Nickel-cobalt-manganese ternary precursor and preparation method thereof, positive electrode material, and battery

Abstract

The present application relates to the field of battery technology, and provides a nickel-cobalt-manganese ternary precursor and a preparation method thereof, a positive electrode material, and a battery. The preparation method comprises: subjecting a mixed metal salt solution to a first coprecipitation reaction to prepare a nickel-cobalt-manganese ternary precursor seed; the first coprecipitation reaction comprises a first stage reaction and a second stage reaction in sequence; subjecting a mixed metal salt solution and a nickel-cobalt-manganese ternary precursor seed to a second coprecipitation reaction to prepare a nickel-cobalt-manganese ternary precursor; the second coprecipitation reaction comprises a third stage reaction and a fourth stage reaction in sequence; the fourth stage reaction is relative to the third stage reaction: the pH increases, and the flow rate of the mixed metal salt solution increases. The nickel-cobalt-manganese ternary precursor provided in the present application has good whisker consistency, secondary particle consistency, and a high internal porosity, so that the subsequently prepared positive electrode material has higher safety performance, cycle performance, and higher specific capacity.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a nickel-cobalt-manganese ternary precursor and a preparation method and application thereof, as well as a positive electrode material and a battery. Background Art

[0002] As the new energy vehicle industry continues to flourish, the performance indicators and cost requirements for lithium-ion batteries, the core components of new energy vehicles, are also rising rapidly. Against this background, positive electrode materials composed of nickel-cobalt-manganese layered oxides are gradually moving towards high nickel. Although high-nickel positive electrode materials effectively improve the energy density of batteries, the poor cycle performance of high-nickel positive electrodes and the serious performance degradation during the cycle restrict their development and application.

[0003] A positive electrode precursor refers to a compound or mixture used to prepare positive electrode materials for lithium-ion batteries, while a ternary precursor specifically refers to a precursor compound composed of nickel, cobalt, and manganese. At present, the most commonly used method for synthesizing high-nickel ternary precursors is coprecipitation, which produces a synergistic effect between nickel, cobalt, and manganese through coprecipitation, giving full play to the advantages of the three elements. Studies have shown that the structure of the high-nickel ternary precursor changes little after lithium mixing and high-temperature sintering, indicating that the structure of the high-nickel positive electrode material largely inherits the structure of the precursor, which is reflected in the performance. Therefore, how to design and optimize the structure of the high-nickel precursor (hereinafter referred to as the precursor) to improve the stability of lithium-ion batteries is of great significance to battery development. Summary of the invention

[0004] The purpose of this application is to provide a nickel-cobalt-manganese ternary precursor and its preparation method, positive electrode material, and battery, aiming to solve the problem of how to design and optimize the structure of a high-nickel precursor (hereinafter referred to as the precursor) when preparing the ternary precursor by a co-precipitation method to improve the stability of lithium-ion batteries.

[0005] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0006] In a first aspect, the present application provides a method for preparing a nickel-cobalt-manganese ternary precursor, comprising: preparing a mixed metal salt solution containing nickel, cobalt and manganese; subjecting the mixed metal salt solution to a first coprecipitation reaction to prepare nickel-cobalt-manganese ternary precursor seed crystals; the first coprecipitation reaction sequentially comprises a first-stage reaction and a second-stage reaction, and the pH and the flow rate of the mixed metal salt solution in the second-stage reaction are the same or different relative to the first-stage reaction; subjecting the mixed metal salt solution to a second coprecipitation reaction with the nickel-cobalt-manganese ternary precursor seed crystals to prepare the nickel-cobalt-manganese ternary precursor; the second coprecipitation reaction sequentially comprises a third-stage reaction and a fourth-stage reaction; the fourth-stage reaction is relative to the third-stage reaction: the pH is increased, and the flow rate of the mixed metal salt solution is increased.

[0007] In order to improve the strength of primary particles, the consistency of secondary particles, and improve the porosity, the present application optimizes the synthesis method and adopts a method of simultaneously increasing the flow rate and pH of a mixed metal salt solution. By increasing the pH, the supersaturation of the reaction system is increased and the growth rate of secondary particles is slowed, thereby alleviating the problem of primary particle refinement caused by increasing the flow rate of the mixed metal solution, allowing them to grow fully, thereby improving the consistency of the primary particles, improving their strength, reducing the generation of small secondary particles, further improving the consistency of the secondary particles, and improving the porosity, thereby preparing a particle structure that is loose inside and highly dense outside.

[0008] In the second aspect, the present application provides a nickel-cobalt-manganese ternary precursor, including a crystal core and a seed layer, a transition layer and a stabilization layer that sequentially cover the crystal core; the porosity of the crystal core is 5.0% to 20.0%, the porosity of the seed layer is 1.0% to 6.0%, the porosity of the transition layer is 3.0% to 8.0%, the porosity of the stabilization layer is 2.0% to 5.0%, and the total porosity of the nickel-cobalt-manganese ternary precursor is 3.0% to 6.0%; the volume distribution diameter K of the nickel-cobalt-manganese ternary precursor particles is 90 ≦0.50; In Avizo characterization, 50% of the lengths of the primary particles of the nickel-cobalt-manganese ternary precursor are 400 nm~500 nm, and 50% of the widths are 100 nm~180 nm.

[0009] The nickel-cobalt-manganese ternary precursor provided by the present application has a porosity gradient distribution from the inside to the outside, which first decreases, then increases, and then decreases, which is conducive to full contact between the positive electrode material and the electrolyte, improves the conductivity of the positive electrode material, the lithium ion deintercalation rate, and enhances the capacity of the positive electrode material. It can also improve particle strength and stress release, improve positive electrode cycle performance, and reduce impedance.

[0010] The nickel-cobalt-manganese ternary precursor provided in the present application has good whisker consistency, secondary particle consistency and high internal porosity, so that the subsequently prepared positive electrode material has higher safety performance, cycle performance and higher specific capacity.

[0011] In a third aspect, the present application provides a positive electrode material, the preparation raw materials of which include the nickel-cobalt-manganese ternary precursor obtained by the above preparation method, or the above nickel-cobalt-manganese ternary precursor.

[0012] The positive electrode material prepared using the nickel-cobalt-manganese ternary precursor of the present application has higher safety performance, cycle performance and higher specific capacity.

[0013] In a fourth aspect, the present application provides a battery comprising the above-mentioned positive electrode material.

[0014] The battery may be a lithium battery, which includes at least one of a lithium ion battery, a solid-state lithium battery and a lithium polymer battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a 200-fold SEM image of the nickel-cobalt-manganese ternary precursor provided in Example 1 of the present application;

[0017] Figure 2 This is a SEM image of primary particles of the nickel-cobalt-manganese ternary precursor provided in Example 1 of the present application;

[0018] Figure 3 is a cross-sectional view of the nickel-cobalt-manganese ternary precursor provided in Example 1 of the present application;

[0019] Figure 4 1 is a SEM image of the nickel-cobalt-manganese ternary precursor provided in Example 2 of the present application; wherein, Figure (a) represents a 200-fold SEM image, Figure (b) represents a primary particle SEM image, and Figure (c) represents a cross-sectional view;

[0020] Figure 5 3 is a SEM image of the nickel-cobalt-manganese ternary precursor provided in Example 3 of the present application; wherein, Figure (a) represents a 200-fold SEM image, Figure (b) represents a primary particle SEM image, and Figure (c) represents a cross-sectional view;

[0021] Figure 6 It is a SEM image of the nickel-cobalt-manganese ternary precursor provided in Comparative Example 1; wherein, Figure (a) represents a 200-fold SEM image, Figure (b) represents a primary particle SEM image, and Figure (c) represents a cross-sectional view;

[0022] Figure 7 It is a SEM image of the nickel-cobalt-manganese ternary precursor provided in Comparative Example 2; wherein, Figure (a) represents a 200-fold SEM image, Figure (b) represents a primary particle SEM image, and Figure (c) represents a cross-sectional view;

[0023] Figure 8 It is the SEM image of the nickel-cobalt-manganese ternary precursor of comparative example 3; wherein, Figure (a) represents a 200-fold SEM image, Figure (b) represents a primary particle SEM image, and Figure (c) represents a cross-sectional view. DETAILED DESCRIPTION

[0024] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0025] In this application, the term "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects are in an "or" relationship.

[0026] In this application, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0027] It should be understood that in the various embodiments of the present application, the size of the serial numbers of the above-mentioned processes does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0028] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0029] The weight of the relevant components mentioned in the embodiment description of the present application can not only refer to the specific content of each component, but also indicate the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the embodiment description of the present application, it is within the scope disclosed in the embodiment description of the present application. Specifically, the mass described in the embodiment description of the present application can be a mass unit known in the chemical industry such as µg, mg, g, kg, etc.

[0030] The first aspect of an embodiment of the present application provides a method for preparing a nickel-cobalt-manganese ternary precursor, comprising: preparing a mixed metal salt solution containing nickel, cobalt and manganese; subjecting the mixed metal salt solution to a first coprecipitation reaction to prepare nickel-cobalt-manganese ternary precursor seed crystals; the first coprecipitation reaction sequentially comprises a first-stage reaction and a second-stage reaction, and the second-stage reaction has the same or different pH and mixed metal salt solution flow rate relative to the first-stage reaction; subjecting the mixed metal salt solution to a second coprecipitation reaction with the nickel-cobalt-manganese ternary precursor seed crystals to prepare the nickel-cobalt-manganese ternary precursor; the second coprecipitation reaction sequentially comprises a third-stage reaction and a fourth-stage reaction; and the fourth-stage reaction is relative to the third-stage reaction in that: the pH is increased and the mixed metal salt solution flow rate is increased.

[0031] The embodiment of the present application provides a method for improving the consistency of primary particles and secondary particles and uniformly increasing the porosity, thereby realizing the coordinated regulation of the precursor crystal structure, morphology, and particle distribution. The primary whiskers of the nickel-cobalt-manganese ternary precursor particles prepared by the method have high consistency, high internal porosity and external density, ensuring stress release, and improving particle strength. The consistency of the secondary particles is improved, so that the subsequently prepared battery has higher cycle performance and lower DCR (direct current internal resistance) growth rate, which improves the stability of the lithium-ion battery.

[0032] At present, under the common synthesis method in the industry, as the secondary particles grow, the primary particles on the surface of the sphere will gradually become thinner and messy due to the influence of the fluid, resulting in a gradual increase in the porosity; at the same time, in order to increase production capacity, the flow rate of the mixed metal solution will be increased, which will aggravate the refinement of the primary particles and excessive porosity, resulting in the primary particles of the positive electrode being thin and short after sintering, with a large specific surface area and low particle strength. At the same time, the thin primary particles have low strength during the synthesis process, and fall off after being impacted by force to become crystal nuclei, and then grow again to form small secondary particles, and the consistency of the secondary particles is reduced. Therefore, the primary particle consistency, internal porosity, and secondary particle consistency of the precursor have complex and interrelated effects on the performance of the positive electrode material. When designing and preparing ternary precursor materials, how to balance these factors and improve the primary particle consistency, secondary particle consistency, and porosity at the same time to achieve the obtained precursor material for packaging The obtained battery has higher stability is of great significance to battery development.

[0033] In order to improve the strength of primary particles, the consistency of secondary particles, and improve the porosity, the present application optimizes the synthesis method and adopts a method of simultaneously increasing the flow rate and pH of a mixed metal salt solution. By increasing the pH, the supersaturation of the reaction system is increased and the growth rate of secondary particles is slowed, thereby alleviating the problem of primary particle refinement caused by increasing the flow rate of the mixed metal solution, allowing them to grow fully, thereby improving the consistency of the primary particles, improving their strength, reducing the generation of small secondary particles, further improving the consistency of the secondary particles, and improving the porosity, thereby preparing a particle structure that is loose inside and highly dense outside.

[0034] In the embodiment of the present application, the pH and the flow rate of the mixed metal salt solution in the second stage reaction are the same or different from those in the first stage reaction. For example, the pH in the second stage reaction can be reduced or kept unchanged relative to the first stage reaction; the flow rate of the mixed metal salt solution in the second stage reaction can be increased or kept unchanged relative to the first stage reaction.

[0035] Further, in the third stage reaction, when the particle size D3 in the reaction system is monitored to be 9.0 μm~20.0 μm, the nickel-cobalt-manganese ternary precursor is obtained; further, D3 is 11.0 μm~15.0 μm. D3 represents the volume distribution average particle size D of the precursor particles. v50 , is the sum of all layer diameters or thicknesses.

[0036] In some embodiments, the fourth stage reaction is relative to the third stage reaction: the pH is increased by 0.5-1.2, and the flow rate of the mixed metal salt solution is increased by 2-5 times.

[0037] On the one hand, if the pH is too low or the flow rate of the mixed metal salt solution is too high, the particle growth will be accelerated, the primary particle thickness will be too low, the particle strength will be reduced, and there will be a risk of particle breakage during the production process, which is not conducive to the stability of the positive electrode charge and discharge process. On the other hand, if the pH is too high or the flow rate of the mixed metal salt solution is too low, the primary particle thickness will be too thick, which is not conducive to the diffusion of lithium salts during sintering and the electrolyte infiltration during the positive electrode charge and discharge process, affecting the capacity and cycle performance. At the same time, it will cause the growth time to become longer, which is not conducive to the industrial application of products and technologies.

[0038] The fourth stage reaction is relative to the third stage reaction: pH increases by 0.5 to 1.2. For example, pH increases by 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, etc.

[0039] The fourth stage reaction is relative to the third stage reaction: the flow rate of the mixed metal salt solution increases by 2 to 5 times. For example, the flow rate of the mixed metal salt solution increases by 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, etc.

[0040] In some embodiments, the pH in the third stage reaction is 9.8~12.0, and the pH in the fourth stage reaction is 10.1~12.3; and / or, the flow rate of the mixed metal salt solution in the third stage reaction is 12 L / h~18 L / h, and the flow rate of the mixed metal salt solution in the fourth stage reaction is 43 L / h~53 L / h.

[0041] The pH in the third stage reaction is 9.8 to 12.0, for example, pH 9.8, 10.0, 10.2, 10.4, 10.6, 10.8, 11.0, 11.2, 11.4, 11.6, 11.8, 12.0, etc.

[0042] The pH in the fourth stage reaction is 10.1-12.3, for example, pH 10.1, 10.3, 10.5, 10.7, 10.7, 10.9, 11.1, 11.3, 11.5, 11.7, 11.9, 12.0, etc.

[0043] The flow rate of the mixed metal salt solution in the third stage reaction is 12 L / h to 18 L / h, for example, the flow rate of the mixed metal salt solution is 12 L / h, 13 L / h, 14 L / h, 15 L / h, 16 L / h, 17 L / h, 18 L / h, etc.

[0044] The flow rate of the mixed metal salt solution in the fourth stage reaction is 43 L / h to 53 L / h, for example, the flow rate of the mixed metal salt solution is 43 L / h, 44 L / h, 45 L / h, 46 L / h, 47 L / h, 48 L / h, 49 L / h, 50 L / h, 51 L / h, 52 L / h, 53 L / h, etc.

[0045] Furthermore, in the third stage reaction, the pH is 10.0-11.0.

[0046] Furthermore, in the third stage reaction, the flow rate of the mixed metal salt solution is 15 L / h.

[0047] Furthermore, in the fourth stage reaction, the pH is 10.4-11.3.

[0048] Furthermore, in the fourth stage reaction, the flow rate of the mixed metal salt solution is 48 L / h.

[0049] In some embodiments, during the fourth stage reaction, the stirring speed at the end of the reaction is lower than the stirring speed at the initial stage of the reaction.

[0050] In the fourth stage reaction, the present application controls the stirring speed to reduce, which is beneficial to improving the consistency of the secondary particles and avoiding the particles from sticking and breaking, which affects the positive electrode performance. The reduction method can adopt a continuous reduction method.

[0051] Further, in the fourth stage reaction, the initial stirring speed is 300 rpm~520 rpm, for example, 300 rpm, 320 rpm, 340 rpm, 360 rpm, 380 rpm, 400 rpm, 420 rpm, 440 rpm, 460 rpm, 480 rpm, 500 rpm, 520 rpm, etc.; further, the initial stirring speed is 380 rpm~500 rpm.

[0052] Further, in the fourth stage reaction, the stirring speed is finally reduced to 100 rpm~240 rpm, for example, 100 rpm, 120 rpm, 140 rpm, 160 rpm, 180 rpm, 200 rpm, 220 rpm, 240 rpm; further, the stirring speed is finally reduced to 120 rpm~200 rpm.

[0053] During the fourth stage reaction, the stirring speed at the end of the reaction is lower than that at the initial stage of the reaction, for example: the stirring speed at the initial stage of the reaction is 430 rpm, and the stirring speed at the end of the reaction is 172 rpm; the stirring speed at the initial stage of the reaction is 300 rpm, and the stirring speed at the end of the reaction is 150 rpm; the stirring speed at the initial stage of the reaction is 520 rpm, and the stirring speed at the end of the reaction is 260 rpm.

[0054] Furthermore, in the first stage reaction and / or the second stage reaction and / or the third stage reaction, the stirring speed is 300 rpm to 520 rpm; furthermore, the stirring speed is 380 rpm to 500 rpm.

[0055] In some embodiments, nickel-cobalt-manganese ternary precursor seed crystals are prepared, and the second stage reaction is relative to the first stage reaction: pH is lowered, and the flow rate of the mixed metal salt solution is increased.

[0056] Different from the high pH in the first stage reaction, the lower pH in the second stage reaction will make the particles tend to precipitate and grow, and the system will no longer generate crystal nuclei, which is conducive to improving the crystallinity of the seed crystals and improving the strength of the particles. At the same time, increasing the flow rate of the mixed metal salt solution is conducive to controlling the internal porosity and keeping it within a reasonable range, which is also conducive to increasing production capacity and industrial application.

[0057] Furthermore, in the second stage reaction, the pH is reduced by 0.6-1.0 relative to the first stage reaction, and the flow rate of the mixed metal salt solution is increased by 2-5 times. For example, the pH is reduced by 0.6, 0.7, 0.8, 0.9, 1.0; for example, the flow rate of the mixed metal salt solution is increased by 1 time, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, 5 times, etc.

[0058] Furthermore, in the first stage reaction, the pH value is 11.5-12.0; further, 11.8-12.0.

[0059] Furthermore, in the first stage reaction, the flow rate of the mixed metal salt solution is 7 L / h-11 L / h.

[0060] Furthermore, in the second stage reaction, the pH value is 10.5-11.4; further, 10.8-11.3.

[0061] Furthermore, in the second stage reaction, the flow rate of the mixed metal salt solution is 25 L / h-35 L / h.

[0062] Further, after the first stage reaction is carried out for 45 min to 75 min, the particle size D1 in the reaction system is monitored and the second stage reaction is entered. After the first stage reaction is carried out for 45 min to 75 min, the particle size D1 in the reaction system will reach the expected range.

[0063] Further, D1 is a seed diameter, and D1 is 1.0 μm to 1.5 μm, for example, D1 is 1.0 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, or 1.5 μm.

[0064] Furthermore, after the first stage reaction was carried out for 60 min, the particle size D1 in the reaction system was monitored and the second stage reaction was entered.

[0065] Furthermore, in the second stage reaction, the particle size D2 in the reaction system is monitored.

[0066] Further, when D2 is 2 μm to 5 μm, the seed is used for the third stage reaction; for example, D2 is 2.0 μm, 2.5 μm, 3.0 μm, 3.5 μm, 4.0 μm, 4.5 μm, 5.0 μm. Further, D2 is 3.5 μm to 4.5 μm. D2 represents the volume distribution average particle size D of the seed. v50 , which is the sum of the diameters of the nucleus layer and the seed layer.

[0067] In some embodiments, in the first stage reaction and / or the second stage reaction, the reaction temperature is 50°C to 75°C; further 55°C to 65°C.

[0068] In some embodiments, in the third stage reaction and / or the fourth stage reaction, the reaction temperature is 50°C to 75°C; further 60°C to 75°C.

[0069] In some embodiments, in the first stage reaction, and / or the second stage reaction, and / or the third stage reaction, and / or the fourth stage reaction, the mixed metal salt solution is an aqueous solution of a ternary mixed metal salt of nickel, cobalt and manganese.

[0070] Furthermore, the mixed metal salt solution includes at least one of sulfate, nitrate, chloride and acetate.

[0071] Furthermore, the concentration of the mixed metal salt solution is 115 g / L~140 g / L; furthermore, 120 g / L~135 g / L.

[0072] In some embodiments, in the first stage reaction, and / or the second stage reaction, and / or the third stage reaction, and / or the fourth stage reaction, the precipitant used in the co-precipitation reaction includes at least one of sodium hydroxide solution, sodium carbonate solution, sodium bicarbonate solution, ammonium carbonate solution and ammonium bicarbonate solution.

[0073] Furthermore, the mass concentration of the precipitant is 15% to 40%; furthermore, 20% to 35%.

[0074] In some embodiments, in the first stage reaction, and / or the second stage reaction, and / or the third stage reaction, and / or the fourth stage reaction, the complexing agent used in the coprecipitation reaction includes ammonia water.

[0075] Furthermore, the mass concentration of the complexing agent is 5% to 15%; furthermore, 6% to 11%.

[0076] In some embodiments, gas is introduced into the first stage reaction, and / or the second stage reaction, and / or the third stage reaction, and / or the fourth stage reaction; the gas is one or a mixture of nitrogen, helium and air.

[0077] In some embodiments, in the first stage reaction and / or the second stage reaction, the ammonia value is 1.0 g / L to 6.0 g / L; further, 2.5 g / L to 4.5 g / L.

[0078] In some embodiments, in the third stage reaction and / or the fourth stage reaction, the ammonia value is 2 g / L to 6 g / L; further, 2 g / L to 5 g / L.

[0079] In some embodiments, the coprecipitation reaction provided in the present application mainly includes two reaction processes (a first reaction process and a second reaction process). The first reaction process is mainly used to prepare nickel-cobalt-manganese ternary precursor seeds, and the second reaction process mainly uses the nickel-cobalt-manganese ternary precursor seeds prepared in the first reaction process to continue the reaction to prepare the nickel-cobalt-manganese ternary precursor. The first reaction process includes a first-stage reaction and a second-stage reaction, and the second reaction process includes a third-stage reaction and a fourth-stage reaction. In the first reaction process, the pH is adjusted to gradually decrease and the flow rate of the mixed metal salt solution is increased; in the second reaction process, the pH is adjusted to gradually increase and the flow rate of the mixed metal salt solution is increased, so as to achieve the preparation of a precursor material with high primary particle consistency, internal porosity gradient distribution, and high secondary particle consistency.

[0080] Furthermore, the coprecipitation reaction includes the steps of: preparing a base liquid, and then adding a metal salt solution, a precipitant and a complexing agent into the base liquid to carry out a coprecipitation reaction.

[0081] Furthermore, the first reaction process, i.e., preparing the nickel-cobalt-manganese ternary precursor seed crystal, comprises the following steps:

[0082] Preparation of base liquid: Under a certain atmosphere, water is used as the base liquid, and a precipitant and a complexing agent are added to the base liquid to make it the base liquid of the first reaction process.

[0083] Entering the first stage reaction: adding the mixed metal salt solution, precipitant and complexing agent into the base solution, maintaining the flow rate and pH value of the mixed metal salt solution unchanged.

[0084] Enter the second stage reaction: lower the pH, increase the flow rate of the mixed metal salt solution, and finally prepare the nickel-cobalt-manganese ternary precursor seed crystal.

[0085] Furthermore, the second reaction process, i.e., preparing the nickel-cobalt-manganese ternary precursor, comprises the following steps:

[0086] Preparation of base liquid: Under a certain atmosphere, water is used as the base liquid, the seed crystals obtained in the first reaction process are added, and the pH is adjusted to obtain the base liquid for the second reaction process.

[0087] Entering the third stage reaction: the mixed metal salt solution, precipitant, and complexing agent base solution are added, the pH value is maintained constant, and the flow rate of the mixed metal salt solution is maintained constant.

[0088] Entering the fourth stage reaction: increasing the pH, increasing the flow rate of the mixed metal salt solution, and finally synthesizing the nickel-cobalt-manganese ternary precursor.

[0089] In summary, the primary whiskers of the precursor particles prepared by the method of the present application have high consistency, high internal porosity, and improved consistency of the secondary particles, so that the subsequently prepared positive electrode material has higher safety performance, cycle performance and higher specific capacity.

[0090] A second aspect of an embodiment of the present application provides a nickel-cobalt-manganese ternary precursor, comprising a crystal core and a seed layer, a transition layer and a stabilization layer sequentially covering the crystal core; the porosity of the crystal core is 5.0% to 20.0%, the porosity of the seed layer is 1.0% to 6.0%, the porosity of the transition layer is 3.0% to 8.0%, the porosity of the stabilization layer is 2.0% to 5.0%, and the total porosity of the nickel-cobalt-manganese ternary precursor is 3.0% to 6.0%; the volume distribution diameter K of the nickel-cobalt-manganese ternary precursor particles is 90 ≦0.50; In Avizo characterization, 50% of the lengths of the primary particles of the nickel-cobalt-manganese ternary precursor are 400 nm~500 nm, and 50% of the widths are 100nm~180 nm.

[0091] The primary particle consistency, internal porosity, and secondary particle consistency of the nickel-cobalt-manganese ternary precursor have complex and interrelated effects on the performance of the positive electrode material. When designing and preparing nickel-cobalt-manganese ternary precursor materials, it is necessary to balance these factors and optimize them according to specific application requirements to achieve higher performance high-nickel positive electrode battery materials. The nickel-cobalt-manganese ternary precursor provided in this application has a gradient porosity distribution, a high porosity, and a high consistency between primary and secondary particles, thereby improving the electrochemical performance of the positive electrode material.

[0092] If the internal porosity of the nickel-cobalt-manganese ternary precursor is too low, it will not only affect the diffusion of lithium ions during the sintering process of the positive electrode material, but also reduce and shorten the active sites and ion diffusion channels, which is not conducive to the transmission and storage of ions in the electrolyte. It is also easy to cause the stress to be unable to be released when the volume of the positive electrode material changes during charging and discharging, affecting the capacity and power density of the battery.

[0093] The nickel-cobalt-manganese ternary precursor provided in the embodiment of the present application has a porosity gradient distribution from the inside to the outside, which first decreases, then increases, and then decreases, which is conducive to full contact between the positive electrode material and the electrolyte, improves the conductivity of the positive electrode material, the lithium ion deintercalation rate, and enhances the capacity of the positive electrode material. It can also improve particle strength and stress release, improve positive electrode cycle performance, and reduce impedance.

[0094] The nickel-cobalt-manganese ternary precursor provided in the embodiment of the present application has a loose internal structure and a dense external structure, and the particles are not easy to crack and the particle strength is enhanced, which is beneficial to improving the cycle performance and charge and discharge efficiency, and improving the battery performance. On the one hand, the internal loose structure of the nickel-cobalt-manganese ternary precursor particles can effectively release the stress caused by the change in particle volume during sintering to the positive electrode material and the positive electrode charge and discharge process, achieve the integrity of the particle structure, reduce the cracks and breakage of the particles from the inside to the outside, and improve the material cycle performance; the loose structure is conducive to the infiltration of the electrolyte, increase the lithium ion transmission rate, and improve the material cycle performance. On the other hand, the high density of the outside of the nickel-cobalt-manganese ternary precursor material particles can be effectively inherited to the ternary positive electrode material through the sintering process, so that the positive electrode material can use the dense structure to enhance the structural stability during the cycle process, effectively inhibit gas production, and thus improve the material cycle performance.

[0095] Furthermore, the porosity of the crystal core is 8% to 16%; and / or the porosity of the seed layer is 2.5% to 4.5%; and / or the porosity of the transition layer is 4.0% to 7.0% and / or the porosity of the stabilization layer is 3.0% to 4.5%.

[0096] Furthermore, the porosity of the crystal core is 8% to 16%, the porosity of the seed layer is 2.5% to 4.5%, the porosity of the transition layer is 4.0% to 7.0%, and the porosity of the stabilization layer is 3.0% to 4.5%.

[0097] Furthermore, the total porosity is 3.5%~5.0%.

[0098] If the secondary particles of the nickel-cobalt-manganese ternary precursor have poor consistency and wide diameter distance, the precursor and the positive electrode material will have poor sphericity and low consistency, affecting the sintering behavior, thereby affecting the mechanical stability and cycle life of the electrode material. The method for preparing the nickel-cobalt-manganese ternary precursor provided in this application can effectively control and improve the consistency of the secondary particles, thereby reducing K90, and has a narrow particle size distribution. When used in batteries, the secondary particles are more concentrated, which is beneficial to the sintering consistency of the positive electrode material, reducing the overburning and cracking problems of small particles, and improving the cycle stability. It can also improve the uniformity of operations such as doping and coating after the second sintering, and improve the mechanical stability and cycle stability of the material.

[0099] Furthermore, the volume distribution diameter K of the particles of the nickel-cobalt-manganese ternary precursor is 90 =(Dv 90 -Dv 10 ) / D v50 ≦0.50; further, in each SEM at 200 times, the number of particles <5μm accounts for ≤1%. Further, the volume distribution diameter distance K90 of the nickel-cobalt-manganese ternary precursor is ≤0.30; further, in each SEM at 200 times, the number of particles <5μm accounts for ≤0.5%.

[0100] If the primary particles of the nickel-cobalt-manganese ternary drive body are poorly consistent, the crystal interface contact area is small and the ion conductivity is poor after sintering into the positive electrode material, thus reducing the discharge performance and cycle stability of the battery;

[0101] The embodiments of the present application improve the consistency of primary particles, which is beneficial for the positive electrode particles to have good morphology and evenly bear the stress caused by volume change during positive electrode sintering, reduce particle cracking and breakage, and improve the cycle stability of the battery.

[0102] Furthermore, in the Avizo characterization, 50% of the lengths of the primary particles of the nickel-cobalt-manganese ternary precursor were 420 nm~480 nm, and 50% of the widths were 120 nm~170 nm.

[0103] Furthermore, Avizo software was used to identify and measure the primary particles of the nickel-cobalt-manganese ternary precursor at 30K magnification.

[0104] In some embodiments, the diameter of the crystal nucleus is 1.0 μm~1.5 μm, the thickness of the seed layer is 0.5 μm~1.75 μm, the thickness of the transition layer is 3.0 μm~4.5 μm, and the thickness of the stabilization layer is 1.0 μm~3.0 μm; and / or, in the X-ray diffraction pattern of the nickel-cobalt-manganese ternary precursor, the peak intensity ratio of the 001 peak to the 101 peak I(001) / I(101) is 0.70~1.20.

[0105] The crystal nucleus of the ternary precursor is a non-stable substance in the initial stage of the reaction. If the crystal nucleus is too large, the precursor structure will be unstable and easy to crack; if the crystal nucleus is too small, the stress cannot be effectively released inward during sintering, resulting in cracking of the positive electrode material and affecting the performance. If the seed layer thickness of the ternary precursor is too small, the volume of the crystal nucleus and the transition layer will be too large, which is not conducive to the embedding of lithium ions during sintering; if the seed layer thickness is too large, it will squeeze the transition layer space, which is not conducive to the deintercalation of lithium ions during the cycle process. If the transition layer thickness of the ternary precursor is too small, it will result in too few pores, which is not conducive to the embedding of lithium in the primary particles during sintering; if the transition layer thickness is too large, it will result in too many pores and low particle strength. If the stabilization layer thickness of the ternary precursor is too small, the particle strength is low, and the positive electrode material is easy to break after sintering; if the stabilization layer thickness is too large, it will result in too few pores, which is not conducive to the embedding of lithium in the primary particles during sintering. The thickness of each layer of the ternary precursor crystal nucleus, seed layer, transition layer and stabilization layer provided in the present application is appropriate, which is conducive to improving the electrochemical properties of the positive electrode material.

[0106] The nickel-cobalt-manganese ternary precursor provided in the embodiment of the present application has a peak intensity ratio of 01 peak to 101 peak I(001) / I(101) of 0.70~1.20, which is beneficial to improving the safety performance, cycle performance and specific capacity of the subsequently prepared positive electrode material.

[0107] Furthermore, in the X-ray diffraction pattern of the nickel-cobalt-manganese ternary precursor, the peak intensity ratio of the 001 peak to the 101 peak, I(001) / I(101), is 0.80~1.00.

[0108] Furthermore, the specific surface area of ​​the Ni-Co-Mn ternary precursor is 7 m 2 / g~12 m 2 / g; and / or the tap density of the nickel-cobalt-manganese ternary precursor is 1.85 g / cm 3 ~2.00 g / cm 3 .

[0109] In some embodiments, the nickel-cobalt-manganese ternary precursor has the general chemical formula: Ni x Co y Mn z (OH)2; wherein, 0.80≤x<1, 0≤y<0.10, 0≤z<0.10, x+y+z=1.

[0110] In some embodiments, the above-mentioned preparation method is used to prepare the compound.

[0111] A third aspect of an embodiment of the present application provides a positive electrode material, the raw material being the nickel-cobalt-manganese ternary precursor obtained by the above-mentioned preparation method, or the above-mentioned nickel-cobalt-manganese ternary precursor.

[0112] A fourth aspect of an embodiment of the present application provides a battery, comprising the above-mentioned positive electrode material.

[0113] The following describes the invention in conjunction with specific embodiments.

[0114] Example 1

[0115] This embodiment provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0116] Step 1: Prepare the reaction solution.

[0117] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 92:5:3; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0118] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0119] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0120] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0121] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is continuously reduced to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 3.8 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0122] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0123] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.25, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 70°C.

[0124] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 15 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0125] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth stage reaction began. The flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 15 L / h to 48 L / h; the pH value increased continuously from 10.25 to 10.95, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm; the atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 14.15 μm, the feeding was stopped.

[0126] Step 4: Post-processing.

[0127] The slurry obtained in step 3 is added to the filter pressing washing equipment for washing and filtering, and washed with dilute sodium hydroxide solution and pure water in turn, and then sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a loose and porous ternary precursor with internal pore gradient distribution is obtained.

[0128] Figure 1 The SEM image of the morphology of the ternary precursor obtained in Example 1; Figure 2 This is a primary particle morphology of the nickel-cobalt-manganese ternary precursor provided in Example 1, Figure 3 This is a cross-sectional view of the nickel-cobalt-manganese ternary precursor provided in Example 1.

[0129] Example 2

[0130] This embodiment provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0131] Step 1: Prepare the reaction solution.

[0132] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 92:5:3; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0133] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0134] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0135] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0136] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is continuously reduced to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 3.8 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0137] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0138] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.30, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 70°C.

[0139] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 18 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0140] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth reaction stage was entered, the flow rate of the nickel-cobalt-manganese mixed metal salt solution was continuously increased from 18 L / h to 50 L / h; the pH value was continuously increased from 10.30 to 11.05, and the stirring speed was slowly and continuously decreased from 430 rpm to 172 rpm; the atmosphere, ammonia value and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 14.03 μm, the feeding was stopped;

[0141] Step 4: Post-processing.

[0142] The slurry is added to the filter press washing equipment for washing and filtering, and is washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a loose and porous ternary precursor with internal pore gradient distribution is obtained.

[0143] Figure 4 This is a SEM image showing the morphology of the ternary precursor obtained in Example 2. Figure 4 (a) is the secondary particle morphology. Figure 4 (b) is a primary particle morphology image. Figure 4 (c) is a cross-sectional view.

[0144] Example 3

[0145] This embodiment provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0146] Step 1: Prepare the reaction solution.

[0147] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to form a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 90:5:5; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0148] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0149] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0150] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0151] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is continuously reduced to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 3.5 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0152] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0153] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add 25% sodium hydroxide solution to adjust the pH value of the base liquid to 10.10, add 9% ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 65 °C.

[0154] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 12 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0155] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth reaction stage was entered, the flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 12 L / h to 42 L / h; the pH value increased continuously from 10.10 to 10.80, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm; the atmosphere, ammonia value and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50) reached 13.52 μm, the feeding was stopped;

[0156] Step 4: Post-processing.

[0157] The slurry is added to the filter press washing equipment for washing and filtering, and is washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a loose and porous ternary precursor with internal pore gradient distribution is obtained.

[0158] Figure 5 This is a SEM image showing the morphology of the ternary precursor obtained in Example 3. Figure 5 (a) is the secondary particle morphology. Figure 5 (b) is a primary particle morphology image. Figure 5 (c) is a cross-sectional view.

[0159] Example 4

[0160] This embodiment provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0161] Step 1: Prepare the reaction solution.

[0162] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 92:5:3; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0163] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0164] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0165] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0166] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is lowered to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50) reached 4.5 μm, the feeding was stopped. The slurry was dehydrated and used as seed material for standby use;

[0167] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0168] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.35, add ammonia solution to adjust the ammonia value of the base liquid to 3.3 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 60 °C.

[0169] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 16 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0170] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth reaction stage was entered, the flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 16 L / h to 48 L / h; the pH value increased continuously from 10.35 to 11.00, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm; the atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 13.98 μm, the feeding was stopped.

[0171] Step 4: Post-processing.

[0172] The slurry is added to the filter press washing equipment for washing and filtering, and is washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a loose and porous ternary precursor with internal pore gradient distribution is obtained.

[0173] Example 5

[0174] This embodiment provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0175] Step 1: Prepare the reaction solution.

[0176] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 95:4:1; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0177] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0178] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0179] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0180] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is lowered to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 4.5 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0181] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0182] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.20, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature of 63 °C.

[0183] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 15 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0184] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth stage reaction began. The flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 15 L / h to 48 L / h; the pH value increased continuously from 10.20 to 10.95, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm; the atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 13.92 μm, the feeding was stopped.

[0185] Step 4: Post-processing.

[0186] The slurry is added to the filter press washing equipment for washing and filtering, and is washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a loose and porous ternary precursor with internal pore gradient distribution is obtained.

[0187] Comparative Example 1

[0188] This case provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0189] Step 1: Prepare the reaction solution.

[0190] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 95:4:1; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0191] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0192] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.65, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0193] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0194] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is lowered to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 5.13 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0195] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0196] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.75, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 60 °C.

[0197] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 10 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0198] S33. Fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth reaction stage was entered. The flow rate of the nickel-cobalt-manganese mixed metal salt solution was continuously increased from 10 L / h to 35 L / h. The pH was maintained at 10.75, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm. The atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 13.53 μm, the feeding was stopped.

[0199] Step 4: Post-processing.

[0200] The slurry is added to the filter press washing equipment for washing and filtering, and washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a ternary precursor with a seamless, few-pore connected ring layer and dense structure is obtained.

[0201] Figure 6 This is a SEM image showing the morphology of the ternary precursor obtained in Comparative Example 1. Figure 6 (a) is the secondary particle morphology. Figure 6 (b) is a primary particle morphology image. Figure 6 (c) is a cross-sectional view.

[0202] Comparative Example 2

[0203] This case provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0204] Step 1: Prepare the reaction solution.

[0205] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 95:4:1; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0206] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0207] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.40, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0208] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0209] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is lowered to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50 ) reached 4.58 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0210] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0211] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.85, add ammonia solution to adjust the ammonia value of the base liquid to 3.3 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 60 °C.

[0212] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 10 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0213] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth stage reaction began. The flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 10 L / h to 35 L / h; the pH value increased continuously from 10.85 to 11.05, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm; the atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50) reached 13.98 μm, the feeding was stopped.

[0214] Step 4: Post-processing.

[0215] The slurry is added to the filter press washing equipment for washing and filtering, and is washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a ternary precursor with seamless internal and dense structure is obtained.

[0216] Figure 7 This is a SEM image showing the morphology of the ternary precursor obtained in Comparative Example 2. Figure 7 (a) is the secondary particle morphology. Figure 7 (b) is a primary particle morphology image. Figure 7 (c) is a cross-sectional view.

[0217] Comparative Example 3

[0218] This case provides a nickel-cobalt-manganese ternary precursor, and the specific preparation method is as follows:

[0219] Step 1: Prepare the reaction solution.

[0220] Nickel sulfate, cobalt sulfate, manganese sulfate and pure water were added to prepare a nickel-cobalt-manganese mixed metal salt solution with a concentration of 133 g / L according to a nickel-cobalt-manganese molar ratio of 95:4:1; the precipitant was a sodium hydroxide solution with a mass fraction of 25%, and the complexing agent was an ammonia solution with a mass fraction of 9%.

[0221] Step 2: Prepare nickel-cobalt-manganese ternary precursor seed crystals.

[0222] S21. Prepare the base liquid: introduce N2 as protective gas into the first reactor, add 82.6%L of pure water in the effective volume of the first reactor as the base liquid, add ammonia solution to adjust the ammonia value of the base liquid to 3.0 g / L, add sodium hydroxide solution to adjust the pH value of the base liquid to 11.95, start stirring at 430 rpm, and maintain the reaction temperature at 60 °C.

[0223] S22. First stage reaction: introducing a nickel-cobalt-manganese mixed metal salt solution, a sodium hydroxide solution, and an ammonia solution into the first reaction kettle to carry out a first stage reaction; in the first stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 9 L / h.

[0224] S23. Second stage reaction: 1 h after the first stage reaction, the first stage reaction is completed, the pH is lowered to 11.10, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is increased to 30 L / h, and the stirring speed is controlled at 450 rpm during this period; when D2 (i.e., D v50) reached 4.52 μm, the feeding was stopped and the slurry was dehydrated and used as seed material for standby use.

[0225] Step 3: Prepare nickel-cobalt-manganese ternary precursor.

[0226] S31. Prepare the base liquid: introduce N2 as protective gas into the second reactor, add pure water as the base liquid, put in the seed material prepared in step 2, add sodium hydroxide solution to adjust the pH value of the base liquid to 10.75, add ammonia solution to adjust the ammonia value of the base liquid to 3.3 g / L, start the stirring speed and control it at 430 rpm, and maintain the reaction temperature at 60°C.

[0227] S32. The third stage reaction: Add the nickel-cobalt-manganese mixed metal salt solution, sodium hydroxide solution and ammonia solution into the second reactor to enter the third stage reaction; in the third stage reaction, the flow rate of the nickel-cobalt-manganese mixed metal salt solution is 15 L / h, the ammonia value and pH remain unchanged, and the stirring speed is maintained at 430 rpm.

[0228] S33. The fourth stage reaction: 1 hour after the start of the third stage reaction, the fourth stage reaction began. The flow rate of the nickel-cobalt-manganese mixed metal salt solution increased continuously from 8 L / h to 30 L / h. The pH was maintained at 10.75, and the stirring speed was slowly and continuously reduced from 430 rpm to 172 rpm. The atmosphere, ammonia value, and temperature in the second reactor were maintained unchanged, and the reaction was continued to synthesize the ternary precursor of the slurry. When D3 (i.e., D v50 ) reached 14.11 μm, the feeding was stopped;

[0229] Step 4: Post-processing.

[0230] The slurry is added to the filter press washing equipment for washing and filtering, and washed with dilute sodium hydroxide solution and pure water in turn. After completion, it is sent to the drying process, and then sieved through 325 mesh and demagnetized to obtain the precursor material. That is, a ternary precursor with a seamless, few-pore connected ring layer and dense structure is obtained.

[0231] Figure 8 This is a SEM image showing the morphology of the ternary precursor obtained in Comparative Example 3. Figure 8 (a) is the secondary particle morphology. Figure 8 (b) is a primary particle morphology image. Figure 8 (c) is a cross-sectional view.

[0232] In each preparation method provided in Example 1 to Example 5 and Comparative Example 1 to Comparative Example 3, the preparation parameters are set as shown in Table 1.

[0233] Table 1 Parameters of the preparation methods provided in Examples 1 to 5 and Comparative Examples 1 to 3

[0234]

[0235] Remark:

[0236] 1. In Table 1, 1# represents Example 1, 2# represents Example 2, 3# represents Example 3, 4# represents Example 4, and 5# represents Example 5; D1# represents Comparative Example 1, D2# represents Comparative Example 2, and D3# represents Comparative Example 3.

[0237] 2. In Table 1, the unit of ammonia value is g / L; the unit of stirring speed is rpm; the unit of mixed metal salt solution flow rate is L / h; and the unit of reaction temperature is °C.

[0238] 1. Structural Characterization

[0239] 1. Contrast Figure 1~Figure 4 It can be seen that under the preparation method provided in the present application, the primary whiskers of the precursor prepared have high consistency, and the secondary particles of the precursor have high consistency, compared with the comparative example. Figure 6~Figure 8 Significant improvement.

[0240] 2. As shown in Table 2, the porosity of the ternary precursors provided by Examples 1 to 5 and Comparative Examples 1 to 3 is given.

[0241] Table 2 Porosity of ternary precursors provided in various embodiments and comparative examples

[0242]

[0243] 3. As shown in Table 3, the diameters or thicknesses of each layer of the ternary precursors provided by Examples 1 to 5 and Comparative Examples 1 to 3 are given.

[0244] Table 3 Diameter or thickness of each layer of the ternary precursor provided in each embodiment and each comparative example

[0245]

[0246] 4. As shown in Table 4, the physical and chemical indicators of the ternary precursors provided by Examples 1 to 5 and Comparative Examples 1 to 3 are given.

[0247] Table 4 Physical and chemical indicators of ternary precursors in various embodiments and comparative examples

[0248]

[0249] The test results are shown in Tables 2 to 4. The embodiments of the present application achieve the regulation of the thickness and porosity of different layers of secondary particles and achieve the compatibility of various structural indicators.

[0250] At present, when preparing nickel-cobalt-manganese ternary precursors in the industry, 1) there are technical difficulties in the compatibility of primary particle consistency, internal porosity, and XRD peak intensity ratio. Increasing the pH during the growth stage can improve the consistency of whisker morphology, but the corresponding peak intensity ratio (001 / 101) will increase, and the internal porosity will be lacking. 2) It is difficult to achieve the technical level of K90≤0.35 through conventional technical means. 3) Under high-temperature technology, the precursor XRD peak intensity ratio, crystallinity, and primary particle uniformity are improved, but the porosity will be reduced. 4) There is a lack of high porosity gradient design and related patents.

[0251] In the present application, in the step of preparing the precursor (i.e., step 3), a low pH is first used, and matching the appropriate flow rate of the mixed metal salt solution is conducive to gradually forming a loose internal structure to improve the porosity of the particles; then the pH is increased and the flow rate of the mixed metal salt solution is increased to increase the solid content, which can ensure that the crystallinity of the particles and the XRD peak intensity ratio remain unchanged, while improving the consistency and density of the primary particles, so that the particles grow evenly in stages and layers, thereby improving the strength of the particles.

[0252] When the precursor is prepared by the co-precipitation method, nickel, cobalt and manganese metal ions form crystal nuclei under high pH conditions. The crystal nuclei are close to each other due to hydrogen bonds and van der Waals forces to form agglomerates. At low pH, the advantage of generating crystal nuclei is reduced, and the advantage of crystal growth is dominant. Nickel, cobalt and manganese hydroxide crystals have a growth advantage on the 001 crystal plane and grow preferentially along the C axis. By adopting a process of first lowering the growth pH and then raising the pH, the C-axis growth advantage is controlled to ensure uniform growth of the primary whiskers, thereby ultimately achieving the purpose of improving the consistency of the primary whiskers.

[0253] In addition, by improving the crystallinity of the precursor, cracking and secondary nucleation of the precursor reactants due to collision and other factors during the synthesis process are avoided, thereby improving the consistency of the secondary particles of the finished product and reducing K90.

[0254] In summary, the embodiment of the present application uses low pH in the early stage to match the flow rate of mixed metal solution in the precursor nucleus growth stage to optimize the internal porosity; high pH in the later stage is used to ensure the consistency of whiskers and realize the internal porosity gradient distribution. The peak intensity ratio I(001) / I(101) can be adjusted by the combined influence of the early pH and the later pH values. Through the optimization of the preparation method of the present application, the proportion of small particles in the large-particle precursor product is significantly reduced, thereby reducing K90 and improving the uniformity of product particles.

[0255] 2. Battery performance test

[0256] 1. Test method

[0257] 2000 g of the ternary precursors prepared in Examples 1 to 5 and Comparative Examples 1 to 3 and LiOH·H2O were mixed evenly in a mixer at a molar ratio of 1:1.03, and sintered in a box furnace under air atmosphere at a sintering temperature of 750°C for 12 h. After cooling to room temperature, the ternary precursors were crushed and sieved to obtain a nickel-cobalt-manganese ternary positive electrode material.

[0258] Button cells were used for electrochemical performance testing: the above nickel-cobalt-manganese ternary positive electrode material, conductive carbon black, and binder PVDF (polyvinylidene fluoride) were mixed into a slurry at a ratio of 8:1:1, and coated on aluminum foil to make a positive electrode sheet. The negative electrode sheet used a metal lithium sheet, and the electrolyte used 1 mol / L LiPF6 / EC:DMC (volume ratio 1:1). The battery shell, positive and negative electrode sheets, diaphragms, springs, and gaskets were assembled into button cells in a vacuum glove box. The electrochemical performance test was performed using a blue electric test system. At room temperature, a 0.33 C cycle test was performed for 100 weeks at 3.0 V-4.3 V.

[0259] (II) Test results

[0260] The electrochemical performance test results of the ternary positive electrode materials obtained by sintering the ternary precursors provided in Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 5.

[0261] Table 5 Electrochemical properties of the positive electrodes obtained after sintering the ternary precursors provided in each embodiment and each comparative example

[0262]

[0263] Note: The DCR growth rate is the DCR growth rate of the 100th cycle.

[0264] It can be seen from Table 5 that the embodiment has a significant advantage in DCR growth rate compared to the comparative example, indicating that the battery encapsulated by the precursor material has good stability.

[0265] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a nickel-cobalt-manganese ternary precursor, characterized in that: include: preparing a mixed metal salt solution containing nickel, cobalt and manganese; The mixed metal salt solution is subjected to a first coprecipitation reaction to prepare nickel-cobalt-manganese ternary precursor seed crystals; The first coprecipitation reaction includes a first stage reaction and a second stage reaction in sequence, wherein the pH and the flow rate of the mixed metal salt solution in the second stage reaction are the same or different from those in the first stage reaction; when they are different, the pH of the second stage reaction is lowered and the flow rate of the mixed metal salt solution is increased relative to the first stage reaction; The mixed metal salt solution and the nickel-cobalt-manganese ternary precursor seed crystal are subjected to a second coprecipitation reaction to prepare a nickel-cobalt-manganese ternary precursor; the second coprecipitation reaction includes a third stage reaction and a fourth stage reaction in sequence; the fourth stage reaction is relative to the third stage reaction in that: the pH is increased and the flow rate of the mixed metal salt solution is increased; The fourth stage reaction is relative to the third stage reaction: the pH is increased by 0.5-1.2, and the flow rate of the mixed metal salt solution is increased by 2-5 times.

2. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 1, characterized in that: The pH in the third stage reaction is 9.8-12.0, and the pH in the fourth stage reaction is 10.1-12.3; And / or, the flow rate of the mixed metal salt solution in the third stage reaction is 12 L / h~18 L / h, and the flow rate of the mixed metal salt solution in the fourth stage reaction is 43 L / h~53 L / h.

3. The method for preparing the nickel-cobalt-manganese ternary precursor according to claim 1, characterized in that: During the fourth stage reaction, the stirring speed at the end of the reaction is lower than the stirring speed at the initial stage of the reaction.

4. The method for preparing the nickel-cobalt-manganese ternary precursor according to any one of claims 1 to 3, characterized in that: Compared with the first stage reaction, the pH of the second stage reaction is lowered and the flow rate of the mixed metal salt solution is increased.

5. A nickel-cobalt-manganese ternary precursor, characterized in that: It includes a crystal core and a seed layer, a transition layer and a stabilizing layer which sequentially cover the crystal core; The porosity of the crystal core is 5.0% to 20.0%, the porosity of the seed layer is 1.0% to 6.0%, the porosity of the transition layer is 3.0% to 8.0%, the porosity of the stabilization layer is 2.0% to 5.0%, and the total porosity of the nickel-cobalt-manganese ternary precursor is 3.0% to 6.0%; The volume distribution diameter distance K of the nickel-cobalt-manganese ternary precursor particles 90 ≦0.50; In the Avizo characterization, 50% of the lengths of the nickel-cobalt-manganese ternary precursor primary particles are 400 nm to 500 nm, and 50% of the widths are 100 nm to 180 nm.

6. The nickel-cobalt-manganese ternary precursor according to claim 5, characterized in that: The diameter of the crystal nucleus is 1.0 μm to 1.5 μm, the thickness of the seed layer is 0.5 μm to 1.75 μm, the thickness of the transition layer is 3.0 μm to 4.5 μm, and the thickness of the stabilization layer is 1.0 μm to 3.0 μm; And / or, in the X-ray diffraction pattern of the nickel-cobalt-manganese ternary precursor, the peak intensity ratio of the 001 peak to the 101 peak, I(001) / I(101), is 0.70-1.

20.

7. The nickel-cobalt-manganese ternary precursor according to claim 5 or 6, characterized in that: The preparation method is described in any one of claims 1 to 5.

8. A positive electrode material, characterized in that The raw material includes the nickel-cobalt-manganese ternary precursor obtained by the preparation method described in any one of claims 1-4, or the nickel-cobalt-manganese ternary precursor described in any one of claims 5-7.

9. A battery, characterized in that: Comprising the positive electrode material as claimed in claim 8.

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