Lithium-containing precursor for positive electrode material, preparation method therefor, positive electrode material and lithium secondary battery

Abstract

Provided in the present application are a lithium-containing precursor for a positive electrode material, a preparation method therefor, a positive electrode material and a lithium secondary battery. Said lithium-containing precursor satisfies the chemical formula Lia(NixCoyMn1-x-y)O(1+a), wherein a, x and y are expressed in mol, 0.1≤a≤1.1, 0<x<1, 0<y<1 and x+y<1. Said lithium-containing precursor disclosed by the present application simplifies the production process flow of positive electrode materials by means of directly pre-sintering lithium into the precursor; lithium carbonate decomposing into carbon dioxide is reduced, thus reducing carbon emission; and since lithium is directly pre-sintered into the precursor, the lithium loss rate during sintering the positive electrode material is reduced, thus increasing the yield of finished products under the same bowl loading amount and greatly increasing the production capacity of production lines. In addition, no excessive wastewater will be generated during the sintering of said lithium-containing precursor of the present application. Therefore, said lithium-containing precursor provided by the present application is more economical and more environment-friendly than traditional precursors.

Description

Positive electrode material containing lithium precursor and preparation method thereof, positive electrode material, and lithium secondary battery

[0001] This application claims priority to Chinese Patent Application No. 202310756035.7 filed on June 25, 2023, and the contents of the above-mentioned Chinese patent application disclosure are hereby incorporated by reference in their entirety as a part of this application. Technical Field

[0002] The present invention relates to the technical field of lithium battery materials, and in particular to a lithium-containing precursor of a positive electrode material and a preparation method thereof, a positive electrode material, and a lithium secondary battery. Background Art

[0003] With the rapid development of new energy vehicles, the demand for power batteries is increasing, and at the same time, it is also facing greater challenges, especially the more stringent conditions for the performance of positive electrode materials. In power batteries, the positive electrode material precursor products are made of nickel salts, cobalt salts, and manganese salts. The ratio of nickel, cobalt, and manganese can be adjusted according to actual needs. At present, most of the public positive electrode material precursor products are hydroxides. The mainstream preparation technology is: dissolving nickel salts, manganese salts, and cobalt salts to form a mixed solution, mixing it with ammonia water and alkali solution, and through the complexation effect of ammonia water and the co-precipitation effect of alkali solution, after the crystal nucleus is formed, the crystal continues to grow by agglomeration to obtain a ternary positive electrode hydroxide precursor.

[0004] Currently, the production of ternary cathode hydroxide precursors is difficult due to the difficulty of process control, which can easily affect product stability. Furthermore, power batteries account for a significant portion of the cost of new energy vehicles, and cathode materials contribute over 60% of the battery cell cost. The industry has long sought to reduce the cost of producing cathode materials. Environmental issues in the lithium battery industry are receiving increasing attention, and the industry is also looking to reduce wastewater and waste generated by cathode material production. However, the production of hydroxide precursors during cathode material production produces wastewater, which is detrimental to the environment. Furthermore, hydroxide precursors contain lower primary metal content of nickel, cobalt, manganese, and lithium. Therefore, when hydroxide precursors are used to prepare cathode materials, the final product yield is lower at the same loading rate.

[0005] Therefore, there is still a need to develop a new cathode material containing lithium precursor and / or cathode material and production process.

[0006] Summary of the Invention

[0007] The present inventors have developed a lithium-containing precursor of a positive electrode material and a preparation method thereof, a positive electrode material and a lithium secondary battery through intensive research and development, thereby overcoming one or more of the above-mentioned deficiencies of the prior art.

[0008] The first aspect of the present application provides a positive electrode material containing lithium precursor, which satisfies the chemical formula Li a (Ni x Coy Mn 1-x-y )O (1+a) , wherein a, x, y are expressed in mol, 0.10≤a≤1.1, 0<x<1, 0<y<1 and x+y<1.

[0009] The lithium-containing precursor of the positive electrode material disclosed in the present application is an oxide lithium-containing precursor. When the lithium-containing precursor is sintered into a positive electrode material, no wastewater is generated due to the absence of hydroxide. The lithium-containing precursor exists in the form of an oxide. Compared with traditional hydroxide precursors, the oxide precursor has a higher content of main metals such as nickel, cobalt and manganese. At the same time, the precursor also contains lithium. When sintered into a positive electrode material, the loss rate of lithium during sintering of the positive electrode material is reduced, and the yield of finished products under the same loading amount is increased, thereby increasing the output when sintering into a positive electrode material, reducing the manufacturing cost of the positive electrode material, and greatly increasing the production line capacity.

[0010] A second aspect of the present application provides a method for preparing a lithium-containing precursor of a positive electrode material, comprising the following steps:

[0011] preparing a mixed solution of lithium nitrate, nickel nitrate, cobalt nitrate and manganese nitrate;

[0012] The mixed solution is subjected to atomization and calcination treatment to obtain a positive electrode material lithium-containing precursor. The temperature of the atomization and calcination treatment is 300° C.-1000° C. The positive electrode material lithium-containing precursor is the positive electrode material lithium-containing precursor described above.

[0013] Since the preparation method prepares the aforementioned lithium-containing precursor, the preparation method of the lithium-containing precursor also inherits the technical effect of the lithium-containing precursor; at the same time, the lithium-containing precursor in the present application is formed by atomization roasting. Compared with the hydroxide precursor prepared by the coprecipitation method, the process of the present application is simple, with fewer intermediate processes, and the reaction process is convenient for flexible regulation. The roasting treatment is carried out while atomizing, which not only ensures that the product has a smaller particle size, but also the product has a fast reaction speed. The actual reaction time of obtaining the lithium-containing precursor material by atomization roasting is only a few seconds, and the production efficiency is high. In addition, since the anions in the salt solution are converted into gaseous substances in a high temperature environment and removed or recycled, the raw material utilization rate is high, the impurity content in the product is low, and the performance is excellent. At the same time, the lithium-containing precursor material product prepared by this method has a more excellent structural stability of the material itself relative to the traditional coprecipitation method.

[0014] The third aspect of the present application provides a positive electrode material, which is sintered from the aforementioned positive electrode material precursor. During sintering, the temperature is directly raised to the maximum sintering temperature, and sintering is performed at the maximum sintering temperature to obtain the positive electrode material. The maximum sintering temperature is 300°C-1000°C.

[0015] Since the positive electrode material is sintered from the aforementioned lithium-containing precursor, the positive electrode material also inherits the technical effects of the lithium-containing precursor; when the hydroxide precursor is used to prepare the positive electrode material, the positive electrode hydroxide precursor usually needs to be mixed with a lithium source in a solid state and then sintered at a high temperature. However, due to the uneven mixing between solids and the slow diffusion rate of lithium in the solid phase, it may be difficult to evenly distribute the lithium. The uneven distribution of lithium will seriously affect the electrochemical properties of the positive electrode material. When the lithium-containing precursor of the present application is used to prepare the positive electrode material, since the lithium-containing precursor itself has lithium, when preparing the positive electrode material, only a small amount of lithium source needs to be added or no lithium source needs to be added to directly sinter it into the positive electrode material, so that the distribution of lithium is more uniform, thereby improving the electrochemical properties of the positive electrode material. On the other hand, by directly pre-burning lithium into the precursor, the subsequent mixing process of the precursor and the lithium source is reduced, and the production process of the positive electrode material is simplified; relative to the traditional precursor and lithium carbonate sintering process, the decomposition of lithium carbonate into carbon dioxide is reduced, and carbon emissions are reduced; due to the direct pre-burning of lithium into the precursor, the temperature of the lithium-containing precursor of the present application when sintering the positive electrode material is lower than the temperature of the traditional precursor when sintering the positive electrode material under the same conditions, so the sintering cost can be reduced. On the other hand, since the positive electrode material precursor suppliers and lithium source suppliers are usually independent of each other, the downstream positive electrode material manufacturers need to strictly control the product quality and batch stability of the positive electrode material precursor suppliers and lithium source suppliers, which is difficult, which is not conducive to the stability of the positive electrode material preparation. The lithium-containing precursor of the present application itself has lithium, therefore, to a certain extent, it solves the raw material supply problem of the positive electrode material manufacturer and improves the stability of the positive electrode material preparation.

[0016] A fourth aspect of the present application provides a lithium secondary battery, wherein the positive electrode sheet of the secondary battery includes the above-mentioned positive electrode material.

[0017] Since the lithium secondary battery contains the aforementioned positive electrode material, the lithium secondary battery also inherits the technical effects of the positive electrode material. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present invention, but are not intended to limit the present invention.

[0019] FIG1 is a SEM photograph of the lithium-containing precursor of the positive electrode material of Example 1 of the present disclosure at a magnification of 1000.

[0020] FIG2 is a SEM photograph of the lithium-containing precursor of the positive electrode material of Example 1 of the present disclosure at a magnification of 10.0K.

[0021] FIG3 is a SEM photograph of the lithium-containing precursor of the positive electrode material of Example 1 of the present disclosure at a magnification of 50.0K.

[0022] FIG4 is an XRD spectrum of the lithium-containing precursor of the positive electrode material of Example 1 of the present disclosure.

[0023] FIG5 is a SEM photograph of the positive electrode material of Example 1 of the present disclosure at a magnification of 20.0K.

[0024] FIG6 is an XRD spectrum of the positive electrode material of Example 1 of the present disclosure. DETAILED DESCRIPTION

[0025] The present invention may be implemented in other specific forms without departing from the essential attributes of the present invention. It should be understood that, without conflict, any and all embodiments of the present invention may be combined with the technical features of any other embodiment or multiple other embodiments to produce additional embodiments. The present invention includes additional embodiments resulting from such combinations.

[0026] All publications and patents mentioned in this disclosure are hereby incorporated into the present disclosure in their entirety by reference. If the purposes or terms used in any publications and patents incorporated by reference conflict with the purposes or terms used in this disclosure, then the purposes and terms of this disclosure shall prevail.

[0027] The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described.

[0028] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as those commonly used in the art to which the claimed subject matter belongs. If there are multiple definitions for a term, the definition herein shall prevail.

[0029] Except in the working examples or otherwise indicated, all numbers stating quantitative properties such as particle size in the specification and claims should be understood to be modified in all instances by the term "about". It should also be understood that any numerical range recited herein is intended to include all subranges within that range and any combination of the various endpoints of that range or subrange.

[0030] As used in this disclosure, words such as "include," "comprising," or "including" mean that the elements preceding the word include the elements listed after the word and their equivalents, without excluding unlisted elements. The terms "comprising" or "including" as used herein may be open, semi-closed, or closed. In other words, the terms also include "consisting essentially of" or "consisting of."

[0031] The term "optionally" in this disclosure means that the described circumstances may or may not occur.

[0032] The term "positive electrode material precursor" in this disclosure refers to the substance before the high-temperature sintering step in the preparation of the positive electrode material (hereinafter sometimes referred to as "precursor" or "precursor"). The term "positive electrode material lithium-containing precursor" refers to the aforementioned positive electrode material precursor containing lithium.

[0033] Unless otherwise specified, the term "Li" does not refer to Li metal alone but to the Li element. The same applies to other elements such as Ni, Co, and Mn.

[0034] <Lithium-containing precursor for positive electrode materials>

[0035] One embodiment of the present application is a lithium-containing precursor for a positive electrode material. The precursors in the prior art do not contain lithium. When preparing the precursor into a positive electrode material, the precursor must first be mixed with a lithium source. The precursor and the lithium source are then placed in a roasting furnace for sintering, allowing the lithium in the lithium source to be incorporated into the molecular structure to form the positive electrode material. However, the lithium-containing precursor of the present application contains lithium. When preparing the positive electrode material from the lithium-containing precursor, no additional lithium source or a small amount of additional lithium source is required to sinter the positive electrode material.

[0036] The lithium-containing precursor in this application is represented by the following general formula: Li a (Ni x Co y Mn 1-x-y )O (1+a)··· (I) The general formula satisfies that a, x, and y are expressed in mol, 0.10≤a≤1.1, 0<x<1, 0<y<1, and x+y<1.

[0037] From the perspective of being able to obtain a lithium secondary battery with a high reversible capacity, x in the above composition formula (I) is preferably 0.5 or more, more preferably 0.55 or more, and particularly preferably 0.8 or more. In addition, from the perspective of being able to obtain a lithium secondary battery with a higher initial charge and discharge efficiency, it is preferably less than 1.0, more preferably 0.95 or less, and particularly preferably 0.9 or less.

[0038] The upper limit and lower limit of x may be arbitrarily combined. For example, x is preferably 0.4 or more and less than 1.0, more preferably 0.50 or more and 0.90 or less, and even more preferably 0.55 or more and 0.80 or less.

[0039] Specifically, x can be selected as 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, etc.

[0040] In addition, from the perspective of obtaining a lithium secondary battery with low battery resistance, y in the above composition formula (I) is preferably 0.01 or more, more preferably 0.05 or more. In addition, from the perspective of obtaining a lithium secondary battery with high thermal stability, y is preferably 0.40 or less, more preferably 0.19 or less, and even more preferably 0.09 or less.

[0041] The upper limit and lower limit of y may be arbitrarily combined. For example, y is preferably greater than 0 and 0.40 or less, more preferably 0.01 or more and 0.29 or less, and even more preferably 0.01 or more and 0.09 or less.

[0042] Specifically, y can be selected as 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, etc.

[0043] In addition, from the perspective of obtaining a lithium secondary battery with high thermal stability, 1-xy in the above composition formula (I) is preferably 0.01 or greater, more preferably 0.05 or greater. In addition, from the perspective of obtaining a lithium secondary battery with high storage characteristics at high temperatures (e.g., 60°C), 1-xy in the above composition formula (I) is preferably 0.40 or less, more preferably 0.19 or less, and even more preferably 0.18 or less.

[0044] Specifically, 1-xy can be selected as 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, etc.

[0045] In addition, from the perspective of shortening the process and improving the finished product yield under the same loading amount, a in the above-mentioned composition formula (I) is preferably more than 0.1, more preferably more than 0.50, and further preferably more than 1.0. In addition, from the perspective of maintaining a lithium secondary battery with high cycle performance, a in the above-mentioned composition formula (I) is preferably less than 1.2, more preferably less than 1.1, and further preferably less than 1.08.

[0046] Specifically, the value range of a is 1<a≤1.08. In this way, the lithium-containing precursor of the positive electrode material can be sintered to prepare a ternary positive electrode active material without being mixed with another lithium source. This reduces the process of mixing the precursor with the lithium source, thereby reducing costs. At the same time, since the lithium-containing precursor already has sufficient lithium, when sintering into a positive electrode material, the loss rate of lithium can be reduced, and the yield of the finished product under the same loading amount can be improved. In a more preferred embodiment, the value of a in (I) is 1.01~1.06. This can further reduce the loss rate of lithium when the precursor is sintered into a positive electrode material, and improve the yield of the finished product under the same loading amount.

[0047] If 0.10≤a≤0.50, then when preparing the precursor, recycled materials from used lithium batteries can be used. Recycled materials contain a small amount of lithium, and using this recycled material as the raw material to prepare the lithium-containing precursor can reduce the lithium loss rate and lower production costs. If 0.50≤a≤1.00, then when preparing the positive electrode material, only a small amount of lithium source needs to be added. The positive electrode material prepared using the lithium-containing precursor within this range has less free lithium, which is beneficial to improving the electrochemical performance of the positive electrode material.

[0048] Specifically, a can be selected from 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0. 33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.5 8, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, 0.70, 0.71, 0.72, 0.73, 0.74, 0.75, 0.76, 0.77, 0.78, 0.79, 0.80, 0.81, 0.82, 0.83 , 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.90, 0.91, 0.92, 0.93, 0.94, 0.95, 0.96, 0.97, 0.98, 0.99, 1.00, 1.01, 1.02, 1.03, 1.04, 1.05, 1.06, 1.07, 1.08, etc.

[0049] By regulating the ratio of each metal element in the lithium-containing precursor, the lithium secondary battery has a higher initial charge and discharge efficiency, and the finished product yield is improved under the same loading amount, making the product preparation process simpler and the product performance having higher thermal stability.

[0050] For example, you can choose

[0051] Li 0.50 (Ni 0.55 Co 0.23 Mn 0.22 )O 1.5 、Li 0.50 (Ni 0.60 Co 0.10 Mn 0.30 )O 1.5 、

[0052] Li 0.50 (Ni 0.67 Co 0.05 Mn 0.28 )O 1.5 、Li 0.50 (Ni 0.80 Co 0.10 Mn 0.10 )O1.5 、

[0053] Li 0.50 (Ni 0.77 Co 0.13 Mn 0.10 )O 1.5 、Li 0.50 (Ni 0.90 Co 0.05 Mn 0.05 )O 1.5 、

[0054] Li 0.70 (Ni 0.55 Co 0.23 Mn 0.22 )O 1.7 、Li 0.60 (Ni 0.60 Co 0.10 Mn 0.30 )O 1.6 、

[0055] Li 0.30 (Ni 0.67 Co 0.05 Mn 0.28 )O 1.3 、Li 0.40 (Ni 0.80 Co 0.10 Mn 0.10 )O 1.4 、

[0056] Li 1.02 (Ni 0.77 Co 0.13 Mn 0.10 )O 2.02 、Li 1.08 (Ni 0.90 Co 0.05 Mn 0.05 )O 2.08 wait.

[0057] [Composition Analysis]

[0058] The composition analysis of the lithium-containing precursor is to add the obtained lithium-containing precursor powder into a 100mL beaker, add 6mL of hydrochloric acid and 2mL of nitric acid for digestion, filter after cooling (if necessary), and dilute to a 250mL volumetric flask, use a 5mL large-bellied pipette to take 5mL and transfer it to a 100mL volumetric flask, add 2mL of nitric acid, dilute to volume, and use Thermo Fisher ICP-OES to test the content of Li, Ni, Co, Mn, etc.

[0059] In a first aspect, the present disclosure provides a lithium-containing precursor for a positive electrode material, wherein the lithium-containing precursor material comprises lithium nickel cobalt manganese oxide. The lithium-containing precursor for the positive electrode material is essentially composed of lithium nickel cobalt manganese oxide. In one embodiment, the total weight of lithium nickel cobalt manganese oxide in the lithium-containing precursor for the positive electrode material accounts for more than 98.0% by weight of the lithium-containing precursor material, for example, more than 99.0% by weight, more than 99.1% by weight, more than 99.2% by weight, more than 99.3% by weight, more than 99.4% by weight, more than 99.5% by weight, more than 99.6% by weight, more than 99.7% by weight, more than 99.8% by weight, or more than 99.9% by weight.

[0060] The lithium-containing precursor of the positive electrode material disclosed in the present application is an oxide lithium-containing precursor. When the lithium-containing precursor is sintered into a positive electrode material, no wastewater is generated due to the absence of hydroxide. The lithium-containing precursor exists in the form of an oxide. Compared with traditional hydroxide precursors, the oxide precursor has a higher content of main metals such as nickel, cobalt and manganese. At the same time, the precursor also contains lithium. When sintered into a positive electrode material, the loss rate of lithium during sintering of the positive electrode material is reduced, and the yield of the finished product under the same loading amount is increased, thereby increasing the output when sintering into the positive electrode material, reducing the manufacturing cost of the positive electrode material, and greatly increasing the production line capacity.

[0061] In one embodiment, the lithium-containing precursor of the positive electrode material includes at least one sheet-like agglomerate formed by agglomeration of primary particles.

[0062] It should be noted that the lithium-containing precursor may include multiple flaky agglomerates. For example, the lithium-containing precursor includes 2 flaky agglomerates, 3 flaky agglomerates, 4 flaky agglomerates, etc. The number of flaky agglomerates in the embodiments of this application is not specifically limited.

[0063] For example, through SEM observation, the positive electrode material containing lithium precursor after the sphere is crushed is irregular flake-shaped, and the maximum thickness of the flake agglomerate is 0.1-10 μm, the maximum length is 0.1-30 μm, and the maximum width is 0.1-30 μm. In order to improve the electrode density when the positive electrode for lithium secondary batteries is made, the volume capacity density is increased, and preferably, the maximum thickness of the flake agglomerate is 0.2-8 μm, the maximum length is 1.0-18 μm, and the maximum width is 1.0-18 μm. In order to further improve the electrode density when the positive electrode for lithium secondary batteries is made, the volume capacity density is increased, and more preferably, the maximum thickness of the flake agglomerate is 2-5 μm, the maximum length is 3-10 μm, and the maximum width is 3-10 μm. Specifically, the maximum thickness of the flake aggregates can be selected to be 0.1 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, etc. The maximum length of the flake aggregates can be selected to be 0.1 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 30 μm, etc. Specifically, the maximum width of the flake aggregates can be selected to be 0.1 μm, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 8 μm, 10 μm, 15 μm, 20 μm, 30 μm, etc.

[0064] When the lithium-containing precursor of the present application is used as a raw material to manufacture a positive electrode material, since crystal growth is not excessive, the movement resistance of lithium ions is not easy to increase. When the precursor of the present application is used to manufacture a positive electrode material, it is easy to form a state in which lithium ions are evenly distributed in the particles. The lithium ion conductivity of such a positive electrode material is easily improved. When using such a positive electrode material, the cycle maintenance rate of a lithium secondary battery can be improved.

[0065] Conventional ternary hydroxide precursor materials are usually spherical or quasi-spherical when observed through SEM after the spheres are broken.

[0066] In the present application, the term "primary particles" refers to particles that appear to have no grain boundaries when observed at a viewing angle of 5,000 to 20,000 times using a scanning electron microscope or the like.

[0067] In the present application, the term "agglomerates" refers to particles formed by the aggregation of the primary particles described above, and flake-like agglomerates further refers to particles having a flake-like or substantially flake-like shape.

[0068] [SEM measurement]

[0069] The morphology of the material was observed using a tungsten filament scanning electron microscope (VEGA LMS) manufactured by Tescan. SEM observations were performed using an electron beam with an accelerating voltage of 10 keV and a working distance of 5 mm.

[0070] In one embodiment, the positive electrode material containing lithium precursor is a flaky agglomerate, which is formed by agglomerating multiple primary particles of less than 500 nanometers. In order to increase the electrode density when making a positive electrode for a lithium secondary battery and increase the volume capacity density, it is preferred that the primary particles are less than 300 nanometers, and more preferably, the primary particles are less than 200 nanometers and greater than 100 nanometers. Specifically, the particle size of the primary particles is 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, or 450nm.

[0071] Primary particles are less than 500nm, and there are few interfaces between the primary particles, so the particles of the positive electrode material are not easy to crack during charging and discharging. The positive electrode material produced by using the lithium-containing precursor of this embodiment as a raw material is not easy to generate resistance, thus, it can improve the cycle retention rate of the lithium secondary battery.

[0072] The XRD pattern of the lithium-containing precursor of the cathode material disclosed herein has no diffraction peak at 31.7±0.3 degrees 2θ, which is believed to indicate that the precursor material does not contain lithium carbonate or has a very low lithium carbonate content.

[0073] In one embodiment, the XRD of the lithium-containing precursor of the positive electrode material has diffraction peaks at 2θ=18.7±0.3, 2θ=36.5±0.3, 2θ=37.9±0.3, 2θ=44.1±0.3, 2θ=48.4±0.3, 2θ=58.3±0.3, 2θ=64.2±0.3, and 2θ=67.9±0.3 degrees.

[0074] In the lithium-containing precursor of the present application, in the powder X-ray diffraction pattern using Cu-Kα rays, there are diffraction peaks at 2θ=48.4±0.3, 2θ=58.3±0.3, and 2θ=67.9±0.3 degrees, indicating that lithium has been pre-burned into the lithium-containing precursor in the present application. Since the lithium-containing precursor already has lithium, when the lithium-containing precursor is used to prepare the positive electrode material, the process of mixing the precursor with the lithium source is reduced, and the production of the positive electrode material is simplified. Production process flow; compared with the traditional precursor and lithium carbonate sintering process, the decomposition of lithium carbonate into carbon dioxide is reduced, thereby reducing carbon emissions; since lithium is directly pre-burned into the precursor, the lithium loss rate during the sintering of the positive electrode material is reduced, thereby improving the finished product yield under the same loading amount and greatly increasing the production line capacity; in addition, when the lithium-containing precursor in the present application is sintered, the temperature when the lithium-containing precursor in the present application is used to sinter the positive electrode material is lower than that of the traditional precursor under the same conditions, thereby reducing the sintering cost.

[0075] [Powder X-ray diffraction measurement]

[0076] In this specification, powder X-ray diffraction measurement can be measured by an X-ray diffractometer. As an X-ray diffractometer, for example, Ultima IV can be used.

[0077] Specifically, the powder of the lithium precursor is filled into a dedicated substrate, and a Cu-Kα ray source is used to measure the powder X-ray diffraction spectrum under the conditions of a diffraction angle of 2θ = 10° to 90°, an operating voltage of 40 kV, a sampling amplitude of 0.002°, and a scanning speed of 5° / min.

[0078] The powder X-ray diffraction pattern of the lithium-containing precursor of the positive electrode material using Cu-Kα rays shows that the precursor has a layered structure.

[0079] From the obtained X-ray diffraction spectrum, peaks within the ranges of 2θ=18.7±0.3, 2θ=36.5±0.3, 2θ=37.9±0.3, 2θ=44.1±0.3, 2θ=48.4±0.3, 2θ=58.3±0.3, 2θ=64.2±0.3, and 2θ=67.9±0.3 were confirmed.

[0080] In one embodiment, in the powder X-ray diffraction pattern of the positive electrode material lithium-containing precursor using Cu-Kα radiation, the ratio of the half-peak width α of the peak at 18.7±0.3 degrees 2θ to the half-peak width β of the peak at 44.1±0.3 degrees 2θ is 0.8 to 1.8.

[0081] The upper limit value and the lower limit value of the half-width ratio (α / β) can be arbitrarily combined.

[0082] For example, the half-value width ratio (α / β) is preferably 0.9 or more and 1.6 or less, and more preferably 1.2 or more and 1.5 or less.

[0083] For example, in the powder X-ray diffraction pattern of the lithium-containing precursor of the positive electrode material using Cu-Kα rays, the ratio of the half-width α of the peak at 18.7±0.3 degrees 2θ to the half-width β of the peak at 44.1±0.3 degrees 2θ is 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, etc.

[0084] In the present embodiment, it is believed that if (α / β) is within the above-mentioned specific range, when the lithium-containing precursor is sintered into a positive electrode material, the particles grow regularly. Therefore, it can be inferred that the positive electrode material prepared by the lithium-containing precursor of the present application can improve the initial charge and discharge efficiency when used in a lithium secondary battery. At the same time, after the lithium-containing precursor having α / β satisfying the above-mentioned specific range is prepared into a positive electrode material, the cycle maintenance rate of the lithium secondary battery can be improved due to the small movement resistance of the lithium ions accompanying charging and discharging.

[0085] In some embodiments, the half-peak width α ranges from 0.50 to 0.70 degrees, and the half-peak width β ranges from 0.30 to 0.50 degrees. The upper and lower limits of α and β can be arbitrarily combined.

[0086] For example, α is preferably 0.51 to 0.69, more preferably 0.55 to 0.65, and even more preferably 0.58 to 0.63. β is preferably 0.30 to 0.50, more preferably 0.31 to 0.48, and even more preferably 0.35 to 0.45.

[0087] For example, α can be selected as 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69, and 0.70 degrees, and β can be selected as 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, and 0.50 degrees.

[0088] In this embodiment, it is believed that if α and β are within the above-mentioned specific ranges, when the lithium-containing precursor is sintered into a positive electrode material, the particles grow regularly. Therefore, it can be inferred that the positive electrode material prepared from the lithium-containing precursor of the present application can improve the initial charge and discharge efficiency when used in a lithium secondary battery. At the same time, after the lithium-containing precursor with α and β satisfying the above-mentioned specific ranges is prepared into a positive electrode material, the cycle retention rate of the lithium secondary battery can be improved due to the low movement resistance of the lithium ions accompanying charging and discharging.

[0089] In this embodiment, the half-value width α of the peak existing in the range of diffraction angle 2θ = 18.7 ± 0.3° (hereinafter sometimes referred to as "peak A") and the half-value width β of the peak existing in the range of 2θ = 44.1 ± 0.3° (hereinafter sometimes referred to as "peak B") can be calculated by the following method. First, the precursor is subjected to powder X-ray diffraction measurement using Cu-Kα as a radiation source and the measurement range of the diffraction angle 2θ is set to 10° or more and 90° or less, and Peak A and Peak B are determined. Next, the profile of each diffraction peak is approximated by a Gaussian function, and the difference in 2θ between the two points where the value of the second differential curve is zero is multiplied by the coefficient 2ln2 (≈1.386) to calculate the half-value width α and the half-value width β (for example, refer to "The Reality of Powder X-ray Analysis - An Introduction to the Rietveld Method", 7th edition, published on June 20, 2006, by Izumi Nakai and Fujio Izumi).

[0090] In a preferred embodiment, the peak intensity of the peak at 18.7±0.3 degrees 2θ in the powder X-ray diffraction pattern using Cu-Kα radiation is 1 a , the peak intensity at 44.1±0.3 degrees 2θ is Ib, I a with I b The peak intensity ratio is greater than 0.2 and less than 1.

[0091] Peak intensity ratio (I a / I b ) The upper and lower limits can be combined arbitrarily.

[0092] For example, the peak intensity ratio (I a / I b ) is preferably 0.22 or more and 0.99 or less, more preferably 0.30 or more and 0.95 or less, and further preferably 0.7 or more and 0.9 or less.

[0093] Specifically, I a / I b You can choose 0.25, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8 or 0.9, etc.

[0094] In this embodiment, the peak at 18.7±0.3 degrees 2θ is generally considered to be the (003) peak, and the peak at 44.1±0.3 degrees 2θ is generally considered to be the (104) peak. The ratio of the two peak intensities can reflect the degree of cation mixing of the material. Generally, the higher the I(003) / I(104) value, the lower the cation mixing degree in the lattice. Excessive cation mixing will hinder Li + Deintercalation leads to Li + The diffusion coefficient decreases and the electrochemical performance of the material decreases. The I(003) / I(104) value of the positive electrode material is usually significantly higher than 1.2, indicating that it has a lower cation mixing. The peak intensity I of the peak at 18.7±0.3 degrees 2θ of the lithium-containing precursor of the positive electrode material is a Less than the peak intensity I of the peak at 44.1±0.3 degrees 2θ b , therefore, the ratio of the two is less than 1, indicating that the lithium-containing nickel-cobalt-manganese positive electrode precursor has a higher cation mixing than the nickel-cobalt-manganese positive electrode material, and sintering is required to reduce the cation mixing. After the lithium-containing precursor of the present application is used to prepare the positive electrode material, the I(003) / I(104) value of the positive electrode material is usually significantly higher than 1.2. Therefore, it can be inferred that the positive electrode material prepared by the lithium-containing precursor of the present application can improve the initial charge and discharge efficiency when used in lithium secondary batteries. Satisfying the above I a / I b When a lithium-containing precursor within a specific range is prepared into a positive electrode material, cation mixing is reduced, and the cycle retention rate of the lithium secondary battery can be improved.

[0095] In one embodiment, the XRD peak of the positive electrode material containing lithium precursor at 18.7±0.3 degrees 2θ has a half-peak width of 0.50-0.70 degrees, for example, 0.59 degrees, and the half-peak width of the peak at 44.1±0.3 degrees 2θ is 0.30-0.50 degrees, for example, 0.41 degrees. The XRD pattern of the positive electrode material containing lithium precursor has a small half-peak width at the peak at 18.7±0.3 degrees 2θ and the peak at 44.1±0.3 degrees 2θ, indicating a good peak shape and good crystallinity, but the half-peak width is greater than the half-peak width of the corresponding nickel-cobalt-manganese positive electrode material, which indicates that the crystallinity of the positive electrode material containing lithium precursor is still not as good as that of the nickel-cobalt-manganese positive electrode material.

[0096] In one embodiment, the ratio of the tap density (TBD) to the bulk density (LBD) of the lithium-containing precursor of the positive electrode material is greater than 2.

[0097] The upper and lower limits of the ratio of tap density (TBD) to bulk density (LBD) can be arbitrarily combined.

[0098] From the viewpoint of being able to obtain a lithium secondary battery with a high electrode density, for example, (TBD / LBD) is preferably greater than 2. The value of TBD / LBD has no upper limit, but if the relationship between TBD and LBD becomes unbalanced, the particle shape becomes more uneven, or the filling property of the particle deteriorates. In this case, when the lithium-containing precursor is prepared into a positive electrode material, the electrode density of the lithium secondary battery is further affected.

[0099] The lower limit of the TBD / LBD ratio of the lithium-containing precursor is 2, preferably 2.1, more preferably 2.5, further preferably 2.8, and more preferably 3. The upper limit of the TBD / LBD ratio of the lithium-containing precursor is not particularly limited, but the upper limit is preferably 8, more preferably 6. For example, the TBD / LBD ratio of the lithium-containing precursor may be in the range of 2 to 8, or in the range of 2.3 to 5.1.

[0100] For example, TBD / LBD is 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0.

[0101] In this embodiment, from the viewpoint of obtaining a lithium secondary battery with a high electrode density, the tap density of the lithium-containing precursor is preferably 0.8 g / cm 3 More than 1.2 g / cm 3 Above, particularly preferably 1.4 g / cm 3In addition, from the perspective of increasing the unit potting volume, thereby increasing the output when sintering into a positive electrode material and reducing the manufacturing cost of the positive electrode material, it is preferably 2.5g / cm 3 Below, more preferably 2.0 g / cm 3 Below, particularly preferably 1.9 g / cm 3 the following.

[0102] The upper and lower limits of the tap density can be arbitrarily combined. For example, the tap density is preferably 1.0 g / cm 3 Above and 2.2g / cm 3 Below, more preferably 1.2 g / cm 3 Above and 2.0g / cm 3 Below, more preferably 1.4 g / cm 3 Above and 1.9g / cm 3 the following.

[0103] In this embodiment, from the viewpoint of obtaining a lithium secondary battery with a high electrode density, the bulk density of the lithium-containing precursor is preferably 0.4 or more, more preferably 0.41 g / cm 3 Above, particularly preferably 0.45 g / cm 3 In addition, from the perspective of increasing the unit potting volume, thereby increasing the output when sintering into a positive electrode material and reducing the manufacturing cost of the positive electrode material, it is preferably 0.9 g / cm 3 Below, more preferably 0.8g / cm 3 Below, particularly preferably 0.7 g / cm 3 the following.

[0104] The upper and lower limits of the bulk density can be arbitrarily combined. For example, the bulk density is preferably 0.41 g / cm 3 Above and 0.88g / cm 3 Below, more preferably 0.45g / cm 3 Above and 0.85g / cm 3 Below, more preferably 0.5 g / cm 3 Above and 0.7g / cm 3 the following.

[0105] The lithium-containing precursor of the positive electrode material disclosed in the present application has a larger loose density and tap density. When sintered into a positive electrode material, the unit filling amount is increased, thereby increasing the output when sintering into the positive electrode material and reducing the manufacturing cost of the positive electrode material.

[0106] [Determination of tap density]

[0107] Use a 25 mL graduated cylinder to fill 23-25 ​​mL of the lithium-containing precursor sample, weigh the mass of the sample, vibrate at a frequency of 250 times / min with an amplitude of 3 mm, read the volume of the sample after vibrating 3000 times, and calculate the tap density.

[0108] [Determination of bulk density]

[0109] The Scott volumetric method was used to allow the lithium-containing precursor powder to pass through a series of inclined baffles in the Scott volumetric meter to fill a volume of 25 cm 3 The mass of the lithium-containing precursor sample is weighed in a cylindrical cup, and the ratio of mass to volume is calculated as the bulk density.

[0110] In one embodiment, the D90 / D10 value of the lithium-containing precursor of the positive electrode material, determined from a particle size distribution measurement, is 4 or more and 12 or less.

[0111] In this embodiment, the ratio of the 90% cumulative volume particle size D90 to the 10% cumulative volume particle size D10 (D90 / D10) of the lithium-containing precursor is 4.0 or greater. In this embodiment, D90 / D10 is preferably 4.1 or greater, more preferably 4.5 or greater, and particularly preferably 5 or greater. The upper limit of D90 / D10 is not particularly limited, but as an example, it is 12 or less, preferably 8 or less.

[0112] The upper limit and lower limit of D 90 / D 10 may be arbitrarily combined. For example, D 90 / D 10 is 4.0 to 12.0, preferably 4.0 to 10.0, more preferably 4.5 to 9.0, and particularly preferably 5.0 to 8.0.

[0113] [Cumulative volume particle size was measured by laser diffraction scattering method]

[0114] A laser particle size analyzer (Malvern, model: Mastersizer 3000) was used to test. A small amount of sample was added to 20 mL of 10% sodium hexametaphosphate solution, subjected to external ultrasound for 2-5 minutes, and then added to the particle size analyzer for testing to obtain a cumulative volume particle size distribution curve.

[0115] Then, in the cumulative particle size distribution curve obtained, the value of the particle size observed from the fine particle side at the time of accumulation of 10% is the 10% cumulative volume particle size D10 (μm), the value of the particle size observed from the fine particle side at the time of accumulation of 90% is the 90% cumulative volume particle size D90 (μm), and the value of the particle size observed from the fine particle side at the time of accumulation of 50% is the 50% cumulative volume particle size D50 (μm).

[0116] In some embodiments, the D90 is 5 to 40 μm, and the D10 is 0.5 to 8 μm.

[0117] The lithium-containing precursor preferably has a 90% cumulative volume particle size D90 of 5-40 μm, more preferably 5.5-35 μm, and even more preferably 6-30 μm. When the lithium-containing precursor has a 90% cumulative volume particle size D90 within the range of 5-40 μm, the positive electrode material prepared from the lithium-containing precursor is less likely to crack at the intergranular interface due to lithium ion insertion and deinsertion reactions, even during repeated charge and discharge of the lithium secondary battery, thereby improving the cycle retention rate of the lithium secondary battery.

[0118] For example, D90 can be selected as 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, 30μm, 31μm, 32μm, 33μm, 34μm, 35μm, 36μm, 37μm, 38μm, 39μm, 40μm.

[0119] D10 can be selected as 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 10μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, and 8μm.

[0120] The 10% cumulative volume particle size D10 of the lithium-containing precursor is preferably 0.5-8 μm, more preferably 0.6-7.8 μm, and even more preferably 0.7-6.6 μm. When the 10% cumulative volume particle size D10 of the lithium-containing precursor is within the range of 0.5-8 μm, the positive electrode material prepared from the lithium-containing precursor is less likely to crack at the intergranular interface due to lithium ion insertion and deinsertion reactions, even during repeated charge and discharge of the lithium secondary battery, thereby improving the cycle retention rate of the lithium secondary battery.

[0121] In some embodiments, the D90 / D50 value of the lithium-containing precursor of the positive electrode material, obtained from a particle size distribution measurement, is 1.5 to 5.

[0122] In this embodiment, the ratio of the 90% cumulative volume particle size D90 to the 50% cumulative volume particle size D50 (D90 / D50) of the lithium-containing precursor is 1.5 or greater. In this embodiment, D90 / D50 is preferably 1.6 or greater, more preferably 2 or greater, and particularly preferably 2.1 or greater. The upper limit of D90 / D50 is not particularly limited, but as an example, it can be 5 or less, preferably 4.5 or less.

[0123] The upper limit and lower limit of D 90 / D 50 may be arbitrarily combined. For example, D 90 / D 50 is 1.5 to 5.0, preferably 1.6 to 4.8, more preferably 2 to 4.5, and particularly preferably 2.1 to 4.0.

[0124] When the lithium-containing precursor having a D 90 / D 50 value within the above specific range is prepared into a positive electrode material, irreversible reactions can be easily suppressed, thereby improving the cycle retention rate of the lithium secondary battery.

[0125] The 50% cumulative volume particle size D50 of the lithium-containing precursor is preferably 1.0-15 μm, more preferably 1.2-14 μm, and even more preferably 1.5-12 μm. When the 50% cumulative volume particle size D50 of the lithium-containing precursor is within the range of 1.0-15 μm, the positive electrode material prepared from the lithium-containing precursor is less likely to crack at the intergranular interface associated with lithium ion insertion and deinsertion reactions, even during repeated charge and discharge of the lithium secondary battery. As a result, the cycle retention rate of the lithium secondary battery can be improved.

[0126] For example, D 50 can be chosen to be 1.0 μm, 1.2 μm, 1.5 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm.

[0127] In some embodiments, the ratio of the specific surface area of ​​the lithium-containing precursor of the positive electrode material to D50 is 3 × 10 6 ~15×10 6 m / g.

[0128] In the lithium-containing precursor of this embodiment, the specific surface area is S, and the ratio of the specific surface area to the 50% cumulative volume particle size D50 is S / D50, and S / D50 is 3×10 6 ~15×10 6 m / g, preferably 3.5×10 6 ~12×10 6 m / g, more preferably 3.8×10 6 ~10×10 6 m / g, more preferably 4.0×10 6 ~8×10 6 m / g, particularly preferably 5.0×10 6 m / g or more and less than 7.8×10 6 m / g. If S / D50 is 3×10 6 m / g or more, it can be said that the lithium-containing precursor is not excessively crystallized. 6 m / g or less, the primary particles contained in the lithium-containing precursor aggregate at an appropriate density.

[0129] If S / D50 is 3×10 6 ~15×10 6 m / g of lithium-containing precursor to produce the positive electrode material, a positive electrode material with a large area involved in the insertion and extraction of lithium ions and high discharge rate characteristics of the lithium secondary battery can be obtained.

[0130] For example, S / D50 can be selected as 3×10 6 m / g, 4×10 6 m / g, 5×10 6 m / g, 6×10 6 m / g, 7×10 6 m / g, 8×10 6 m / g, 9×10 6 m / g, 10×10 6 m / g, 11×10 6 m / g, 12×10 6 m / g, 13×10 6 m / g, 14×10 6 m / g, 15×10 6 m / g.

[0131] In some embodiments, the BET specific surface area of ​​the lithium-containing precursor of the positive electrode material is 2 to 20 m 2 The upper limit value and the lower limit value of the BET specific surface area can be arbitrarily combined.

[0132] In the lithium-containing precursor of this embodiment, the BET specific surface area of ​​the lithium-containing precursor is preferably 2 to 20 m 2 / g, more preferably 3 to 18m 2 / g, more preferably 4 to 15m 2 / g. If the BET specific surface area of ​​the precursor is 2 to 20m 2 / g, the primary particles contained in the lithium-containing precursor aggregate at an appropriate density. Therefore, if such a lithium-containing precursor is used to produce a positive electrode material, a positive electrode material with high discharge rate characteristics for lithium secondary batteries can be obtained.

[0133] For example, the BET surface area of ​​the lithium-containing precursor of the positive electrode material is 2 m 2 / g、3m 2 / g、4m 2 / g、5m 2 / g、6m 2 / g、7m 2 / g、8m 2 / g、9m 2 / g、10m 2 / g、11m 2 / g、12m 2 / g、13m 2 / g、14m 2 / g、15m 2 / g、16m 2 / g、17m 2 / g、18m 2 / g、19m 2 / g, 20m 2 / g.

[0134] [Measurement of specific surface area]

[0135] A 2.5 g sample of the lithium-containing precursor was heated in vacuum at 200°C for 1 h and measured using a BET surface area analyzer (Mic, USA, model: Tristar II 3030).

[0136] In some embodiments, the positive electrode material contains less than 500 ppm of calcium ions in the lithium precursor.

[0137] In the lithium-containing precursor of this embodiment, the calcium ion content in the lithium-containing precursor is more preferably 400 ppm or less / g, and further preferably 300 ppm or less. Generally, there is no lower limit for the calcium ion content in the lithium-containing precursor. Considering the production cost of impurity removal, the calcium ion content in the lithium-containing precursor may be 20 ppm or more. More preferably, the calcium ion content in the lithium-containing precursor is 100 ppm or more.

[0138] The upper limit and lower limit of calcium ions in the lithium-containing precursor can be arbitrarily combined. For example, the content of calcium ions in the lithium-containing precursor is more than 20ppm and less than 480ppm, preferably more than 50ppm and less than 400ppm, more preferably more than 100ppm and less than 300ppm. Compared with the precursors in the prior art, the impurity content of impurity calcium in the embodiment of the present application may be higher, but calcium generally has little effect on the performance of the product, and if this impurity is to be removed, then an additional impurity removal process is required, and even new additives need to be introduced, which undoubtedly increases the cost. After the lithium-containing precursor with the calcium ion content in the lithium-containing precursor being within the above-mentioned specific range is prepared into a positive electrode material, it can maintain the discharge rate characteristics of a high lithium secondary battery while reducing costs.

[0139] In some embodiments, the content of magnesium ions in the lithium-containing precursor of the positive electrode material is less than 500 ppm.

[0140] In the lithium-containing precursor of the present embodiment, the magnesium ion content in the lithium-containing precursor is more preferably 400 ppm or less / g, and further preferably 300 ppm or less. Generally, the lower limit of the magnesium ion content in the lithium-containing precursor is not limited. Considering the production cost of impurities removal, the lithium content of the magnesium ion in the lithium-containing precursor may be 20 ppm or more. More preferably, the magnesium ion content in the lithium-containing precursor is 100 ppm or more.

[0141] The upper limit and lower limit of the magnesium ion in the lithium-containing precursor can be arbitrarily combined. For example, the content of magnesium ions in the lithium-containing precursor is more than 20ppm and less than 480ppm, preferably more than 50ppm and less than 400ppm, more preferably more than 100ppm and less than 300ppm. Compared with the precursor in the prior art, the impurity content of magnesium in the embodiment of the present application may be higher, and if this impurity is to be removed, then an additional impurity removal process is required, and even new additives need to be introduced, which undoubtedly increases the cost. After the lithium-containing precursor with the magnesium ion content in the lithium-containing precursor being within the above-mentioned specific range is prepared into a positive electrode material, it is possible to maintain the discharge rate characteristics of a high lithium secondary battery while reducing costs.

[0142] In some embodiments, the sulfate content in the lithium-containing precursor of the positive electrode material is less than 50 ppm.

[0143] In the lithium-containing precursor of this embodiment, the sulfate content in the lithium-containing precursor is 50 ppm or less, more preferably 45 ppm or less. Generally, there is no lower limit for the sulfate content in the lithium-containing precursor. Considering the production cost of impurity removal, the sulfate content in the lithium-containing precursor can be 5 ppm or more.

[0144] The upper and lower limits of the sulfate content in the lithium-containing precursor can be arbitrarily combined. For example, the sulfate content in the lithium-containing precursor is 1 ppm to 48 ppm, preferably 2 ppm to 45 ppm, and more preferably 5 ppm to 40 ppm.

[0145] At present, the ternary precursor uses sulfate as the main metal raw material, adopts the coprecipitation method, and nickel salt, cobalt salt, and manganese salt are mixed into salt solution in a certain proportion, and a metal hydroxide system or a metal carbonate system precursor is formed under the action of a precipitant and a chelating agent, and a qualified product is obtained by washing, filtering, drying and other processes. During the coprecipitation reaction, sulfate radical mainly exists in the mother liquor in the form of sodium sulfate. A large amount of sulfate radical will be adsorbed on the surface or inside of the crystal, and it is necessary to wash with pure water to reduce the sulfur content. Part of the sulfate radical remaining inside the crystal will become an impurity in the positive electrode material, affecting the capacity and cycle performance of the positive electrode material, causing the overall performance of the battery to decline. The lithium-containing precursor of the present application has extremely low sulfate radical impurities, which will not affect the capacity and cycle performance of the positive electrode material, and improve the overall performance of the battery.

[0146] In some embodiments, the sodium ion content in the lithium-containing precursor of the positive electrode material is below 50 ppm.

[0147] In the lithium-containing precursor of this embodiment, the sodium ion content in the lithium-containing precursor is 50 ppm or less, more preferably 45 ppm or less, further preferably 30 ppm or less, and further preferably 10 ppm or less.

[0148] The lithium-containing precursor of the present application has extremely low sodium ion impurities, which prevents sodium ions from affecting the capacity and cycle performance of the positive electrode material, thereby improving the overall performance of the battery.

[0149] In some embodiments, the contents of hydrochloride, phosphate, and oxalate in the lithium-containing precursor of the positive electrode material are each below 100 ppm.

[0150] In the lithium-containing precursor of this embodiment, the contents of hydrochloride, phosphate, and oxalate in the lithium-containing precursor are each 100 ppm or less, more preferably 80 ppm or less, more preferably 60 ppm or less, and even more preferably 50 ppm or less.

[0151] The lithium-containing precursor of the present application has extremely low hydrochloride, phosphate, and oxalate, which prevents these impurity ions from affecting the capacity and cycle performance of the positive electrode material, thereby improving the overall performance of the battery.

[0152] [Determination of metal ion content]

[0153] Thermo Fisher ICP-OES was used for testing (instrument manufacturer: Thermo Fisher, model: ICAPPROX).

[0154] Impurity test: Add a small amount of lithium-containing precursor sample to a 100mL beaker, add 6mL hydrochloric acid and 2mL nitric acid, digest, cool and filter (if necessary), and dilute to a 100mL volumetric flask to test the metal ion content in the lithium-containing precursor.

[0155] [Determination of chloride ion content]

[0156] Weigh 1g of lithium-containing precursor sample, wet the sample with water, add concentrated nitric acid and hydrogen peroxide, and dissolve the sample under stirring and boiling conditions. The Cl in the sample - With H + Generate volatile HCl, use a sealed container and a catheter to absorb the volatilized HCl with ultrapure water, and use a potentiometric titrator (silver nitrate standard titration solution) to test the Cl absorbed in the ultrapure water. - content.

[0157] [Determination of carbon or sulfur composition]

[0158] Carbon or sulfur was measured using a Wanlianda CS-901B high-frequency infrared carbon and sulfur analyzer (instrument manufacturer: Wanlianda, model: CS-901B6). Impurity testing: Heat a ceramic crucible at 900°C for 4 hours and then cool to room temperature. Test three sets of standard samples for calibration. Then, weigh 0.4±0.01g of iron flux into the crucible. After returning to zero, weigh a certain amount of lithium-containing precursor sample and add a spoonful of tungsten pellets. Run the lithium-containing precursor sample on the analyzer, click Analyze, and output the data.

[0159] In some embodiments, the crystal structure of the lithium-containing precursor of the positive electrode material is a layered structure.

[0160] After the positive electrode material is formed using the lithium-containing precursor of the present application, the hexagonal layered structure is a two-dimensional structure, which is conducive to the intercalation and deintercalation of lithium ions, thereby increasing the specific capacity of the positive electrode material.

[0161] In some embodiments, the crystal form of the lithium-containing precursor of the positive electrode material is one or more of a spinel structure, a cubic structure, and an octahedral structure.

[0162] The cubic structure helps improve the uniformity of lithium-containing precursor materials, reduces agglomeration, improves product stability, and enhances cycle performance and rate performance. Lithium-containing precursors with an octahedral structure have a high active surface area, which is also beneficial for lithium ion deintercalation and extraction. The high particle size uniformity of the precursor particles helps improve the density, flatness, and uniformity of the cathode film, thereby improving the battery's cycle stability. The spinel structure is a three-dimensional cubic structure with high crystal structural stability, which helps improve the cycle stability and rate performance of the cathode material.

[0163] In some embodiments, the positive electrode material contains a lithium precursor with a charge and discharge voltage of 3.0 to 4.4 V and a first discharge capacity of 150 mAh / g or less at 0.1C.

[0164] Compared with traditional precursors, the lithium-containing precursor in the embodiment of the present application already has lithium, so lithium can be deintercalated for charging and discharging. Therefore, the lithium-containing precursor in the embodiment of the present application has a higher first efficiency than the traditional precursor. However, since the crystal structure of the lithium-containing precursor in the embodiment of the present application has not yet been fully formed, the lithium-containing precursor in the embodiment of the present application has a lower first efficiency than the positive electrode material and cannot be directly used as the positive electrode material of a lithium secondary battery. However, the lithium-containing precursor in the embodiment of the present application also contains lithium. When sintered into a positive electrode material, the loss rate of lithium during sintering of the positive electrode material is reduced, and the yield of the finished product under the same loading amount is increased, thereby increasing the output when sintered into a positive electrode material, reducing the manufacturing cost of the positive electrode material, and greatly increasing the production line capacity.

[0165] In the lithium-containing precursor of this embodiment, the lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 v and a 0.1C first discharge capacity of 150 mAh / g or less. More preferably, the lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 v and a 0.1C first discharge capacity of 120 mAh / g or less. Still more preferably, the lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 v and a 0.1C first discharge capacity of 100 mAh / g or less. Still further, the lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 v and a 0.1C first discharge capacity of 70 mAh / g or less. The lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 V and a first discharge capacity of 0.1 C of more than 10 mAh / g. Furthermore, the lithium-containing precursor has a charge and discharge voltage of 3.0 to 4.4 V and a first discharge capacity of 0.1 C of more than 20 mAh / g.

[0166] The upper and lower limits of the capacitance of the lithium-containing precursor at a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge can be arbitrarily combined. For example, the capacitance of the lithium-containing precursor at a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge is below 120 mAh / g and above 5 mAh / g; the capacitance of the lithium-containing precursor at a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge is below 110 mAh / g and above 10 mAh / g; the capacitance of the lithium-containing precursor at a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge is below 70 mAh / g and above 20 mAh / g.

[0167] In the embodiment of the present application, after the lithium-containing precursor with a charge and discharge voltage of 3.0 to 4.4V and a capacitance value of 0.1C first discharge is prepared into a positive electrode material in the above-mentioned specific range, the capacitance value of the charge and discharge voltage of 3.0 to 4.4V and 0.1C first discharge can be significantly improved, so that the discharge rate characteristics of the lithium secondary battery are good while reducing costs.

[0168] <Power-off test>

[0169] [Charge and discharge test]

[0170] A half-cell was fabricated using the lithium-containing precursor described above. After initial charge and discharge, a discharge rate test and a cycle test were performed to evaluate the discharge rate characteristics and the cycle characteristics.

[0171] The battery's ambient temperature is controlled at 25.0°C ± 0.2°C. The first charge and discharge at 4.4V 0.1C and the first efficiency test are divided into four steps:

[0172] 1. Let the prepared half-cell stand for ≥12h;

[0173] 2. Charge at a rate of 0.1C, ending when the voltage is ≥ 4.4V;

[0174] 3. Constant voltage charging, the end condition is current ≤ 50μA;

[0175] 4. Discharge rate 0.1C, end condition: voltage ≤ 3V.

[0176] First efficiency = first discharge capacity (mAh / g) ÷ first charge capacity (mAh / g) × 100.

[0177] [Measurement method of cycle maintenance rate]

[0178] [Cycle test]

[0179] Using coin-type batteries, follow the cycle test conditions shown below.

[0180] Test temperature: 25℃, charge and discharge steps are as follows:

[0181] 1. Let it stand for ≥12h;

[0182] 2. Charge at a rate of 0.1C, ending when the voltage is ≥ 4.4V;

[0183] 3. Constant voltage charging, the end condition is current ≤ 50μA;

[0184] 4. Discharge rate 0.1C, end condition: voltage ≤ 3V.

[0185] Steps 1 to 4 constitute one cycle, and the charge and discharge steps 2 to 4 were repeated 49 times, for a total of 50 cycles. Lifespan evaluation was conducted through 50 cycles, and the discharge capacity retention rate after 50 cycles was calculated using the following formula. A higher discharge capacity retention rate after 50 cycles indicates better high-voltage cycling characteristics.

[0186] Discharge capacity retention rate after 50 cycles (%) = 50th discharge capacity / 1st discharge capacity × 100. The discharge capacity retention rate after 50 cycles may be referred to herein as “cycle retention rate”.

[0187] The lithium-containing precursor of the positive electrode material disclosed in the present application is an oxide lithium-containing precursor. When the lithium-containing precursor is sintered into a positive electrode material, no wastewater is generated due to the absence of hydroxide. The lithium-containing precursor exists in the form of an oxide. Compared with traditional hydroxide precursors, the oxide precursor has a higher content of main metals such as nickel, cobalt and manganese. At the same time, the precursor also contains lithium. When sintered into a positive electrode material, the loss rate of lithium during sintering of the positive electrode material is reduced, and the yield of the finished product under the same loading amount is increased, thereby increasing the output when sintering into the positive electrode material, reducing the manufacturing cost of the positive electrode material, and greatly increasing the production line capacity.

[0188] The second aspect of the present disclosure provides a method for preparing a lithium-containing precursor material for a positive electrode material, according to Li a (Nix Co y Mn 1-x-y )O (1+a) The stoichiometric ratio of the metal elements in the chemical formula is obtained by mixing lithium nitrate, nickel nitrate solution, cobalt nitrate solution, and manganese nitrate solution, and then controlling the concentration of lithium salt, nickel salt, cobalt salt, and manganese salt in the mixed solution by concentration treatment; the mixed solution is subjected to atomization and calcination treatment, and while the mixed solution is atomized into fine droplets, the atomized droplets are directly calcined, so that the metal cations such as lithium, nickel, cobalt, and manganese in the droplets react rapidly in a high-temperature environment to form an oxide-containing lithium precursor, while the anions in the salt solution are converted into gaseous substances such as nitrogen oxides in a high-temperature environment and removed or recovered, thereby obtaining a positive electrode precursor material with high product purity, small particle size, and good uniformity. The preparation method has a simple process flow, few intermediate processes, and the reaction process is easy to flexibly control. The calcination treatment is carried out while atomizing, which not only ensures that the product has a smaller particle size, but also a fast product reaction speed. The actual reaction time of the lithium-containing positive electrode material obtained by atomization and calcination is only a few seconds, and the production efficiency is high. In addition, since the anions in the salt solution are converted into gaseous substances in a high-temperature environment and removed or recovered, the raw material utilization rate is high, the impurity content in the product is low, and the performance is excellent.

[0189] The present invention discloses a method for directly preparing a positive electrode precursor material by atomizing and calcining a mixed solution, which is beneficial to improving the structural stability of the precursor material, increasing the density of the precursor material, and refining the particle size of the material, thereby further improving the unit loading amount of the precursor material, improving the preparation efficiency of the positive electrode material, and reducing the manufacturing cost. Compared with the traditional method of preparing a ternary hydroxide precursor by coprecipitation method, etc., it not only improves the preparation efficiency of the material, simplifies the process, reduces the discharge of industrial waste such as wastewater, and makes the production process more environmentally friendly and reduces the production cost; it is also more conducive to regulating the crystal structure, particle size, bulkiness, density and other properties of the precursor material, overcoming the problems of poor structural stability, low density, and poor controllability of particle size in the existing secondary crystallization-coated ternary hydroxide precursor material.

[0190] In some embodiments, a nitrate solution containing lithium, nickel, cobalt, and manganese is transferred to a mixing tank for mixing to prepare a mixed solution containing lithium, nickel, cobalt, and manganese ions, wherein the mixing tank is made of an acid-resistant material with a certain strength.

[0191] In some embodiments, after mixing the lithium salt solution, nickel salt solution, cobalt salt solution, and manganese salt solution, a concentration treatment is performed to control the total concentration of lithium salt, nickel salt, cobalt salt, and manganese salt in the obtained mixed solution to be 50 to 300 g / L. Such a metal salt concentration is conducive to atomization crystallization and granulation. If the total concentration of the metal salts in the mixed solution is lower than 50 g / L, the metal salt content in the droplets after atomization is too low, which is not conducive to the full reaction and crystallization of the metal salts in the droplets during the roasting process, resulting in less product and not conducive to the enrichment of the precursor; if the total concentration of the metal salts in the mixed solution is higher than 300 g / L, the metal salt content in the droplets after atomization is too high, which is not conducive to the crystallization and granulation of the metal salt components during the roasting process, and the particle size is too large, which is not conducive to the preparation of single crystal materials and the regulation of the material crystal form, thereby reducing the stability of the positive electrode precursor. In some specific embodiments, the total concentration of lithium salt, nickel salt, cobalt salt and manganese salt in the mixed solution is 50 g / L, 60 g / L, 80 g / L, 120 g / L, 160 g / L, 200 g / L, 220 g / L, 260 g / L, 300 g / L, etc.

[0192] In some embodiments, the step of atomizing and roasting the mixed solution includes: performing spray pyrolysis in a spray dryer, wherein the air-to-coal ratio (air to natural gas flow ratio) of the roaster burner is 8.5-20:1, for example, 12, 15, etc.; atomization parameters include: compressed air pressure ≥ 0.2 MPa, for example, 0.2-0.5 MPa; compressed air to liquid flow volume ratio of 50-300:1; and controlling the pyrolysis temperature to 300-1000° C., for example, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, or 1000° C. In some embodiments, the pyrolysis temperature is controlled to be 700-900° C. Higher pyrolysis temperatures result in higher energy consumption. The nitrate solution is atomized in a spray dryer to form droplets. Under the action of hot air, the droplets rapidly lose water, and the nitrate undergoes thermal decomposition and conversion into oxides. The nanoparticles in the droplets agglomerate to form large agglomerates, which are the precursor powder. During the spray pyrolysis process, the nanoscale primary particles aggregate into micron-sized agglomerates, which helps increase the compaction density of the lithium nickel cobalt manganese oxide positive electrode material produced after calcination, thereby increasing the volume energy density of the lithium nickel cobalt manganese oxide positive electrode material as a lithium-ion battery electrode material. By adjusting the burner air-to-coal ratio, compressed air pressure, and the volume ratio of compressed air to liquid flow during the atomization and roasting process, the particle size, crystal form and other physical properties of the prepared positive electrode precursor material can be flexibly controlled, thereby helping to optimize the physicochemical properties of the positive electrode material.

[0193] In some embodiments, the calcination time is controlled to be 1 to 50 seconds. In this process, a shaped lithium-containing precursor can be prepared in a short time, which has a short preparation time and high efficiency, and is conducive to wide application.

[0194] In some embodiments, after the lithium-containing precursor material is prepared, post-processing steps such as grinding or crushing the lithium-containing precursor material are also included. By controlling conditions such as the grinding disc spacing or the crushing gas pressure flow rate, the particle size of the obtained product can be controlled, making the particle size distribution of the positive electrode precursor material more uniform.

[0195] The preparation method provided in the embodiment of the present application prepares the aforementioned lithium-containing precursor. Therefore, the preparation method of the lithium-containing precursor also inherits the technical effect of the lithium-containing precursor. At the same time, the lithium-containing precursor in the present application is formed by atomization roasting. Compared with the hydroxide precursor prepared by the coprecipitation method, the process flow of the present application is simple, with few intermediate processes, and the reaction process is convenient for flexible regulation. The roasting treatment is carried out while atomizing, which not only ensures that the product has a smaller particle size, but also the product reaction speed is fast. The actual reaction time of obtaining the lithium-containing precursor material by atomization roasting is only a few seconds, and the production efficiency is high. In addition, since the anions in the salt solution are converted into gaseous substances in a high temperature environment for removal or recycling, the raw material utilization rate is high, the impurity content in the product is low, and the performance is excellent. At the same time, the lithium-containing precursor material product prepared by this method has a more excellent structural stability of the material itself relative to the traditional coprecipitation method.

[0196] A third aspect of the present disclosure provides a positive electrode material, which is obtained by sintering the aforementioned positive electrode material lithium-containing precursor material, or by mixing the lithium-containing precursor and a supplementary lithium source (a small amount of lithium source is supplemented based on the lithium content in the lithium-containing precursor relative to the lithium content lacking in the positive electrode material) and then sintering. The lithium source can be selected from one or more of lithium carbonate, lithium hydroxide monohydrate, lithium acetate, lithium nitrate, lithium oxalate, lithium acetate, lithium hydroxide, and lithium oxide. For example, the lithium source is selected from lithium carbonate or lithium hydroxide monohydrate.

[0197] In some preferred embodiments, the positive electrode material is obtained by directly sintering the positive electrode precursor material without mixing the positive electrode precursor material with a lithium source.

[0198] Sintering can be performed in a pure oxygen or air atmosphere, with a sintering frequency of 1-3 times, at a temperature of 300-1000°C. For example, the sintering process is performed once, comprising heating the cathode precursor material to 750-1000°C at a heating rate of 5-10°C / min, maintaining the temperature at this temperature for 9-18 hours, and then naturally cooling to room temperature. The sintered product is sieved through a 300-mesh screen to obtain the lithium nickel cobalt manganese oxide cathode material.

[0199] For example, the cathode material that can be provided in the third aspect of the present disclosure is selected from NCM333, NCM523, NCM613, NCM622 and NCM811. Preferably, the cathode material is a high nickel cathode material, including but not limited to: LiNi 0.72 Co 0.03 Mn 0.25 O2、LiNi 0.7 Co 0.04 Mn 0.26 O2、LiNi 0.67 Co 0.05 Mn 0.28 O2、LiNi 0.65 Co 0.06 Mn 0.29 O2、LiNi 0.62 Co 0.08 Mn 0.30 O2、LiNi 0.6 Co 0.10 Mn 0.30 O2, etc. These positive electrode materials also have the characteristics of good structural stability, high capacity, and good cycle stability.

[0200] Since the positive electrode material is prepared from the aforementioned lithium-containing precursor, the positive electrode material also inherits the technical effects of the lithium-containing precursor; when the hydroxide precursor is used to prepare the positive electrode material, the positive electrode hydroxide precursor usually needs to be mixed with a lithium source for solid state and then sintered at high temperature. However, due to the uneven mixing between solids and the slow diffusion rate of lithium in the solid phase, it may be difficult to evenly distribute the lithium. The uneven distribution of lithium will seriously affect the electrochemical properties of the positive electrode material. When the lithium-containing precursor of the present application is used to prepare the positive electrode material, since the lithium-containing precursor itself has lithium, when preparing the positive electrode material, only a small amount of lithium source needs to be added or no lithium source needs to be added to directly sinter it into the positive electrode material, so that the distribution of lithium is more uniform, thereby improving the electrochemical properties of the positive electrode material. On the other hand, by directly pre-burning lithium into the precursor, the subsequent mixing process of the precursor and the lithium source is reduced, and the production process of the positive electrode material is simplified; relative to the traditional precursor and lithium carbonate sintering process, the decomposition of lithium carbonate into carbon dioxide is reduced, and carbon emissions are reduced; due to the direct pre-burning of lithium into the precursor, the temperature of the lithium-containing precursor of the present application when sintering the positive electrode material is lower than the temperature of the traditional precursor when sintering the positive electrode material under the same conditions, so the sintering cost can be reduced. On the other hand, since the positive electrode material precursor suppliers and lithium source suppliers are usually independent of each other, the downstream positive electrode material manufacturers need to strictly control the product quality and batch stability of the positive electrode material precursor suppliers and lithium source suppliers, which is difficult, which is not conducive to the stability of the positive electrode material preparation. The lithium-containing precursor of the present application itself has lithium, therefore, to a certain extent, it solves the raw material supply problem of the positive electrode material manufacturer and improves the stability of the positive electrode material preparation.

[0201] A fourth aspect of the present application provides a lithium secondary battery, wherein the positive electrode sheet of the lithium secondary battery includes the above-mentioned positive electrode material.

[0202] The lithium secondary battery provided in the fourth aspect of the present application includes the above-mentioned positive electrode material in the positive electrode sheet. The positive electrode material has high gram capacity, cycle stability, structural stability and other characteristics, thereby improving the energy density, cycle stability, and safety performance of the secondary battery.

[0203] In some embodiments, the positive electrode sheet in the lithium secondary battery includes a current collector and an active material layer that are laminated and bonded together, and the active material layer includes a ternary material, a conductive agent, a binder, and the like.

[0204] In some embodiments, the process of preparing the positive electrode material into a positive electrode sheet is as follows: mixing the positive electrode material, a conductive agent and a binder to obtain an electrode slurry, coating the electrode slurry on a current collector, and preparing the positive electrode sheet through steps such as drying, rolling, and die cutting.

[0205] In some embodiments, the positive electrode current collector includes but is not limited to any one of copper foil and aluminum foil.

[0206] In some embodiments, the content of the binder in the electrode slurry is 2wt%-4wt%. The binder may include one or more of polyvinylidene chloride, soluble polytetrafluoroethylene, styrene-butadiene rubber, hydroxypropyl methylcellulose, methylcellulose, carboxymethyl cellulose, polyvinyl alcohol, acrylonitrile copolymer, sodium alginate, chitosan, and chitosan derivatives. In some embodiments, the content of the conductive agent in the electrode slurry is 3wt%-5wt%. The conductive agent may include one or more of graphite, carbon black, acetylene black, graphene, carbon fiber, C60, and carbon nanotubes.

[0207] The present disclosure does not specifically limit the negative electrode sheet, electrolyte, separator, etc. in the lithium secondary battery and is applicable to conventional lithium-ion battery systems.

[0208] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the embodiments of the present invention are clearly and completely described below. The embodiments described below are exemplary and are only used to explain the present invention, and are not to be understood as limiting the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0209] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods. Unless otherwise specified, the materials, reagents, etc. used in the following examples are all commercially available.

[0210] Example 1

[0211] Experiment 1.1: Preparation of Lithium-containing Precursors for Cathode Materials

[0212] A nitrate solution of nickel, cobalt, manganese, and lithium was prepared according to a molar ratio of Ni:Mn:Co:Li = 0.60:0.10:0.30:1.05, wherein the total concentration of nickel nitrate, cobalt nitrate, manganese nitrate, and lithium nitrate was 175 g / L;

[0213] The solution is introduced into a synthesis tower for spray pyrolysis, with powder discharged from the bottom. The powder is cooled in a cooler before being screened, pneumatically crushed, demagnetized, and packaged as finished products. Flue gas is drawn from the top by a fan, where it passes through a Venturi to scrub dust and cool the flue gas. The exhaust gas then passes through a heat exchanger to reduce its temperature to less than 30°C. The exhaust then undergoes multi-stage absorption to recover nitric acid, and finally undergoes alkaline washing and urea absorption to ensure that the exhaust meets emission standards.

[0214] Spray pyrolysis parameters: burner air-to-coal ratio (ratio of air and natural gas flow): 14:1;

[0215] Atomization parameters: compressed air pressure: 0.3MPA;

[0216] Compressed air and liquid flow volume ratio: 175:1;

[0217] The temperature of the spray pyrolysis was 750° C., and the calcination treatment time was 10 seconds.

[0218] The SEM images are shown in Figures 1 to 3, and the XRD spectrum is shown in Figure 4.

[0219] The chemical formula of the lithium-containing precursor is Li 1.05 (Ni 0.60 Co 0.10 Mn 0.30 )O 2.05 The positive electrode material lithium-containing precursor includes a plurality of sheet-like agglomerates formed by agglomeration of primary particles, the primary particles are 150 nm, the maximum thickness of the agglomerates is 5 μm, the maximum length is 18 μm, the maximum width is 15 μm, and the peak intensity of the peak at 18.7 ± 0.3 degrees 2θ in the powder X-ray diffraction pattern using Cu-Kα radiation is I a The peak intensity of the peak at 44.1±0.3 degrees 2θ is I b , I a with I b The peak intensity ratio is 0.6. The lithium-containing precursor has a layered structure. The tap density of the lithium-containing precursor is 1.59 g / cm 3 , the bulk density is 0.53g / cm 3The ratio of tap density to bulk density is 3, the D90 / D10 value of the lithium-containing precursor obtained from the particle size distribution measurement value is 7, the D50 of the lithium-containing precursor obtained from the particle size distribution measurement value is 3.3 μm, and the BET specific surface area is 7.1 m 2 The magnesium ion content is 300 ppm, the calcium ion content is 400 ppm, and the sulfate content in the lithium-containing precursor is 48 ppm.

[0220] Experiment 1.2: Preparation of positive electrode materials

[0221] In a pure oxygen atmosphere, the cathode material containing lithium precursor of Experiment 1.1 was sintered at 960℃ for 10 hours and then cooled naturally. 0.6 Co 0.1 Mn 0.3 O2 positive electrode material. The SEM image of the positive electrode material is shown in Figure 5, and the XRD spectrum is shown in Figure 6.

[0222] Experiment 1.3: Making a Lithium-ion Battery

[0223] The steps for preparing lithium-ion batteries include:

[0224] Positive electrode sheet preparation: Weigh the lithium-containing precursor from Experiment 1.1 or the positive electrode material from Experiment 1.2, along with the conductive agent (acetylene black), and binder (PVDF) in a weight ratio of 85%:10%:5%, and mix and grind. Then, add N-methylpyrrolidone (NMP) solvent to create a uniform positive electrode slurry. Use a spatula to evenly coat the slurry onto aluminum foil. Dry to obtain a positive electrode sheet ready for assembly into a battery.

[0225] Battery Assembly: In a glove box with a high-purity argon atmosphere, the prepared cathode sheet was assembled into a CR2025 button-type battery, creating a lithium-based counter-electrode button-type battery for subsequent electrochemical performance testing. The separator was a polyolefin porous membrane, and the electrolyte was ethylene carbonate.

[0226] In Experiment 1.1, the positive electrode material containing lithium precursor has a first discharge capacity of 68 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, while in Experiment 1.2, the positive electrode material has a first discharge capacity of 195.2 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, an initial coulombic efficiency of 90.5%, and a 50-cycle discharge capacity retention rate of 93.9%.

[0227] Example 2

[0228] Experiment 2.1: Preparation of Lithium-containing Precursors for Cathode Materials

[0229] A nitrate solution of nickel, cobalt, manganese, and lithium was prepared according to a molar ratio of Ni:Mn:Co:Li = 0.60:0.20:0.20:1.06, wherein the total concentration of nickel nitrate, cobalt nitrate, manganese nitrate, and lithium nitrate was 195 g / L;

[0230] The solution is introduced into a synthesis tower for spray pyrolysis, with powder discharged from the bottom. The powder is cooled in a cooler before being screened, pneumatically crushed, demagnetized, and packaged as finished products. Flue gas is drawn from the top by a fan, where it passes through a Venturi to scrub dust and cool the flue gas. The exhaust gas then passes through a heat exchanger to reduce its temperature to less than 30°C. The exhaust then undergoes multi-stage absorption to recover nitric acid, and finally undergoes alkaline washing and urea absorption to ensure that the exhaust meets emission standards.

[0231] Spray pyrolysis parameters: burner air-to-coal ratio (ratio of air and natural gas flow): 14:1;

[0232] Atomization parameters: Compressed air pressure: 0.3MPA

[0233] Compressed air and liquid flow volume ratio: 175:1

[0234] The temperature of the spray pyrolysis was 780° C., and the calcination treatment time was 10 seconds.

[0235] The chemical formula of the lithium-containing precursor is Li 1.06 (Ni 0.60 Co 0.20 Mn 0.20 )O 2.06 The positive electrode material lithium-containing precursor includes a plurality of flaky agglomerates formed by agglomeration of primary particles, the primary particles are 128 nm, the maximum thickness of the agglomerates is 6 μm, the maximum length is 16 μm, the maximum width is 14 μm, and the peak intensity of the peak at 18.7 ± 0.3 degrees 2θ in the powder X-ray diffraction pattern using Cu-Kα radiation is I a The peak intensity of the peak at 44.1±0.3 degrees 2θ is I b , I a with I b The peak intensity ratio is 0.5. The lithium-containing precursor has a layered structure. The tap density of the lithium-containing precursor is 1.63 g / cm 3 , bulk density is 0.55g / cm 3 The ratio of the tap density to the bulk density is 3, the D90 / D10 value of the lithium-containing precursor obtained from the particle size distribution measurement value is 8, the D50 of the lithium-containing precursor obtained from the particle size distribution measurement value is 3.1 μm, and the BET specific surface area is 10.5 m 2 The magnesium ion content is 350 ppm, the calcium ion content is 380 ppm, and the sulfate content in the lithium-containing precursor is 45 ppm.

[0236] Experiment 2.2: Preparation of positive electrode materials

[0237] In pure oxygen atmosphere, the cathode material containing lithium precursor of experiment 2.1 was sintered at 960℃ for 10 hours and then cooled naturally. 0.6 Co 0.2 Mn 0.2 O2 positive electrode material.

[0238] Experiment 2.3: Preparation of Lithium-ion Batteries

[0239] The steps for preparing lithium-ion batteries include:

[0240] Positive electrode sheet preparation: Weigh the lithium-containing precursor from Experiment 2.1 or the positive electrode material from Experiment 2.2, along with the conductive agent (acetylene black), and binder (PVDF) in a weight ratio of 85%:10%:5%, then mix and grind. Then, add N-methylpyrrolidone (NMP) solvent to create a uniform positive electrode slurry. Use a spatula to evenly coat the slurry onto aluminum foil. Dry to obtain a positive electrode sheet ready for assembly into a battery.

[0241] Battery Assembly: In a glove box with a high-purity argon atmosphere, the prepared cathode sheet was assembled into a CR2025 button-type battery, creating a lithium-based counter-electrode button-type battery for subsequent electrochemical performance testing. The separator was a polyolefin porous membrane, and the electrolyte was ethylene carbonate.

[0242] In Experiment 2.1, the positive electrode material containing lithium precursor has a first discharge capacity of 63mAh / g at a charge and discharge voltage of 3.0 to 4.4V, a temperature of 25°C, and 0.1C, while in Experiment 2.2, the positive electrode material has a first discharge capacity of 195.4mAh / g at a charge and discharge voltage of 3.0 to 4.4V, a temperature of 25°C, and 0.1C, an initial coulombic efficiency of 90.3%, and a 50-cycle discharge capacity retention rate of 94.8%.

[0243] Example 3

[0244] Experiment 3.1: Preparation of Lithium-containing Precursors for Cathode Materials

[0245] The experiment of Example 3 was conducted similarly to Example 1. Nitrate solutions of nickel, cobalt, manganese, and lithium were prepared according to a molar ratio of Ni:Mn:Co:Li=0.62:0.08:0.30:1.05, wherein the total concentration of nickel nitrate, cobalt nitrate, manganese nitrate, and lithium nitrate was 189 g / L.

[0246] The chemical formula for preparing the lithium-containing precursor is Li 1.05 (Ni 0.62 Co 0.08 Mn 0.30 )O 2.05The lithium-containing precursor of the positive electrode material includes a plurality of flaky agglomerates formed by agglomeration of primary particles, the primary particles are 144 nm, the maximum thickness of the agglomerates is 4.5 μm, the maximum length is 13 μm, the maximum width is 11 μm, and the peak intensity of the peak at 18.7 ± 0.3 degrees 2θ in the powder X-ray diffraction pattern using Cu-Kα radiation is I a The peak intensity of the peak at 44.1±0.3 degrees 2θ is I b , I a with I b The peak intensity ratio is 0.45. The lithium-containing precursor has a layered structure. The tap density of the lithium-containing precursor is 1.68g / cm 3 , the bulk density is 0.49g / cm 3 The ratio of tap density to bulk density is 3.5, the D90 / D10 value of the lithium-containing precursor obtained from the particle size distribution measurement value is 7.7, the D50 of the lithium-containing precursor obtained from the particle size distribution measurement value is 3.7 μm, and the BET specific surface area is 8.9 m 2 The magnesium ion content is 390 ppm, the calcium ion content is 430 ppm, and the sulfate content in the lithium-containing precursor is 35 ppm.

[0247] Experiment 3.2: Preparation of positive electrode materials

[0248] In a pure oxygen atmosphere, the cathode material containing lithium precursor of Experiment 3.1 was sintered at 965℃ for 10 hours and then cooled naturally. 0.6 Co 0.2 Mn 0.2 O2 positive electrode material.

[0249] Experiment 3.3: Preparation of Lithium-ion Batteries

[0250] A lithium-ion battery was prepared in the manner of Examples 1 and 2. The difference from Examples 1 and 2 was that the lithium-containing precursor in Experiment 3.1 and the positive electrode material in Experiment 3.2 were used as part of the lithium-ion battery.

[0251] The positive electrode material containing lithium precursor in Experiment 3.1 has a first discharge capacity of 59 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, while the positive electrode material in Experiment 3.2 has a first discharge capacity of 195.9 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, an initial coulombic efficiency of 90.7%, and a 50-cycle discharge capacity retention rate of 94.9%.

[0252] Example 4

[0253] Experiment 4.1: Preparation of Lithium-containing Precursors for Cathode Materials

[0254] A nitrate solution of nickel, cobalt, manganese, and lithium was prepared according to a molar ratio of Ni:Mn:Co:Li = 0.60:0.10:0.30:0.50, wherein the total concentration of nickel nitrate, cobalt nitrate, manganese nitrate, and lithium nitrate was 146 g / L;

[0255] The solution is introduced into a synthesis tower for spray pyrolysis, with powder discharged from the bottom. The powder is cooled in a cooler before being screened, pneumatically crushed, demagnetized, and packaged as finished products. Flue gas is drawn from the top by a fan, where it passes through a Venturi to scrub dust and cool the flue gas. The exhaust gas then passes through a heat exchanger to reduce its temperature to less than 30°C. The exhaust then undergoes multi-stage absorption to recover nitric acid, and finally undergoes alkaline washing and urea absorption to ensure that the exhaust meets emission standards.

[0256] Spray pyrolysis parameters: burner air-to-coal ratio (ratio of air and natural gas flow): 14:1;

[0257] Atomization parameters: compressed air pressure: 0.3MPA;

[0258] Compressed air and liquid flow volume ratio: 175:1;

[0259] The temperature of the spray pyrolysis was 630° C., and the calcination treatment time was 10 seconds.

[0260] The chemical formula of the lithium-containing precursor is Li 0.50 (Ni 0.60 Co 0.10 Mn 0.30 )O 1.50 The positive electrode material lithium-containing precursor includes a plurality of flaky agglomerates formed by agglomeration of primary particles, the primary particles are 138 nm, the maximum thickness of the agglomerates is 6 μm, the maximum length is 14 μm, the maximum width is 11 μm, and the peak intensity of the peak at 18.7 ± 0.3 degrees 2θ in the powder X-ray diffraction pattern using Cu-Kα radiation is I a The peak intensity of the peak at 44.1 ± 0.3 degrees 2θ is I b , I a with I b The peak intensity ratio is 0.4. The lithium-containing precursor has a layered structure. The tap density of the lithium-containing precursor is 1.49 g / cm 3 , the bulk density is 0.53g / cm 3 The ratio of tap density to bulk density is 2.8, the D90 / D10 value of the lithium-containing precursor obtained from the particle size distribution measurement value is 7.5, the D50 of the lithium-containing precursor obtained from the particle size distribution measurement value is 3.5 μm, and the BET specific surface area is 7.6 m 2 The magnesium ion content is 360 ppm, the calcium ion content is 430 ppm, and the sulfate content in the lithium-containing precursor is 41 ppm.

[0261] Experiment 4.2: Preparation of positive electrode materials

[0262] The positive electrode material containing lithium precursor and lithium carbonate of Experiment 4.1 were mixed and sintered at 970℃ for 10 hours in pure oxygen atmosphere, and then cooled naturally. 0.6 Co 0.1 Mn 0.3 O2 positive electrode material.

[0263] Experiment 4.3: Preparation of Lithium-ion Batteries

[0264] The steps for preparing lithium-ion batteries include:

[0265] Positive electrode sheet preparation: Weigh the lithium-containing precursor from Experiment 4.1 or the positive electrode material from Experiment 4.2, with a weight ratio of 85%:10%:5% for the conductive agent (acetylene black): binder (PVDF), and grind. Then, add N-methylpyrrolidone (NMP) solvent to create a uniform positive electrode slurry. Use a spatula to evenly coat the slurry onto aluminum foil. Dry to obtain a positive electrode sheet ready for assembly into a battery.

[0266] Battery Assembly: In a glove box with a high-purity argon atmosphere, the prepared cathode sheet was assembled into a CR2025 button-type battery, creating a lithium-based counter-electrode button-type battery for subsequent electrochemical performance testing. The separator was a polyolefin porous membrane, and the electrolyte was ethylene carbonate.

[0267] In Experiment 4.1, the positive electrode material containing lithium precursor has a first discharge capacity of 41 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, while in Experiment 4.2, the positive electrode material has a first discharge capacity of 194.8 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and 0.1C, an initial coulombic efficiency of 90.5%, and a 50-cycle discharge capacity retention rate of 94.5%.

[0268] Comparative Example 1

[0269] Experiment 5.1: Preparation of cathode material precursor

[0270] A positive electrode material precursor, the preparation of which comprises the following steps:

[0271] According to Ni 0.60 Co 0.10 Mn 0.30 The stoichiometric ratio of the metal elements in the (OH)2 chemical formula is obtained by mixing nickel chloride solution, cobalt chloride solution, and manganese chloride solution; then adding ammonia water and NaOH solution according to the ratio of ammonia to nickel: 0.5:1, and the ratio of alkali to nickel: 2:1, adding ammonia water and sodium hydroxide, controlling the reaction temperature at 55 ° C and the pH value at 12.0, and separating Ni after the reaction. 0.60 Co0.10 Mn 0.30 (OH)2 precursor.

[0272] Ni 0.60 Co 0.10 Mn 0.30 The (OH)2 precursor is spherical or quasi-spherical, Ni 0.60 Co 0.10 Mn 0.30 The tap density of (OH)2 precursor is 1.83g / cm3, Ni 0.60 Co 0.10 Mn 0.30 The D50 of the (OH)2 precursor obtained from the particle size distribution measurement value is 15 μm, and the BET specific surface area is 15 m 2 / g.

[0273] Experiment 5.2: Preparation of positive electrode materials

[0274] From Experiment 5.1, Ni 0.60 Co 0.10 Mn 0.30 (OH)2 precursor is mixed with lithium carbonate solid, Ni 0.60 Co 0.10 Mn 0.30 After the (OH)2 precursor is mixed with lithium carbonate solid, it is sintered at least twice to obtain LiNi 0.6 Co 0.1 Mn 0.3 O2 positive electrode material. The difference from Examples 1, 2, 3, and 4 is that the Ni 0.60 Co 0.10 Mn 0.30 The (OH)2 precursor must be mixed with a lithium source to form a positive electrode material. Secondly, when the lithium-containing precursors of Examples 1, 2, 3, and 4 are sintered into positive electrode materials, only one sintering is required to form the positive electrode material, while the Ni 0.60 Co 0.10 Mn 0.30 When the (OH)2 precursor is sintered into a positive electrode material, it must be sintered more than twice to form the positive electrode material.

[0275] Experiment 5.3: Preparation of Lithium-ion Batteries

[0276] The steps for preparing lithium-ion batteries include:

[0277] Positive electrode preparation: According to the Ni 0.60 Co 0.10 Mn 0.30Weigh the (OH)2 precursor or the positive electrode material from Experiment 5.2: conductive agent (acetylene black): binder (PVDF) in a weight ratio of 85%:10%:5%, then mix and grind. Then, add N-methylpyrrolidone (NMP) solvent to create a uniform positive electrode slurry. Use a spatula to evenly coat the slurry onto aluminum foil. Dry to obtain a positive electrode sheet that can be directly assembled into a battery.

[0278] Battery Assembly: In a glove box with a high-purity argon atmosphere, the prepared cathode sheet was assembled into a CR2025 button-type battery, creating a lithium-based counter-electrode button-type battery for subsequent electrochemical performance testing. The separator was a polyolefin porous membrane, and the electrolyte was ethylene carbonate.

[0279] In experiment 5.2, the positive electrode material had a first discharge capacity of 194.5 mAh / g at a charge and discharge voltage of 3.0 to 4.4 V, a temperature of 25°C, and a 0.1C charge and discharge rate. The first coulombic efficiency was 90.1%, and the 50-cycle discharge capacity retention rate was 94.2%.

[0280] By comparing Examples 1, 2, 3, and 4 with the comparative examples, it can be seen that the lithium-containing precursor of the positive electrode material disclosed in the present application is an oxide lithium-containing precursor. When the lithium-containing precursor is sintered into a positive electrode material, no wastewater is generated due to the absence of hydroxide. The lithium-containing precursor exists in the form of an oxide. Compared with the traditional hydroxide precursor, the oxide precursor has a higher content of main metals of nickel, cobalt, and manganese. At the same time, the precursor also contains lithium. When sintered into a positive electrode material, the loss rate of lithium during sintering of the positive electrode material is reduced, and the yield of the finished product under the same loading amount is increased, thereby increasing the output when sintering into the positive electrode material, reducing the manufacturing cost of the positive electrode material, and greatly increasing the production line capacity. The lithium-containing precursor in this application is formed by atomization roasting. Compared with the hydroxide precursor prepared by the coprecipitation method, the process of this application is simple, with few intermediate processes, and the reaction process is easy to flexibly control. The roasting process is carried out while atomizing, which not only ensures that the product has a smaller particle size, but also the product reaction speed is fast. The actual reaction time of obtaining the lithium-containing precursor material by atomization roasting is only a few seconds, and the production efficiency is high. In addition, since the anions in the salt solution are converted into gaseous substances in a high temperature environment and removed or recycled, the raw material utilization rate is high, the impurity content in the product is low, and the performance is excellent. At the same time, the lithium-containing precursor material product prepared by this method has a better structural stability of the material itself than the traditional coprecipitation method. When the hydroxide precursor prepares the positive electrode material, the positive electrode hydroxide precursor usually needs to be mixed with a lithium source for solid mixing and then sintered at high temperature. However, due to the uneven mixing between the solids and the slow diffusion rate of lithium in the solid phase, it may be difficult to make the lithium uniformly distributed, and the uneven distribution of lithium will seriously affect the electrochemical properties of the positive electrode material. When the lithium-containing precursor of the present application is used to prepare the positive electrode material, since the lithium-containing precursor itself has lithium, when preparing the positive electrode material, only a small amount of lithium source needs to be added or no lithium source needs to be added to directly sinter it into the positive electrode material, making the distribution of lithium more uniform and improving the electrochemical performance of the positive electrode material. On the other hand, by directly pre-burning lithium into the precursor, the subsequent mixing process of the precursor and the lithium source is reduced, simplifying the production process of the positive electrode material; compared with the traditional precursor and lithium carbonate sintering process, the decomposition of lithium carbonate into carbon dioxide is reduced, reducing carbon emissions; since lithium is directly pre-burned into the precursor, the temperature of the lithium-containing precursor of the present application when sintering the positive electrode material is lower than the temperature of the traditional precursor sintering the positive electrode material under the same conditions, thus reducing the sintering cost. On the other hand, since the suppliers of positive electrode material precursors and lithium source suppliers are usually independent of each other, it is difficult for downstream positive electrode material manufacturers to strictly control the product quality and batch stability of positive electrode material precursor suppliers and lithium source suppliers, which is not conducive to the stability of positive electrode material preparation. The lithium-containing precursor of this application itself contains lithium, therefore, it solves the raw material supply problem of positive electrode material manufacturers to a certain extent and improves the stability of positive electrode material preparation.

[0281] While the present invention is illustrated by the above-described embodiments, the present invention is not limited to the above-described process steps, and implementation of the present invention is not necessarily dependent on the above-described process steps. Those skilled in the art will appreciate that any improvements to the present invention, equivalent substitutions for the raw materials used, additions of auxiliary components, and selection of specific methods, etc., fall within the scope of protection and disclosure of the present invention.

[0282] In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments. The scope of protection of the present invention is not limited to the above-mentioned embodiments, and the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A positive electrode material containing a lithium precursor, wherein: The positive electrode material contains a lithium precursor satisfying the chemical formula: Li a (Ni x Co y Mn 1-x-y ) (1+a) , wherein a, x, y are expressed in mol, 0.10≤a≤1.1, 0<x<1, 0<y<1 and x+y<1.

2. The positive electrode material containing lithium precursor according to claim 1, wherein The chemical formula Li a (Ni x Co y Mn 1-x-y ) (1+a) , 0.50≤x≤0.90, 0.01≤y≤0.

40.

3. The positive electrode material containing lithium precursor according to claim 2, wherein The chemical formula Li a (Ni x Co y Mn 1-x-y ) (1+a) , 0.55≤x≤0.80, 0.01≤y≤0.

09.

4. The positive electrode material containing lithium precursor according to claim 1, wherein The chemical formula Li a (Ni x Co y Mn 1-x-y ) (1+a ), the value range of a is 0.10≤a≤0.50 or 1<a≤1.

08.

5. The positive electrode material containing lithium precursor according to claim 1, wherein The positive electrode material lithium-containing precursor includes at least one sheet-like agglomerate formed by agglomeration of primary particles.

6. The positive electrode material containing lithium precursor according to claim 5, wherein: The maximum thickness of the flake aggregate is 0.1 to 10 μm, the maximum length of the flake aggregate is 0.1 to 30 μm, and the maximum width of the flake aggregate is 0.1 to 30 μm.

7. The positive electrode material containing lithium precursor according to claim 5, wherein: The positive electrode material lithium-containing precursor comprises at least two sheet-like aggregates, and there are gaps between the sheet-like aggregates, and the gaps are in the range of 1 nm to 1 μm.

8. The lithium-containing precursor of the positive electrode material according to claim 5, wherein: The particle size of the primary particles is 100 to 200 nanometers.

9. The positive electrode material containing lithium precursor according to claim 1, wherein In the powder X-ray diffraction pattern by using Cu-Kα rays, there are diffraction peaks at 18.7±0.3, 36.5±0.3, 37.9±0.3, 44.1±0.3, 48.4±0.3, 58.3±0.3, 64.2±0.3, 67.9±0.3 degrees 2θ; and / or in a powder x-ray diffraction pattern using Cu-Kα radiation, a ratio of a half-peak width α of a peak at 18.7±0.3 degrees 2θ to a half-peak width β of a peak at 44.1±0.3 degrees 2θ is 0.8 to 1.8, the half-peak width α is in the range of 0.50 to 0.70 degrees, and the half-peak width β is in the range of 0.30 to 0.50 degrees; and / or in the powder x-ray diffraction pattern using Cu-Kα radiation, the peak intensity of the peak at 18.7±0.3 degrees 2θ is I a , the peak intensity of the peak at 44.1±0.3 degrees 2θ is I b , I a with I b The peak intensity ratio is greater than 0.2 Less than 1.

10. The positive electrode material containing lithium precursor according to claim 1, wherein: The tap density of the lithium-containing precursor of the positive electrode material is 0.8 to 2.5 g / cm 3 The bulk density is 0.4 to 0.9 g / cm 3 .

11. The lithium-containing precursor of the positive electrode material according to claim 1, wherein: The positive electrode material lithium-containing precursor has a D90 of 5 to 40 μm, a D50 of 1.0 to 15 μm, and a D10 of 0.5 to 8 μm, as determined by particle size distribution measurement.

12. The positive electrode material containing lithium precursor according to claim 1, wherein The ratio of the BET specific surface area of ​​the lithium-containing precursor of the positive electrode material to D50 is 3×10 6 ~15×10 6 m / g.

13. The lithium-containing precursor of the positive electrode material according to claim 12, wherein: The BET specific surface area is 2 to 20 m 2 / g.

14. The positive electrode material containing lithium precursor according to claim 1, wherein: The calcium ion content in the lithium-containing precursor of the positive electrode material is less than 500 ppm; and / or the content of magnesium ions in the lithium-containing precursor of the positive electrode material is less than 500 ppm; and / or the sulfate content in the lithium-containing precursor of the positive electrode material is less than 50 ppm; and / or the sodium ion content in the lithium-containing precursor of the positive electrode material is below 50 ppm; And / or the contents of hydrochloride, phosphate and oxalate in the lithium-containing precursor of the positive electrode material are each below 100 ppm.

15. The lithium-containing precursor of the positive electrode material according to claim 1, wherein: The crystal structure of the lithium-containing precursor of the positive electrode material is a layered structure.

16. The lithium-containing precursor of the positive electrode material according to claim 15, wherein: The crystal form of the lithium-containing precursor of the positive electrode material is one or more of spinel, cubic and octahedral types.

17. The positive electrode material containing lithium precursor according to claim 1, wherein: The positive electrode material contains a lithium precursor with a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge capacity of less than 150 mAh / g.

18. The positive electrode material containing lithium precursor according to claim 17, wherein: The positive electrode material contains a lithium precursor with a charge and discharge voltage of 3.0 to 4.4 V and a 0.1C first discharge capacity of 10 to 70 mAh / g.

19. A method for preparing a lithium-containing precursor of a positive electrode material, comprising the following steps: preparing a mixed solution of lithium nitrate, nickel nitrate, cobalt nitrate and manganese nitrate; The mixed solution is subjected to atomization and calcination treatment to obtain a positive electrode material containing lithium precursor, the atomization The temperature of the calcination treatment is 300°C-1000°C, and the positive electrode material contains a lithium precursor that satisfies the chemical formula: Li a (Ni x Co y Mn 1-x-y ) (1+a) ,in, a, x, y are expressed in mol, 0.10≤a≤1.1, 0<x<1, 0<y<1 and x+y<1.

20. A positive electrode material, wherein: The positive electrode material is formed by sintering a positive electrode material containing lithium precursor, and the positive electrode material containing lithium precursor satisfies the chemical formula: Li a (Ni x Co y Mn 1-x-y ) (1+a) , wherein a, x, y are expressed in mol, 0.10≤a≤1.1, 0<x<1, 0<y<1 and x+y<1.

Images