh / g and the initial coulombic efficiency was 92.40%, with a 1C / 0.1C capacity retention rate ≥86.60%.

[0057] Table 1. Statistical Table of Electrical Properties of Cathode Materials under Charge-Discharge Regime

[0058]

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, they should all be considered to be within the protection scope of the present invention.

Claims

1. A method for preparing a high-nickel ternary precursor, characterized in that, Includes the following steps: S1. Prepare a mixed salt solution of nickel, cobalt, and manganese as the first solution; Prepare a sodium hydroxide solution as the second solution; Prepare an ammonia solution as the third solution; S2. Inject pure water into the crystal nucleation vessel and the finished product vessel respectively, add the second solution to adjust the pH value, add reducing substances, and introduce protective gas to replace the air. S3. The first solution, the second solution, and the third solution are introduced into the crystallization reactor to carry out the reaction. The flow rate of the first solution is controlled at 0~30L / h, the flow rate of the third solution is controlled at 0~15L / h, and the flow rate of the second solution is automatically adjusted to regulate the pH value. S4. The first solution, the second solution, and the third solution are introduced into the finished product reactor for reaction. The flow rate of the first solution is controlled at 0~30L / h, the flow rate of the third solution is controlled at 0~15L / h, and the flow rate of the second solution is automatically adjusted to adjust the pH value and keep it lower than the pH value of the crystal nucleation reactor, with the difference maintained between 0.5 and 1.

0. During the reaction, a peristaltic pump is used to inject the crystal nuclei in the crystal nucleation reactor into the finished product reactor. S5. After the particle size in the finished product reactor reaches the standard value and stabilizes, the product is subjected to aging and draining of the liquid, alkaline washing, water washing, and drying to obtain a high-nickel ternary precursor. The molecular formula of the product is Ni. X Co Y Mn Z (OH)2.

2. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In step S1, the total concentration of the three metal ions in the first solution is 0.5~2.5 mol / L, and the molar ratio of nickel, cobalt and manganese is X:Y:Z, where X+Y+Z=1, 0.8<X<1.0, 0<Y<0.2, and 0<Z<0.

2. And / or, the concentration of the sodium hydroxide solution is 1~12 mol / L; And / or, the concentration of the ammonia solution is 2~13 mol / L.

3. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In step S2, the level of pure water injected into the nucleation vessel and the finished product vessel is 70-90% of the total volume of the reaction vessel; And / or, adjust the pH value to 10~12; And / or, the reducing agent includes at least one of hydrazine hydrate or ascorbic acid, added in an amount of 0.01%; And / or, the protective gas is nitrogen.

4. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In step S3, the ammonia concentration in the crystallization vessel is maintained at 0~5g / L, the temperature is maintained at 45~80℃, the stirring speed is controlled at 100~500r / min, and the pH value is maintained at 10.0~12.

0.

5. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In step S4, the ammonia concentration in the finished product reactor is maintained at 0~5g / L, the temperature is maintained at 45~80℃, the stirring speed is controlled at 100~500r / min and lower than the stirring speed of the crystal nucleation reactor, and the pH value is maintained at 9.0~11.

5.

6. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In steps S3 and S4, a protective gas is continuously introduced during the reaction to prevent the metal ions from oxidizing.

7. The method for preparing the high-nickel ternary precursor according to claim 1, characterized in that, In step S3, the crystal nucleus particle size D50 in the crystal nucleation vessel is 2~4μm; in step S4, the finished product particle size D50 in the finished product vessel is 8~15μm.

8. A high-nickel ternary precursor, characterized in that, It is prepared by the preparation method according to any one of claims 1-7.

9. A method for applying a high-nickel ternary precursor, characterized in that, The high-nickel ternary precursor described in claim 8 is used to prepare ternary cathode materials.

10. The method of applying the high-nickel ternary precursor according to claim 9, characterized in that, A high-nickel ternary precursor was mixed with lithium hydroxide at a ratio of 1:1.05 and sintered at 500-1000℃, oxygen concentration of 80%-100%, and time of 2-15h to prepare a ternary cathode material.

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