WO2021073583A1 - 锂电池正极材料前驱体、其制备方法及应用 - Google Patents

锂电池正极材料前驱体、其制备方法及应用 Download PDF

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WO2021073583A1
WO2021073583A1 PCT/CN2020/121341 CN2020121341W WO2021073583A1 WO 2021073583 A1 WO2021073583 A1 WO 2021073583A1 CN 2020121341 W CN2020121341 W CN 2020121341W WO 2021073583 A1 WO2021073583 A1 WO 2021073583A1
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Prior art keywords
positive electrode
precursor
electrode material
cathode material
lithium battery
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PCT/CN2020/121341
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English (en)
French (fr)
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张同宝
汪碧微
朱烨
高焕新
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中国石油化工股份有限公司
中国石油化工股份有限公司上海石油化工研究院
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Priority claimed from CN201910990467.8A external-priority patent/CN112687870B/zh
Priority claimed from CN201910989951.9A external-priority patent/CN112687871B/zh
Priority to BR112022006646A priority Critical patent/BR112022006646A2/pt
Priority to KR1020227016598A priority patent/KR20220084363A/ko
Priority to CA3156276A priority patent/CA3156276A1/en
Priority to EP20877356.4A priority patent/EP4047690A4/en
Application filed by 中国石油化工股份有限公司, 中国石油化工股份有限公司上海石油化工研究院 filed Critical 中国石油化工股份有限公司
Priority to MX2022004587A priority patent/MX2022004587A/es
Priority to US17/754,967 priority patent/US20220388863A1/en
Priority to AU2020367186A priority patent/AU2020367186A1/en
Priority to JP2022522945A priority patent/JP2022553217A/ja
Publication of WO2021073583A1 publication Critical patent/WO2021073583A1/zh
Priority to ZA2022/05597A priority patent/ZA202205597B/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/006—Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/74—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by peak-intensities or a ratio thereof only
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/04—Particle morphology depicted by an image obtained by TEM, STEM, STM or AFM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/40—Electric properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/028—Positive electrodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • This application relates to the field of lithium batteries, in particular to a lithium battery cathode material precursor, its preparation method and application.
  • Lithium-ion batteries also referred to as “lithium batteries” in this application
  • Lithium batteries have the advantages of high energy density, high output voltage, low self-discharge, excellent cycle performance, and no memory effect. They are widely used in portable electronic products, power tools and electric vehicles And other fields. Especially in recent years, the new energy vehicle promotion policies issued by governments of various countries have been continuously upgraded, which has given birth to the explosive development of power lithium batteries.
  • the cathode material is the key core component of the lithium battery. It not only determines the key core indicators such as the energy density of the lithium battery, but also accounts for about 40% of the cost of the entire battery. With the continuous improvement of people's requirements for the cruising range of electric vehicles, ternary cathode materials with higher energy density have gradually become the mainstream cathode materials for passenger cars.
  • the morphology of lithium battery cathode material has an important influence on its electrochemical performance.
  • One kind of morphology is secondary micron polycrystalline spherical aggregate particles formed by agglomeration of nanometer or submicron primary particles.
  • the fine polycrystalline particles of the cathode material with this morphology can fully contact the electrolyte, and the rate performance It is better, but the fine polycrystalline particles are prone to side reactions with the electrolyte, resulting in the dissolution of transition metals in the electrolyte, and the cycle stability of the battery is poor.
  • the other morphology is dispersed single crystal particles.
  • the positive electrode material with this morphology has a stable crystal structure, has good compatibility with the electrolyte during charge and discharge, and is not easily broken during the cycle, and the battery cycle is stable The performance is good, but due to the larger size of the dispersed single crystal particles, the capacity and rate performance are poor.
  • ternary cathode material its morphology is basically determined by its precursor.
  • the morphology of the current commercial ternary cathode material precursors is mainly secondary micron polycrystalline spherical aggregate particles formed by agglomeration of nano- or sub-micron primary particles.
  • Chinese Patent Application Publication CN107915263A discloses a precursor material with the morphology of secondary micron polycrystalline spherical aggregates with a size of 3.5-4.0 ⁇ m. During the charging and discharging process of this kind of materials, the small primary particles will contact and react with the electrolyte, resulting in low capacity and first week efficiency of polycrystalline materials, which is difficult to meet the practical application requirements in power batteries.
  • an object of the present application is to provide a new type of lithium battery cathode material precursor, its preparation method and application.
  • the lithium battery cathode material prepared by using the precursor has improved electrical properties. Chemical properties.
  • the present application provides a lithium battery cathode material precursor, the precursor has the chemical formula Ni x Co y M z (OH) 2 , and M is selected from Fe, Cr, Cu, Ti, At least one metal of Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn, and Al, where 0.3 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.3, and x, y
  • the values of and z satisfy the rule of electrical neutrality
  • the precursor includes sheet-like single crystal agglomerates and polyhedral single crystal particles, and in the XRD pattern of the precursor, I(001), I(100) and I(101) satisfy the following relationship:
  • I(001)/I(100) is not less than about 1.5
  • I(001)/I(101) is not less than about 1.2
  • I(101)/I(100) is not less than about 1.3,
  • I(001), I(100) and I(101) represent the diffraction peak intensity of (001) crystal plane, (100) crystal plane and (101) crystal plane in terms of diffraction peak height, respectively.
  • this application provides a method for preparing a lithium battery cathode material precursor, which includes the following steps:
  • step (2) subjecting the product obtained in step (1) to solid-liquid separation and drying treatment to obtain the precursor;
  • the metal in the metal salt solution includes Ni, Co, and M
  • the metal M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn, and Al.
  • the molar amount ratio of Ni, Co and M is about (0.3-1):(0-0.5):(0-0.3), wherein the molar amount of Co and M is not zero.
  • the present application provides a lithium battery cathode material precursor prepared by the method for preparing a lithium battery cathode material precursor of the present application.
  • the present application provides a lithium battery cathode material
  • the cathode material has the chemical formula Li a Ni x Co y M z O 2
  • M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, At least one metal of Nb, Zn, Sn, Zr, Ga, Mn, and Al, wherein 0.9 ⁇ a ⁇ 1.2, 0.3 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.3, and a, x
  • the values of, y and z satisfy the electric neutrality rule;
  • the positive electrode material comprises particles in the form of secondary single crystal fusions formed by at least partial fusion of primary single crystal particles.
  • this application provides a method for preparing a lithium battery cathode material, which includes the following steps:
  • the precursor is a lithium battery cathode material precursor according to the present application.
  • the present application provides a lithium battery cathode material prepared by the method for preparing a lithium battery cathode material of the present application.
  • the present application provides a lithium battery positive electrode, comprising a positive electrode material, a binder, and a conductive agent, wherein the positive electrode material is the lithium battery positive electrode material according to the present application.
  • the present application provides a lithium battery including a positive electrode, a negative electrode, an electrolyte, and a separator, wherein the positive electrode is a lithium battery positive electrode according to the present application.
  • the lithium battery cathode material precursor of the present application is different from the ternary cathode material precursor with the morphology of polycrystalline spherical aggregates, and includes sheet-like single crystal aggregates and polyhedral single crystal particles, and its (001) crystal plane and (101) The exposed area of the crystal plane is more, so as to endow the positive electrode material precursor with better electrochemical performance.
  • the lithium battery cathode material of the present application is different from the existing cathode materials in the form of polycrystalline spherical agglomerates and dispersed single crystal particles, and includes particles in the form of secondary single crystal fusions formed by at least partial fusion of primary single crystal particles.
  • the positive electrode material combines the advantages of polycrystalline spherical agglomerates and dispersed single crystal ternary positive electrode materials, and has the characteristics of high discharge capacity, high first week efficiency, good rate performance and good cycle stability.
  • the lithium battery using this cathode material has a discharge capacity of 206.9mAh/g at a rate of 0.1C, and an efficiency of 92.1% in the first week; at a rate of 1C, the capacity retention rate can reach 96.1% after 80 cycles; Under 10C rate, the discharge capacity can reach 120mAh/g.
  • FIG. 1A is an SEM image of the cathode material precursor prepared in Example 1 of the present application.
  • FIG. 1B is an SEM image of the positive electrode material precursor prepared in Example 1 of the present application.
  • Example 2 is an XRD pattern of the precursor of the positive electrode material prepared in Example 1 of the present application;
  • 3A is an SEM image of the cathode material prepared in Example 1 of the present application.
  • 3B is an SEM image of the positive electrode material prepared in Example 1 of the present application.
  • 3C is a TEM image of the cathode material prepared in Example 1 of the present application.
  • 3D is an SEM image of a cross-section of the cathode material prepared in Example 1 of the present application;
  • Example 4 is an XRD pattern of the cathode material prepared in Example 1 of the present application.
  • Example 5 is a charge-discharge curve of a lithium battery assembled from the positive electrode material of Example 1 of the present application at a rate of 0.1C;
  • Example 6 is a cycle capacity retention curve of a lithium battery assembled from the positive electrode material of Example 1 of the present application at a rate of 0.1C;
  • FIG. 7 is the capacity results of the lithium battery assembled from the positive electrode material of Example 1 of the present application under different magnifications
  • FIG. 8 is an SEM image of the cathode material precursor prepared in Comparative Example 1 of the present application.
  • FIG. 9 is an XRD pattern of the cathode material precursor prepared in Comparative Example 1 of the present application.
  • FIG. 10A is an SEM image of the positive electrode material prepared in Comparative Example 1 of the present application.
  • FIG. 11 is the capacity results of the lithium battery assembled from the positive electrode material of Comparative Example 1 of the present application under different magnifications;
  • a flake-shaped single crystal agglomerates and B polyhedral single crystal particles are provided.
  • any specific numerical value (including the end point of the numerical range) disclosed in this document is not limited to the precise value of the numerical value, but should be understood to also encompass values close to the precise value.
  • between the endpoints of the range, between the endpoints and the specific point values in the range, and between the specific point values can be arbitrarily combined to obtain one or more new Numerical ranges, these new numerical ranges should also be regarded as specifically disclosed herein.
  • the term "agglomerate” refers to an aggregate formed by a plurality of particles gathered together through physical interaction (such as electrostatic force and van der Waals force, etc.). The interaction force between the particles is weak, so it is easy to act on external forces. The next disintegration.
  • fusion refers to a whole structure formed by a plurality of particles at least partially fused together, in which the individual particles have been fused with each other into one body, and thus are not easily damaged by external forces.
  • the expression "at least partially fused” means that at least a part of the particle shape is fused with at least a part of other particles to form a whole.
  • the “feeding in a batch mode” means that the metal salt solution is fed into the reaction system intermittently in multiple times (for example, 2, 3, 4, 5, 6 times, etc.), preferably each time
  • the feeding is carried out in a continuous manner, especially in a continuous manner at a constant speed, until a predetermined time or a predetermined amount of material has been added.
  • any matters or matters not mentioned are directly applicable to those known in the art without any changes.
  • any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or technical ideas formed thereby shall be regarded as part of the original disclosure or original record of the present invention, and shall not be It is regarded as new content that has not been disclosed or anticipated in this article, unless those skilled in the art think that the combination is obviously unreasonable.
  • the present application provides a lithium battery cathode material precursor, the precursor comprising sheet-like single crystal agglomerates and polyhedral single crystal particles, and the XRD pattern of the precursor, I (001), The following relationship is satisfied between I(100) and I(101):
  • I(001)/I(100) is not less than about 1.5, preferably not more than about 10, and
  • I(001)/I(101) is not less than about 1.2, preferably not more than about 5,
  • I(101)/I(100) is not lower than about 1.3, preferably not higher than about 5;
  • the precursor has the chemical formula Ni x Co y M z (OH) 2 , and M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn and Al At least one metal, where 0.3 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.3, and the values of x, y, and z satisfy the rule of electrical neutrality.
  • the precursor includes flaky single crystal agglomerates and polyhedral single crystal particles.
  • the precursor basically consists of flaky single crystal agglomerates and polyhedral single crystal particles.
  • the "sheet-like single crystal agglomerate” refers to a particle with a primary morphology of a sheet-like single crystal, and a secondary morphology of the above-mentioned sheet-like single crystal agglomeration.
  • the "polyhedral single crystal” “Particle” refers to a single crystal particle with a polyhedral morphology.
  • the I(001) refers to the diffraction peak intensity of the (001) crystal plane
  • the I(100) refers to the diffraction peak intensity of the (100) crystal plane
  • the I(101) refers to the (101) ) The diffraction peak intensity of the crystal plane, wherein the diffraction peak intensity is based on the height of the diffraction peak.
  • I(001), I(100) and I(101) satisfy the following relationship: I(001)/I(100) is not low It is not higher than about 1.5 and not higher than about 10, such as not higher than about 5 or not higher than about 3; I(001)/I(101) is not lower than about 1.2 and not higher than about 5, such as not higher than about 3 Or not higher than about 2, and I(101)/I(100) is not lower than about 1.3 and not higher than about 5, such as not higher than about 3 or not higher than about 2.
  • I(001), I(100) and I(101) satisfy the following relationship: I(001)/I(100) is not low At about 1.8, I(001)/I(101) is not less than about 1.3, and I(101)/I(100) is not less than about 1.5.
  • I(001), I(100) and I(101) satisfy the following relationship: I(001)/I(100) is not less than About 1.8 and not higher than about 10, such as not higher than about 5 or not higher than about 3; I(001)/I(101) is not lower than about 1.3 and not higher than about 5, such as not higher than about 3 or Not higher than about 2; and I(101)/I(100) is not lower than about 1.5 and not higher than about 5, such as not higher than about 3 or not higher than about 2.
  • M is at least one of Mn, Al and Mg, or at least one of Mn, Al and Mg and selected from Fe, Cr, Cu, Ti, W, Mo, Nb, Zn A combination of at least one of, Sn, Zr, and Ga.
  • the precursor may have the chemical formula Ni x Co y Mn z (OH) 2 , Ni x Co y Al z (OH) 2 or Ni x Co y Mg z (OH) 2 , where x, y and z are defined As mentioned earlier.
  • the SEM images of the precursor are shown in FIG. 1A and FIG. 1B.
  • the lithium battery cathode material precursor described in the present application includes sheet-like single crystal aggregates and polyhedral single crystal particles.
  • the positive electrode material precursor has at least three diffraction peaks, including the (001) diffraction peak at a 2 ⁇ angle of 19.6°, a (100) diffraction peak at a 2 ⁇ angle of 33.4°, and The (101) diffraction peak located near the 2 ⁇ angle of 38.8°.
  • the diffraction peaks of the precursor are sharp, indicating that the crystal structure is well developed, and the diffraction peaks of (001) and (101) crystal planes have high intensity, indicating that the precursors have (001) and (101) crystal planes, especially (001) The crystal face is more fully exposed.
  • the lithium battery cathode material precursor of the present application and the existing cathode material precursors with the morphology of polycrystalline spherical aggregates.
  • the morphology of the existing polycrystalline spherical aggregates is spherical or quasi-spherical, and diffraction
  • the intensity of the peak is also significantly lower than the precursor material described in this application.
  • the particle size (D50) of the positive electrode material precursor is preferably 2-12 ⁇ m, and the method for measuring the particle size is dynamic light scattering technology.
  • this application provides a method for preparing a precursor of a lithium battery cathode material, which includes the following steps:
  • step (2) subjecting the product obtained in step (1) to solid-liquid separation and drying treatment to obtain the positive electrode material precursor;
  • the metal in the metal salt solution includes Ni, Co, and M
  • the metal M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn, and Al.
  • the molar amount ratio of Ni, Co and M is about (0.3-1):(0-0.5):(0-0.3), wherein the molar amount of Co and M is not zero.
  • the morphology of the precursor obtained by continuously feeding the raw materials is basically polycrystalline spherical agglomerates, and the morphology of the precursor is basically polycrystalline spherical agglomerates through intermittent feeding.
  • the precursor is prepared by the method of metal salt solution, a precursor containing sheet-like single crystal agglomerates and polyhedral single crystal particles can be obtained.
  • Such a precursor with a special morphology has better electrochemical performance.
  • the molar amount ratio of the metals Ni, Co and M in the metal salt solution is about (0.6-0.95):(0.025-0.2):(0.025-0.2).
  • the metal salt solution may be a metal salt solution conventionally used in the art for preparing lithium battery cathode materials or cathode material precursors.
  • the metal M is at least one of Mn, Al and Mg, or at least one of Mn, Al and Mg and selected from Fe, Cr, Cu, Ti, W, Mo, Nb, Zn, Sn, A combination of at least one of Zr and Ga.
  • the metal in the metal salt solution may be a combination of Ni, Co, and Mn, a combination of Ni, Co, and Al, or a combination of Ni, Co, and Mg.
  • the type of metal salt forming the metal salt solution is not particularly limited.
  • the metal salt is selected from at least one of sulfate, nitrate, acetate, chloride and oxalate.
  • the salt of metal Ni can be selected from at least one of nickel sulfate, nickel nitrate, nickel acetate, nickel oxalate and nickel chloride;
  • the salt of metal Co can be selected from cobalt nitrate, cobalt chloride, cobalt acetate and cobalt sulfate
  • the salt of metal Mn can be selected from at least one of manganese sulfate, manganese nitrate, manganese acetate and manganese chloride;
  • the salt of metal Al can be selected from aluminum nitrate, aluminum chloride, aluminum acetate and aluminum sulfate
  • the salt of metal Mg can be selected from at least one of magnesium nitrate, magnesium chloride, magnesium acetate and magnesium sulfate.
  • the concentration of the metal salt solution is about 0.01 to 5 mol/L, for example, it can be about 0.01 mol/L, about 0.1 mol/L, about 0.5 mol/L, or about 1 mol. /L, about 2mol/L, about 3mol/L, about 4mol/L, about 5mol/L, or within the range of any two of these values, more preferably about 0.5-3mol/L, and still more preferably About 1-2mol/L.
  • the type of the precipitation agent is not particularly limited.
  • the precipitation agent may be selected from at least one of NaOH, KOH and LiOH.
  • the concentration of the precipitation agent solution is not particularly limited.
  • the concentration of the precipitant solution may be about 0.02-10 mol/L, for example, about 0.02 mol/L, about 0.1 mol/L, about 0.5 mol/L, about 1 mol/L, about 2 mol/L, About 3mol/L, about 4mol/L, about 5mol/L, about 6mol/L, about 7mol/L, about 8mol/L, about 9mol/L, about 10mol/L, or any two of these values Within the numerical range, it is more preferably about 2-8 mol/L, and still more preferably about 2-6 mol/L.
  • the type of the complexing agent is not particularly limited, and it can be any compound that can form a complex with Ni, Co, and M in an aqueous solution.
  • the complexing agent is selected from at least one of ammonium ion donors, ethanolamine complexing agents, aminocarboxylic acid complexing agents, hydroxylaminocarboxylic acid complexing agents and carboxylate complexing agents .
  • the ammonium ion donor is preferably at least one selected from ammonia, ammonium oxalate, ammonium carbonate and ammonium hydroxide;
  • the ethanolamine complexing agent is preferably diethanolamine;
  • the aminocarboxylic acid complexing agent is preferably At least one selected from sodium triacetate (NTA), ethylenediaminetetraacetic acid and its salts (EDTA), and diethylenetriaminepentaacetic acid (DTPA);
  • the hydroxylaminocarboxylic acid complexing agent is preferably selected From ethylenediaminetetraacetic acid (HEDTA), ethylene glycol bis( ⁇ -diaminoethyl) ether-N,N,N'N'-tetraacetic acid (EGTA) and its salts, and dihydroxyglycine and its salts
  • the carboxylate complexing agent is preferably selected from oxalic acid and its salts, tartaric acid and its salts, citric acid and its salts,
  • the concentration of the complexing agent solution is not particularly limited.
  • the concentration of the complexing agent solution is about 0.01-15 mol/L, such as about 0.01 mol/L, about 0.1 mol/L, about 0.5 mol/L, about 1 mol/L, about 2 mol/L, About 3mol/L, about 4mol/L, about 5mol/L, about 6mol/L, about 7mol/L, about 8mol/L, about 9mol/L, about 10mol/L, about 11mol/L, about 12mol/L, About 13 mol/L, about 14 mol/L, about 15 mol/L, or within a range of any two of these values, more preferably about 2-10 mol/L, more preferably about 2-6 mol/L.
  • the reaction conditions in step (1) preferably include: the temperature is about 30-70°C, preferably about 45-60°C; the time is not less than about 10h, preferably about 24-72h; the pH is about 9- 14, preferably about 9-12, and the metal salt solution is fed into the reaction system at least twice.
  • the temperature is about 30-70°C, preferably about 45-60°C; the time is not less than about 10h, preferably about 24-72h; the pH is about 9- 14, preferably about 9-12, and the metal salt solution is fed into the reaction system at least twice.
  • the step (1) further includes:
  • each step (1a) does not exceed about 5/6 of the total time of step (1), preferably does not exceed about 2/3.
  • step (1) the pH of the reaction system is controlled in the range of about 9-14, preferably in the range of about 9-12.
  • the pH of the reaction system is controlled within the range of about 9-12, preferably within the range of about 10-11.5.
  • the amount of the metal salt, the precipitating agent and the complexing agent can be selected in a wide range, usually on a molar basis, the amount ratio of the metal salt, the precipitating agent and the complexing agent can be about 1: (1.5-3): (0.5-6).
  • the feed rate of each reaction material can be selected in a wide range, as long as the feed rate can meet the requirements to keep the pH value of the reaction system in step (1), especially step (1a) Within the range.
  • a matching reactor size can be selected based on the total amount of reaction materials, and then a suitable feed rate can be determined according to factors such as reactor size and reaction time. This is easily determined by those skilled in the art based on the disclosure of this application. of.
  • the ratio of the feed rate of the metal salt solution and the complexing agent solution can generally be about 0.5-6 by volume.
  • the feed rate of the precipitant is controlled to keep the pH value of the reaction system within a set range.
  • the feed rate of the metal salt solution is about 10-200 mL/h based on the total amount of 1L of the metal salt solution; the feed rate of the precipitant solution is based on the total amount of 1L of the precipitant solution.
  • the feed rate is about 10-200 mL/h; based on the total amount of 1 L of the complexing agent solution, the feed rate of the complexing agent solution is about 10-200 mL/h.
  • Those skilled in the art can control the feed rate according to the needs of pH.
  • the feed rate of the metal salt solution is about 10-200 mL/h, which means that the size of the reactor matches the total amount of reaction materials.
  • the feed rate of the metal salt solution is about 10-200 mL/h per 1 L of the metal salt solution.
  • the feed rate of the metal salt solution is about 5-100 mL/h; and when the total amount of the metal salt solution is 5L, the feed rate of the metal salt solution is about 50- 1000mL/h.
  • the feeding method of each reaction material is not particularly limited, and it can be carried out in a conventional method in the field, for example, it can be carried out in a dripping method.
  • the mixing in step (1) is carried out under stirring conditions. More preferably, the stirring speed is about 50-1000 r/min, for example, it can be about 50 r/min, about 80 r/min, or about 100 r/min. /min, about 200r/min, about 300r/min, about 400r/min, about 500r/min, about 600r/min, about 700r/min, about 800r/min, about 900r/min, about 1000r/min, or Within the numerical range formed by any two of these numerical values, it is more preferably about 600-1000 r/min.
  • the temperature of the product is preferably lowered to room temperature, for example, it may be about 25°C.
  • step (2) the solid-liquid separation described in step (2) can be performed in any suitable manner, as long as the prepared precursor can be separated, for example, filtration or centrifugation can be used.
  • the product obtained by the solid-liquid separation is washed.
  • the drying treatment described in step (2) can be carried out in any conventional manner in the art, for example, it can be vacuum drying, air drying, freeze drying or drying.
  • the conditions of the drying treatment can be selected in a wide range, for example, the temperature is about 70-150° C., and the time is about 4-16 h.
  • the present application provides a lithium battery cathode material precursor prepared by the foregoing method for preparing a lithium battery cathode material precursor.
  • the characteristics of the lithium battery cathode material precursor according to the third aspect of the present application are as described in the first aspect of the above text application, and the description will not be repeated here.
  • the present application provides a lithium battery cathode material, which comprises particles in the form of secondary single crystal fusions formed by at least partially fusion of primary single crystal particles;
  • the positive electrode material has the chemical formula Li a Ni x Co y M z O 2 , and M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn and Al At least one metal, where 0.9 ⁇ a ⁇ 1.2, 0.3 ⁇ x ⁇ 1, 0 ⁇ y ⁇ 0.5, 0 ⁇ z ⁇ 0.3, and the values of a, x, y, and z satisfy the rule of electrical neutrality.
  • the cathode material includes particles in the form of secondary single crystal fusions formed by at least partially fusion of primary single crystal particles.
  • the cathode material basically consists of particles in the form of secondary single crystal fusions. .
  • the “primary single crystal particles” refer to the primary particles constituting the positive electrode material, which usually have a morphology similar to a polyhedron, especially a cuboid-like morphology.
  • the size of the primary single crystal particles is usually not uniform, which helps to increase the tap density of the material.
  • the “secondary single crystal fusion body” refers to a fusion body formed by at least part of the above-mentioned primary single crystal particles fused, which is usually formed by not less than 5 primary single crystal particles.
  • the secondary single crystal fusion body exhibits irregularly shaped solid particles with a plurality of protrusions on the surface.
  • the positive electrode material has a layered crystal structure.
  • the SEM images of the positive electrode material are shown in FIGS. 3A and 3B, and the particle morphology of the positive electrode material is a secondary single crystal fusion formed by at least partial fusion of primary single crystal particles. body.
  • the primary single crystal particles have a cuboid-like morphology with different sizes; no less than 5 primary single crystal particles are fused with each other to form a secondary single crystal fusion.
  • the TEM image of the positive electrode material is shown in FIG. 3C.
  • Figure 3C further shows that the particle morphology of the positive electrode material is a fusion formed by at least partial fusion of primary single crystal particles.
  • the SEM image of the cross section of the positive electrode material is shown in FIG. 3D.
  • Figure 3D clearly shows that the particle morphology of the positive electrode material is a fusion formed by at least partial fusion of primary single crystal particles.
  • the average size of the primary single crystal particles is about 0.2-3 ⁇ m, and the average particle size of the secondary single crystal fusion is about 0.5-15 ⁇ m.
  • the average particle size can be determined by dynamic astigmatism.
  • the XRD pattern of the positive electrode material has characteristic diffraction peaks around 2 ⁇ angles of 18.6°, 36.5°, and 44.3°, respectively, wherein the intensity of the diffraction peaks around 2 ⁇ angles of 18.6° is the same as
  • the ratio of the intensities of the diffraction peaks with a 2 ⁇ angle around 44.3° is about 1.5 or more, and more preferably about 1.7 or more, and the diffraction peak intensity is calculated as the height of the diffraction peak.
  • the diffraction peaks of the positive electrode material are very sharp, indicating that the crystal structure of the positive electrode material is well developed; there are no impurity peaks on the spectrum, indicating that the positive electrode material has high purity .
  • the XRD pattern of the positive electrode material shown in FIG. 4 there are characteristic diffraction peaks at 2 ⁇ angles of 18.6°, 36.5°, and 44.3°, respectively. Among them, the intensity of the diffraction peaks at 2 ⁇ angles of 18.6° is the same as 2 ⁇ .
  • the ratio of the intensity of the diffraction peak near the angle of 44.3° is about 1.8; and the diffraction peak near the 2 ⁇ angle of 65° is split obviously, indicating that the positive electrode material has formed a good layered crystal structure.
  • this application provides a method for preparing a lithium battery cathode material, which includes the following steps:
  • the precursor is the lithium battery cathode material precursor according to the first aspect or the third aspect of the present application.
  • the characteristics of the lithium battery cathode material precursor provided in the step (I) are as described in the first aspect or the third aspect of the above text application, and the description will not be repeated here.
  • the step (I) further includes preparing the lithium battery cathode material precursor according to the method for preparing the lithium battery cathode material precursor described in the second aspect of the present application.
  • the characteristics of the method for preparing the lithium battery cathode material precursor are as described in the second aspect of the above application, and the description is not repeated here.
  • the inventor of the present application unexpectedly discovered that in the process of preparing the positive electrode material, by using the precursor of the present application containing sheet-like single crystal agglomerates and polyhedral single crystal particles, or by intermittently feeding a metal salt solution
  • the cathode material precursor is prepared by the method
  • the final prepared cathode material has a special morphology, and its particle morphology is a secondary single crystal fusion formed by at least partial fusion of primary single crystal particles. This special morphology gives the The positive electrode material has better electrochemical performance.
  • the lithium source used in this application is not specifically limited, and can be various lithium sources conventionally used in the preparation of lithium battery ternary cathode materials.
  • the lithium source used in step (II) is selected from at least one of lithium nitrate, lithium chloride, lithium carbonate, lithium hydroxide, and lithium acetate.
  • the molar ratio of the lithium source to the precursor is about 0.9-1.2:1, such as about 0.9:1, about 1.0:1, and about 1.1:1. , About 1.2:1, or within the numerical range formed by any two of these ratios.
  • the method of mixing in step (II) is not particularly limited, such as including but not limited to ball milling, shearing, grinding, mixing, etc., as long as the lithium source and the precursor of the lithium battery cathode material
  • the body can be mixed evenly.
  • the mixing time is about 1-4 hours.
  • step (II) can be carried out in a conventional manner used in the art for preparing lithium battery cathode materials.
  • the solid-phase reaction is performed by calcining the mixture of the precursor and the lithium source.
  • the roasting treatment can be carried out in a conventional manner, and there is no particular limitation on this in this application.
  • the roasting treatment includes a first roasting and a second roasting, wherein:
  • the first firing conditions preferably include: the firing temperature is about 300-600°C, for example, it can be about 300°C, about 350°C, about 400°C, about 450°C, about 500°C, about 550°C, about 600°C, Or within the numerical range formed by any two of these values, more preferably, the calcination temperature is about 450-550°C; the calcination time is about 1-10h, such as about 1h, about 2h, about 3h, about 4h, About 5h, about 6h, about 7h, about 8h, about 9h, about 10h, or within the range of any two of these values, more preferably, the calcination time is about 4-8h;
  • the second firing conditions preferably include: a firing temperature of about 650-1000°C, for example, about 650°C, about 700°C, about 750°C, about 800°C, about 850°C, about 900°C, about 950°C, About 1000°C, or within the range of any two of these values, more preferably, the firing temperature is about 750-900°C; the firing time is about 4-48h, for example, it can be about 4h, about 8h, or about 12h , About 16h, about 20h, about 24h, about 28h, about 32h, about 36h, about 40h, about 44h, about 48h, or within the range of any two of these values, more preferably, the roasting time is about 8-24h.
  • the heating rate of the heating process of heating to the temperature of the first baking and the second baking is preferably about 0.5-10° C./min, for example about 0.5° C./min, About 1°C/min, about 2°C/min, about 3°C/min, about 5°C/min, about 10°C/min, or within a numerical range formed by any two of these values.
  • the present invention preferably adopts a staged calcination process including first calcination and second calcination.
  • one stage calcination can be directly performed under the conditions used for the second calcination mentioned above, and good electrical properties can also be obtained. Chemical properties.
  • the present application provides a cathode material prepared by the method for preparing a cathode material for a lithium battery as described above.
  • the characteristics of the lithium battery cathode material according to the sixth aspect of the present application are as described in the fourth aspect of the above text application, and the description will not be repeated here.
  • the application provides the application of the lithium battery cathode material precursor or cathode material according to the application in the preparation of the lithium battery anode.
  • the method for preparing a lithium battery positive electrode using the lithium battery positive electrode material precursor or positive electrode material is well known in the art, and will not be described in detail here.
  • the present application provides a lithium battery positive electrode, comprising a positive electrode material, a binder, and a conductive agent, wherein the positive electrode material is the positive electrode material according to the fourth or sixth aspect of the present application.
  • the conductive agent and binder can be various conductive agents and binders conventionally used in the art.
  • the conductive agent can be acetylene black, carbon nanotubes, graphene, conductive polymer materials, etc.
  • the binder can be polyvinylidene fluoride, polytetrafluoroethylene, polyvinyl alcohol, etc., which will not be repeated in this application.
  • the amount of the conductive agent and the binder can also be conventional amounts in the art.
  • the mass content of the positive electrode material can be about 50-98%, and the mass of the conductive agent The content may be about 1-25%, and the mass content of the binder may be about 1-25%.
  • the lithium battery positive electrode can be prepared by various methods known in the art. This application is not particularly limited, and can be selected by those skilled in the art according to needs.
  • the positive electrode material, conductive agent, and binder can be uniformly mixed, coated, and sliced to obtain a lithium battery positive electrode.
  • the present application provides a lithium battery comprising a positive electrode, a negative electrode, an electrolyte, and a separator, wherein the positive electrode is the lithium battery positive electrode according to the eighth aspect of the present application.
  • the negative electrode, electrolyte, and separator can use those materials conventionally used in lithium batteries, and there is no strict limitation on this application.
  • the negative electrode can be selected from natural graphite, artificial graphite, soft carbon, hard carbon, mesophase microspheres, silicon, silicon carbon, lithium, etc.
  • the electrolyte can be selected from liquid electrolyte, gel electrolyte, solid electrolyte, etc.
  • the separator can be selected from polyethylene separators, polypropylene separators, polyethylene/propylene composite separators, polyimide separators, and the like.
  • this application provides the following technical solutions:
  • a cathode material precursor characterized in that the cathode material precursor comprises sheet-like single crystal aggregates and polyhedral single crystal particles;
  • I(001), I(100) and I(101) satisfy the following relationship: I(001)/I(100) is not less than 1.5, I(001) )/I(101) is not less than 1.2;
  • the chemical formula of the cathode material precursor is Ni x Co y M z (OH) 2 , and M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn And at least one of Al;
  • a method for preparing a precursor of a positive electrode material characterized in that the method comprises:
  • step (2) subjecting the product obtained in step (1) to solid-liquid separation and drying treatment to obtain the positive electrode material precursor;
  • the metal salt solution contains metal elements Ni, Co, and M, and M is selected from at least one of Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn, and Al;
  • the molar dosage ratio of Ni element, Co element and M element is (0.3-1):(0-0.5):(0-0.3), wherein the molar dosage of Co and M is not zero.
  • the metal salt contained in the metal salt solution is selected from at least one of metal sulfate, metal nitrate, metal acetate, and metal oxalate;
  • the concentration of the metal salt solution is 0.01 to 5 mol/L.
  • the concentration of the precipitation agent solution is 0.02-10 mol/L.
  • the complexing agent is selected from the group consisting of ammonium ion donors, ethanolamine complexing agents, aminocarboxylic acid complexing agents, hydroxylaminocarboxylic acid complexing agents and carboxylic acids At least one of salt complexing agents;
  • the concentration of the complexing agent solution is 0.01-15 mol/L.
  • step (1) the intermittent dripping process includes:
  • step (3) Repeat the intermittent dropwise addition process of step (2) until the end of the reaction.
  • reaction conditions include: temperature is 30-70°C, preferably 45-60°C; time is not less than 10h, preferably 24-72h;
  • the mixing is carried out under stirring conditions
  • the stirring speed is 50-1000 r/min.
  • a positive electrode material characterized in that the positive electrode material comprises the positive electrode material precursor described in item 1 or 8 and lithium element;
  • the molar ratio of the lithium element to the precursor of the positive electrode material is 0.9-1.2:1.
  • a positive electrode material characterized in that the morphology of the positive electrode material is a secondary single crystal fusion formed by at least partial fusion of primary single crystal particles;
  • the chemical formula of the cathode material is LiNi x Co y M z O 2
  • M is selected from Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn and Al At least one
  • the average particle size of the secondary single crystal fusion is 0.5-15 ⁇ m.
  • a method for preparing a positive electrode material characterized in that the method comprises:
  • step (2) After mixing the precursor obtained in step (1) with a lithium source, the positive electrode material is prepared through a solid phase reaction;
  • the metal elements in the metal salt solution contain Ni, Co and M;
  • M is selected from at least one of Fe, Cr, Cu, Ti, Mg, W, Mo, Nb, Zn, Sn, Zr, Ga, Mn and Al;
  • the molar dosage ratio of Ni element, Co element and M element is (0.3-1):(0-0.5):(0-0.3), wherein the molar dosage of Co and M is not zero.
  • step (1) the intermittent dripping method includes the intermittent dripping process including:
  • step (3) Repeat the intermittent dropwise addition process of step (2) until the end of the reaction.
  • reaction conditions include: a reaction temperature of 30-70°C, and a reaction time of not less than 10 hours;
  • reaction process is carried out under stirring conditions
  • the stirring rate is 50-1000 rpm.
  • step (2) the solid-phase reaction method includes roasting the mixture of the precursor and the lithium source
  • the roasting treatment includes a first roasting and a second roasting
  • the first firing conditions include: a firing temperature of 300-600°C, a firing time of 1-10h; and/or
  • the conditions for the second roasting include: the roasting temperature is 650-1000°C, and the roasting time is 4-48h.
  • the metal element in the metal salt solution is a combination of Ni, Co and Mn or a combination of Ni, Co and Al;
  • the metal salt in the metal salt solution is selected from at least one of metal sulfate, metal nitrate, metal acetate, and metal oxalate;
  • the concentration of the metal salt solution is 0.01 to 5 mol/L.
  • the precipitating agent is selected from at least one of NaOH, KOH and LiOH;
  • the concentration of the precipitation agent solution is 0.02-10 mol/L.
  • the complexing agent is selected from the group consisting of ammonium ion donors, ethanolamine complexing agents, aminocarboxylic acid complexing agents, and hydroxylaminocarboxylic acid complexing agents. At least one of a mixture and a carboxylate complexing agent;
  • the concentration of the complexing agent solution is 0.01-15 mol/L.
  • the lithium source is selected from at least one of lithium nitrate, lithium chloride, lithium carbonate, lithium hydroxide, and lithium acetate;
  • the molar ratio of the lithium source to the precursor is 0.9-1.2:1.
  • a lithium battery positive electrode characterized in that it comprises a positive electrode material, a binder and a conductive agent;
  • the positive electrode material is the positive electrode material according to any one of items 11, 12 or 21;
  • the content of the positive electrode material is 50-98% by weight
  • the content of the binder is 1-25% by weight
  • the amount of the conductive agent is 1-25% by weight.
  • the scanning electron microscope image was obtained by a scanning electron microscope of the ZEISS Merlin model of the German ZEISS company.
  • the X-ray diffraction (XRD) pattern was measured by the D8 Advance SS X-ray diffractometer of the German company Bruker.
  • the transmission electron microscope image is obtained by the spherical aberration correction transmission electron microscope of the FEI Titan Cubed Themis G2 300 model of Thermo Fisher Scientific.
  • the sample preparation process of the transmission electron microscope inspection is as follows: Take a small amount of powder sample and add it to ethanol solvent, after 15 minutes of ultrasonic dispersion at 140W power, suck the supernatant liquid and drop it on the copper mesh, dry the solvent on the copper mesh and put it into the sample bin To observe.
  • the composition of the precursor and the positive electrode material is measured by an inductively coupled plasma spectrometer (ICP-OES) of the Varian 725 ES model of Agilent Company in the United States.
  • ICP-OES inductively coupled plasma spectrometer
  • the cross-section sample preparation process of the positive electrode material is as follows: the positive electrode material: carbon black: PVDF (binder) is mixed uniformly according to the mass ratio of 90:5:5, and then coated on the aluminum foil , Vacuum drying at 80°C for 6h to obtain a pole piece containing a positive electrode material. Then use a clean blade to cut the pole piece, and stick the cut pole piece on the sample stage. In the three-ion beam section mode, use the 5kV acceleration voltage to process the pole piece for 2 hours to obtain a flat and clean section for scanning electron microscope observation.
  • the metal salt solutions used are all sulfate solutions.
  • a metal salt solution with a concentration of 2 mol/L of metal ions (where the molar ratio of nickel, cobalt and manganese is 8:1:1) is prepared; a NaOH solution with a concentration of 4 mol/L is prepared; and an aqueous ammonia solution with a concentration of 6 mol/L is prepared.
  • the prepared metal salt solution, NaOH solution and ammonia solution are simultaneously added dropwise to the reaction kettle under stirring to cause precipitation reaction.
  • the dropping rate of the metal salt solution is 60 mL/h; the dropping rate of the ammonia solution is 60 mL/h.
  • the pH of the reaction system is 11.
  • the stirring speed was controlled to 600 rpm, the reaction temperature was 55° C., and the reaction time was 48 h.
  • the precipitation reaction was terminated, the slurry was vacuum filtered, washed with deionized water three times, and dried in a vacuum drying oven at 120°C for 12 hours to obtain a positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.799:0.100:0.101.
  • the SEM images of the obtained positive electrode material precursor are shown in Figure 1A and Figure 1B. It can be seen from the figures that the morphology of the positive electrode material precursor is significantly different from the traditional polycrystalline spherical agglomerate.
  • the positive electrode material precursor is composed of sheet-like single crystal agglomerates and It is composed of polyhedral single crystal particles.
  • the XRD pattern of the positive electrode material precursor is shown in Fig. 2.
  • the diffraction peak of the positive electrode material precursor is very sharp, indicating that the crystal structure of the positive electrode material precursor is well developed, in which (001) and (101) crystal planes
  • the corresponding diffraction peak intensity is relatively high, especially the diffraction peak intensity corresponding to the (001) crystal plane is significantly stronger than other diffraction peak intensity, indicating that the (001) and (101) crystal planes of the precursor of the positive electrode material, especially (001) crystal plane, more fully exposed, I(001)/I(100) intensity ratio is 2.45, I(001)/I(101) intensity ratio is 1.45, I(101)/I(100) The intensity ratio is 1.69.
  • cathode material precursor Take 10g of the above-mentioned cathode material precursor, add lithium source LiOH ⁇ H 2 O so that the molar ratio of Li:(Ni+Co+Mn) is 1.02:1, and mix the two uniformly by ball milling for 2h, and then put them into the crucible for high temperature step by step Firing, the first step: heating from room temperature at 5°C/min to 450°C for 6 hours, and the second step: heating from 450°C at 5°C/min to 850°C for 12 hours, and then natural cooling to obtain the positive electrode material.
  • the SEM images of the positive electrode material are shown in FIGS. 3A and 3B. It can be seen from the figures that the particle morphology of the positive electrode material is a secondary single crystal fusion formed by at least partial fusion of primary single crystal particles.
  • the average size of the primary single crystal particles of the positive electrode material is 0.2-3 ⁇ m; the average particle size of the secondary single crystal fusion is 0.5-15 ⁇ m.
  • the TEM image of the cathode material is shown in FIG. 3C. It can be clearly seen from FIG. 3C that after the ultrasonic dispersion treatment of the sample preparation process, the particle morphology of the cathode material is still maintained at least by primary single crystal particles. Fusion formed by partial fusion.
  • the SEM image of the cross section of the positive electrode material is shown in FIG. 3D, and it can be seen more intuitively and clearly that the primary single crystal particles are fused and grown together to form secondary fusion particles.
  • the XRD pattern of the positive electrode material is shown in FIG. 4, the diffraction peak of the positive electrode material is very sharp, indicating that the crystal structure of the positive electrode material is well developed; there is no impurity peak on the pattern, indicating that the positive electrode material has high purity .
  • the XRD pattern of the positive electrode material there are characteristic diffraction peaks at 2 ⁇ angles of 18.6°, 36.5°, and 44.3°, respectively.
  • the intensity of the diffraction peaks at 2 ⁇ angles of 18.6° and 2 ⁇ angles of around 44.3°
  • the ratio of the intensities of the diffraction peaks is 1.8; and the diffraction peaks near the 2 ⁇ angle of 65° split obviously, indicating that the positive electrode material has formed a good layered crystal structure.
  • the negative electrode adopts a lithium piece
  • the electrolyte is a liquid electrolyte
  • the liquid electrolyte is composed of a solute, a solvent and additives, where the solute is LiPF 6 , the concentration is 1.2M, and the volume ratio of the solvent is 1:1:1
  • the above-mentioned battery components are packed into a lithium battery in a glove box.
  • the electrochemical performance of the lithium battery was measured, and the charge-discharge curve obtained at a rate of 0.1C is shown in Figure 5.
  • the specific charge capacity of the material is 224.6mAh/g
  • the specific discharge capacity is 206.9mAh/g
  • the first week efficiency can reach 92.1 %.
  • the cycle stability curve under 1C rate is shown in Fig. 6, the capacity retention rate after 80 cycles of cycling can reach 96.1%, and the cycle stability is excellent.
  • the rate performance results are shown in Figure 7. Even under the high rate condition of 10C, the discharge capacity of the material can reach about 120mAh/g.
  • metal ions (wherein, the molar ratio of nickel, cobalt and manganese is 18:1:1) a metal salt solution with a concentration of 2mol/L; prepare a NaOH solution with a concentration of 4mol/L; prepare an ammonia solution with a concentration of 6mol/L.
  • the prepared metal salt solution, NaOH solution and ammonia solution are simultaneously added dropwise to the reaction kettle under stirring to cause precipitation reaction.
  • the dropping rate of the metal salt solution is 60 mL/h; the dropping rate of the ammonia solution is 60 mL/h.
  • the pH of the reaction system is 11.
  • the stirring speed was controlled to 600 rpm, the reaction temperature was 55° C., and the reaction time was 48 h.
  • the precipitation reaction was terminated, the slurry was vacuum filtered, washed with deionized water three times, and dried in a vacuum drying oven at 120°C for 12 hours to obtain a positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.903:0.048:0.049.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.37, and the intensity ratio of I(001)/I(101) It is 1.48, and the intensity ratio of I(101)/I(100) is 1.60.
  • step Firing Take 10g of the above-mentioned cathode material precursor, add lithium source LiOH ⁇ H 2 O so that the molar ratio of Li:(Ni+Co+Mn) is 1.02:1, and mix the two uniformly by ball milling for 2h, and then put them into the crucible for high temperature step by step Firing, the first step: heating from room temperature at 10°C/min to 500°C for 4 hours, and the second step: heating from 500°C at 10°C/min to 750°C, holding for 8 hours, and then natural cooling to obtain the positive electrode material.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • a metal salt solution with a concentration of 2 mol/L of metal ions (wherein the molar ratio of nickel, cobalt and manganese is 3:1:1) is prepared; a NaOH solution with a concentration of 4 mol/L is prepared; and an aqueous ammonia solution with a concentration of 6 mol/L is prepared.
  • the prepared metal salt solution, NaOH solution and ammonia solution are simultaneously added dropwise to the reaction kettle under stirring to cause precipitation reaction.
  • the dropping rate of the metal salt solution is 60 mL/h; the dropping rate of the ammonia solution is 60 mL/h.
  • the pH of the reaction system is 11.
  • the stirring speed was controlled to 600 rpm, the reaction temperature was 55° C., and the reaction time was 48 h.
  • the precipitation reaction is terminated, the slurry is vacuum filtered, washed with deionized water for 3 times, and dried and dehydrated in a vacuum drying oven at 120° C. for 12 hours to obtain a positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.602:0.201:0.197.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.59, and the intensity ratio of I(001)/I(101) It is 1.22, and the intensity ratio of I(101)/I(100) is 1.30.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • metal ions (wherein, the molar ratio of nickel, cobalt and manganese is 8:1:1) a metal salt solution with a concentration of 3mol/L; prepare a NaOH solution with a concentration of 8mol/L; prepare an aqueous ammonia solution with a concentration of 10mol/L.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.797:0.098:0.105.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.98, and the intensity ratio of I(001)/I(101) It is 1.42, and the intensity ratio of I(101)/I(100) is 1.39.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • metal ions (wherein, the molar ratio of nickel, cobalt and manganese is 8:1:1) a metal salt solution with a concentration of 0.5mol/L; prepare a NaOH solution with a concentration of 2mol/L; prepare an ammonia solution with a concentration of 2mol/L .
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.802:0.101:0.097.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.87, and the intensity ratio of I(001)/I(101) It is 1.39, and the intensity ratio of I(101)/I(100) is 1.35.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • a metal salt solution with a concentration of 5 mol/L of metal ions (wherein the molar ratio of nickel, cobalt and manganese is 8:1:1) is prepared; a NaOH solution with a concentration of 10 mol/L is prepared; and an aqueous ammonia solution with a concentration of 15 mol/L is prepared.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.801:0.099:0.100.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.77, and the intensity ratio of I(001)/I(101) is It is 1.33, and the intensity ratio of I(101)/I(100) is 1.33.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • metal ions (wherein, the molar ratio of nickel, cobalt and manganese is 8:1:1) a metal salt solution with a concentration of 0.01mol/L; prepare a NaOH solution with a concentration of 0.02mol/L; prepare a solution with a concentration of 0.01mol/L Ammonia solution.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.799:0.103:0.098.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.71, and the intensity ratio of I(001)/I(101) It is 1.29, and the intensity ratio of I(101)/I(100) is 1.33.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was carried out according to the method described in Example 1, except that during the dropping process, by adjusting the dropping rate of the NaOH solution and controlling the pH of the system to 12, the positive electrode material precursor was obtained.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.797:0.102:0.101.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.65, and the intensity ratio of I(001)/I(101) It is 1.25, and the intensity ratio of I(101)/I(100) is 1.32.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was carried out according to the method described in Example 1, except that during the dropping process, the pH value of the system was controlled to 9 by adjusting the dropping rate of the NaOH solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.791:0.105:0.104.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.68, and the intensity ratio of I(001)/I(101) It is 1.26, and the intensity ratio of I(101)/I(100) is 1.33.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the reaction temperature was controlled to 70° C. during the dropping process to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.800:0.098:0.102.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.86, and the intensity ratio of I(001)/I(101) It is 1.38, and the intensity ratio of I(101)/I(100) is 1.35.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the reaction temperature was controlled to 30° C. during the dropping process to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.805:0.102:0.093.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.02, and the intensity ratio of I(001)/I(101) It is 1.44, and the intensity ratio of I(101)/I(100) is 1.40.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1. The specific results of the obtained discharge capacity, the first week efficiency and the capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the reaction time was 12 hours to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.792:0.104:0.104.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.81, and the intensity ratio of I(001)/I(101) It is 1.38, and the intensity ratio of I(101)/I(100) is 1.31.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was performed according to the method described in Example 1, except that the stirring speed was 50 r/min to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.789:0.108:0.103.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 1.62, and the intensity ratio of I(001)/I(101) It is 1.24, and the intensity ratio of I(101)/I(100) is 1.31.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the stirring speed was 1000 r/min to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.800:0.100:0.100.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.41, and the intensity ratio of I(001)/I(101) It is 1.51, and the intensity ratio of I(101)/I(100) is 1.60.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the cathode material was prepared according to the method described in Example 1, except that the first step of the step-by-step calcination: heating from room temperature at 5°C/min to 600°C for 1 hour, and the second step: from 600°C to 5°C/min. The temperature is raised to 750°C in min, and the temperature is kept for 48 hours to obtain the cathode material.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the cathode material was prepared according to the method described in Example 1, except that the first step of the step-by-step calcination: heating from room temperature at 5°C/min to 300°C for 10 hours, and the second step: from 300°C to 5°C/min. The temperature was raised to 1000°C in min, and the temperature was kept for 4 hours to obtain the positive electrode material.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the cathode material was prepared according to the method described in Example 1, except that one-step calcination was used, and the temperature was raised from room temperature to 850°C at a rate of 5° C./min, and the temperature was kept for 12 hours to obtain the cathode material.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the same concentration of KOH solution was used as the precipitation agent to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.799:0.101:0.100.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.43, and the intensity ratio of I(001)/I(101) It is 1.51, and the intensity ratio of I(101)/I(100) is 1.61.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the diethanolamine solution of the same concentration was used as the complexing agent to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.792:0.105:0.103.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.42, and the intensity ratio of I(001)/I(101) It is 1.58, and the intensity ratio of I(101)/I(100) is 1.53.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was performed according to the method described in Example 1, except that the same concentration of disodium edetate solution was used as the complexing agent to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.805:0.097:0.098.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.43, and the intensity ratio of I(001)/I(101) It is 1.55, and the intensity ratio of I(101)/I(100) is 1.57.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the sodium citrate solution of the same concentration was used as the complexing agent to obtain the cathode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.800:0.102:0.098.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.43, and the intensity ratio of I(001)/I(101) It is 1.54, and the intensity ratio of I(101)/I(100) is 1.58.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that the metal salt was a 2mol/L solution with a molar ratio of nickel, cobalt and aluminum of 8:1.5:0.5 to obtain a precursor of the positive electrode material.
  • the molar ratio of Ni:Co:Al in the obtained cathode material precursor is 0.802:0.153:0.045.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.44, and the intensity ratio of I(001)/I(101) It is 1.53, and the intensity ratio of I(101)/I(100) is 1.59.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was carried out according to the method described in Example 1, except that the metal salt was a 2mol/L solution with a molar ratio of nickel, cobalt and magnesium of 8:1:1 to obtain a positive electrode material precursor.
  • the molar ratio of Ni:Co:Mg in the obtained cathode material precursor is 0.801:0.102:0.097.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.44, and the intensity ratio of I(001)/I(101) It is 1.55, and the intensity ratio of I(101)/I(100) is 1.57.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was performed according to the method described in Example 1, except that 0.02 mol/L of TiSO 4 was additionally added to the metal salt solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn:Ti in the obtained cathode material precursor is 0.795:0.101:0.104:0.009.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.32, and the intensity ratio of I(001)/I(101) It is 1.49, and the intensity ratio of I(101)/I(100) is 1.56.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was performed according to the method described in Example 1, except that 0.01 mol/L of Cr 2 (SO 4 ) 3 was additionally added to the metal salt solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn:Cr in the obtained cathode material precursor is 0.798:0.103:0.099:0.011.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.29, and the intensity ratio of I(001)/I(101) It is 1.47, and the intensity ratio of I(101)/I(100) is 1.56.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • Example 2 The operation was performed according to the method described in Example 1, except that 0.02 mol/L Fe(NO 3 ) 3 ⁇ 9H 2 O was additionally added to the metal salt solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn:Fe in the obtained cathode material precursor is 0.803:0.096:0.101:0.010.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.26, and the intensity ratio of I(001)/I(101) It is 1.47, and the intensity ratio of I(101)/I(100) is 1.54.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that 0.02 mol/L CuSO 4 ⁇ 5H 2 O was additionally added to the metal salt solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn:Cu in the obtained cathode material precursor is 0.801:0.100:0.099:0.009.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.09, and the intensity ratio of I(001)/I(101) It is 1.45, and the intensity ratio of I(101)/I(100) is 1.44.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • the operation was performed according to the method described in Example 1, except that 0.02 mol/L of ZnSO 4 ⁇ H 2 O was additionally added to the metal salt solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn:Zn in the obtained cathode material precursor is 0.797:0.104:0.099:0.010.
  • the SEM image of the cathode material precursor is similar to Figure 1A and Figure 1B, and the XRD image is similar to Figure 2, where the intensity ratio of I(001)/I(100) is 2.13, and the intensity ratio of I(001)/I(101) It is 1.46, and the intensity ratio of I(101)/I(100) is 1.46.
  • the SEM image of the cathode material is similar to FIG. 3A and FIG. 3B, and the TEM image is similar to FIG. 3C.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1, and the specific results of the obtained discharge capacity, first week efficiency and capacity retention rate after 80 cycles are shown in Table 3.
  • This comparative example is used to illustrate the preparation and evaluation methods of cathode material precursors and cathode materials that are not in this application
  • the operation was performed according to the method of Example 1, except that the dripping process was continuous dripping of the metal solution, the precipitant solution and the complexing agent solution, and there was no intermittent dripping process of the metal solution to obtain the positive electrode material precursor.
  • the molar ratio of Ni:Co:Mn in the obtained cathode material precursor is 0.799:0.102:0.099.
  • the SEM image of the obtained cathode material precursor is shown in FIG. 8. It can be seen that the morphology of the cathode material precursor is polycrystalline spherical agglomerates, and the sphericity is good.
  • the XRD pattern is shown in Figure 9. It can be seen that the difference between the (001) crystal plane, the (100) crystal plane and the (101) crystal plane is small, and the intensity ratio of I(001)/I(100) is 1.19, the intensity ratio of I(001)/I(101) is 1.04, and the intensity ratio of I(101)/I(100) is 1.14.
  • the SEM image of the cathode material is shown in FIG. 10A. It can be seen that the morphology of the obtained cathode material is secondary micron polycrystalline spherical agglomerates composed of nano- or sub-micron primary particles with good sphericity.
  • FIG. 10B The TEM image of the positive electrode material is shown in FIG. 10B, where it can be clearly seen from FIG. 10B that after the ultrasonic treatment of the sample preparation process, the secondary micron polycrystalline spherical agglomerates of the positive electrode material are partially disintegrated, Produce discrete individual nanoparticles.
  • the electrochemical performance of the positive electrode material was evaluated according to the method described in Example 1.
  • the specific results of the discharge capacity, the first week efficiency and the capacity retention after 80 cycles are shown in Table 3, and the rate performance results are shown in FIG. 11.
  • Example 23 Ni 0.801 Co 0.102 Mg 0.097 Li 1.008 Ni 0.801 Co 0.102 Mg 0.097
  • Example 24 Ni 0.795 Co 0.101 Mn 0.104 Ti 0.009 Li 1.005 Ni 0.795 Co 0.101 Mn 0.104 Ti 0.009
  • Example 25 Ni 0.798 Co 0.103 Mn 0.099 Cr 0.011 Li 1.015 Ni 0.798 Co 0.103 Mn 0.099 Cr 0.011
  • Example 26 Ni 0.803 Co 0.096 Mn 0.101 Fe 0.010 Li 1.007 Ni 0.803 Co 0.096 Mn 0.101 Fe 0.010
  • Example 27 Ni 0.801 Co 0.100 Mn 0.099 Cu 0.009 Li 1.005 Ni 0.801 Co 0.100 Mn 0.099 Cu 0.009
  • Example 28 Ni 0.797 Co 0.104 Mn 0.099 Zn 0.010 Li 1.008 Ni 0.797 Co 0.104 Mn 0.099 Zn 0.010 Comparative example 1 Ni 0.799 Co 0.102 Mn 0.099 Li 1.010 Ni 0.799
  • Example 1 2.45 1.45 1.69
  • Example 2 2.37 1.48 1.60
  • Example 3 1.59 1.22 1.30
  • Example 4 1.98 1.42 1.39
  • Example 5 1.87 1.39 1.35
  • Example 6 1.77 1.33 1.33
  • Example 7 1.71 1.29 1.33
  • Example 8 1.65 1.25 1.32
  • Example 9 1.68 1.26 1.33
  • Example 10 1.86 1.38 1.35
  • Example 11 2.02 1.44 1.40
  • Example 12 1.81 1.38 1.31
  • Example 13 1.62 1.24 1.31
  • Example 14 2.41 1.51 1.60
  • Example 15 2.45 1.45 1.69
  • Example 16 2.45 1.45 1.69
  • Example 17 2.45 1.45 1.69
  • Example 18 2.43 1.51 1.61
  • Example 19 2.42 1.58 1.53
  • Example 20 2.43 1.55 1.57
  • Example 21 2.43 1.54 1.58
  • Example 22 2.44 1.53 1.59
  • Example 23 2.44 1.55 1.57
  • Example 24 2.32 1.49 1.56
  • Example 25 2.29 1.47 1.56
  • Example 26 2.26 1.47 1.54
  • Example 27 2.09 1.45 1.44
  • Example 28 2.13 1.46 1.46 Comparative example 1 1.19 1.04 1.14
  • Example 1 206.9 92.1 96.1
  • Example 2 204.7 91.4 95.1
  • Example 3 181.5 91.9 95.7
  • Example 4 201.5 91.2 94.9
  • Example 5 200.4 91.1 94.6
  • Example 6 199.3 90.9 94.1
  • Example 7 198.8 90.5 93.9
  • Example 8 197.9 90.3 93.1
  • Example 9 198.4 91.5 94.3
  • Example 10 200.1 91.2 94.2
  • Example 11 201.7 91.0 93.5
  • Example 12 199.5 90.7 92.8
  • Example 13 195.4 90.4 91.9
  • Example 14 205.1 92.0 95.9
  • Example 15 202.7 91.6 95.1
  • Example 16 203.1 91.5 95.7
  • Example 17 203.8 91.3 94.5
  • Example 18 206.8 92 95.8
  • Example 19 205.4 91.6 95.2
  • Example 21 206.1 91.9 95.8
  • Example 22 206.7 92 96.0
  • Example 23 206.4 91.9 95.9
  • Example 24 203.8 91.7 95.9
  • Example 25 203.5 92 95.4
  • Example 26 203.4 91.8 95.3
  • Example 27 202.4 91.4 95.9
  • Example 28 202.9 91.8 96 Comparative example 1 184.7 86.6 88.1
  • the lithium battery cathode material precursor of the present application is different from the precursor having the morphology of polycrystalline spherical aggregates, and contains sheet-like single crystal aggregates and polyhedrons.
  • Single crystal particles have more exposed areas of (001) crystal planes and (101) crystal planes; at the same time, the lithium battery cathode material of this application is different from polycrystalline spherical aggregate materials and dispersed single crystal particle materials.
  • the particulate material in the form of a secondary single crystal fusion formed by at least partially fused single crystal particles has better electrochemical performance, such as higher discharge capacity and first week efficiency, and cycle performance has also been improved.
  • the rate performance of the lithium battery cathode material precursor and cathode material of the present application is significantly better, and the discharge capacity is obvious at a high rate.
  • the discharge capacity of the positive electrode material obtained using the precursor material of the present application is about twice that of the positive electrode material obtained in the comparative example.

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Abstract

一种锂电池正极材料前驱体、其制备方法及应用，所述前驱体具有化学式Ni xCo yM z(OH) 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3；其中，所述前驱体包含片状单晶团聚体和多面体单晶颗粒，并且所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：I(001)/I(100)不低于约1.5，且I(001)/I(101)不低于约1.2。采用所述前驱体制备得到的锂电池正极材料具有提高的电化学性能。

Description

锂电池正极材料前驱体、其制备方法及应用
相关申请的交叉引用
本申请要求2019年10月17日提交的、申请号为201910990467.8、名称为“正极材料前驱体及其制备方法和正极材料及其应用”的专利申请的优先权，以及2019年10月17日提交的、申请号为201910989951.9、名称为“正极材料及其制备方法、锂电池正极及其应用”的专利申请的优先权，它们的内容经此引用全文并入本文。
技术领域
本申请涉及锂电池领域，具体涉及一种锂电池正极材料前驱体、其制备方法及应用。
背景技术
锂离子电池(本申请中也称为“锂电池”)具有能量密度大、输出电压高、自放电小、循环性能优异、无记忆效应等优点，广泛应用于便携式电子产品、电动工具和电动汽车等领域。尤其近年来各国政府出台的新能源汽车推广政策不断升级，催生了动力型锂电池的爆发式发展。
正极材料是锂电池的关键核心部件，它不仅决定了锂电池的能量密度等关键核心指标，同时占整个电池约40％的成本。随着人们对电动汽车续航里程要求的不断提升，具有更高能量密度的三元正极材料逐渐成为主流的乘用车用正极材料。
锂电池正极材料的形貌对其电化学性能有着重要的影响。目前商业化的三元正极材料的形貌主要有两种。一种形貌是由纳米级或亚微米级一次颗粒团聚形成的二次微米多晶球形团聚体颗粒，具有这种形貌的正极材料的细小的多晶颗粒可与电解液充分接触，倍率性能较好，但细小的多晶颗粒容易与电解液发生副反应，导致过渡金属在电解液中溶解，电池的循环稳定性较差。另一种形貌是分散型的单晶颗粒，具有这种形貌的正极材料具有稳定的晶体结构，充放电过程中与电解液的兼容性好，并且循环过程中不易破碎，电池的循环稳定性好，但由于分散型单晶颗粒的尺寸较大，容量和倍率性能较差。
对于三元正极材料来说，其形貌基本由其前驱体决定。目前商业化的三元正极材料前驱体的形貌主要是由纳米级或亚微米级一次颗粒团 聚形成的二次微米多晶球形团聚体颗粒。例如，中国专利申请公开CN107915263A公开了具有尺寸在3.5-4.0μm的二次微米多晶球形团聚体形貌的前驱体材料。这类材料在充放电过程中，细小的一次颗粒会与电解液接触反应，导致多晶材料的容量和首周效率不高，难以满足在动力电池中的实际应用需求。
发明内容
为了克服现有技术中存在的问题，本申请的一个目的是提供一种新型的锂电池正极材料前驱体、其制备方法及应用，采用所述前驱体制备得到的锂电池正极材料具有提高的电化学性能。
为了实现上述目的，一方面，本申请提供了一种锂电池正极材料前驱体，所述前驱体具有化学式Ni xCo yM z(OH) 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且x、y和z的取值满足电中性规则；
其中，所述前驱体包含片状单晶团聚体和多面体单晶颗粒，并且所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：
I(001)/I(100)不低于约1.5，且
I(001)/I(101)不低于约1.2，
优选地，I(101)/I(100)不低于约1.3，
其中I(001)、I(100)和I(101)分别表示以衍射峰高度计的(001)晶面、(100)晶面和(101)晶面的衍射峰强度。
另一方面，本申请提供了一种锂电池正极材料前驱体的制备方法，包括如下步骤：
(1)将金属盐溶液与沉淀剂溶液和络合剂溶液混合进行反应，其中所述沉淀剂溶液和络合剂溶液以连续方式进料到反应体系中，而所述金属盐溶液以间歇方式进料到反应体系中；
(2)将步骤(1)得到的产物进行固液分离和干燥处理，得到所述前驱体；
其中，所述金属盐溶液中的金属包括Ni、Co和M，所述金属M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种，金属Ni、Co与M的摩尔用量比为约(0.3-1)∶(0-0.5)∶(0-0.3)，其中Co和M的摩尔用量不为零。
再一方面，本申请提供了通过本申请的锂电池正极材料前驱体制备方法制得的锂电池正极材料前驱体。
再一方面，本申请提供了一种锂电池正极材料，所述正极材料具有化学式Li aNi xCo yM zO 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.9≤a≤1.2，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且a、x、y和z的取值满足电中性规则；
其中，所述正极材料包含由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒。
再一方面，本申请提供了一种锂电池正极材料的制备方法，包括如下步骤：
(I)提供锂电池正极材料的前驱体；
(II)将所述前驱体和锂源混合进行固相反应，得到所述正极材料；
其中所述前驱体为根据本申请的锂电池正极材料前驱体。
再一方面，本申请提供了通过本申请的锂电池正极材料制备方法制得的锂电池正极材料。
再一方面，本申请提供了一种锂电池正极，包含正极材料、粘结剂和导电剂，其中所述正极材料为根据本申请的锂电池正极材料。
又一方面，本申请提供了一种锂电池，包含正极、负极、电解质和隔膜，其中所述正极为根据本申请的锂电池正极。
本申请的锂电池正极材料前驱体区别于具有多晶球形团聚体形貌的三元正极材料前驱体，包含片状单晶团聚体和多面体单晶颗粒，其(001)晶面和(101)晶面的暴露面积更多，从而赋予所述正极材料前驱体以更好的电化学性能。
本申请的锂电池正极材料区别于现有的多晶球形团聚体和分散型单晶颗粒形式的正极材料，包含由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒。该正极材料兼具多晶球形团聚体和分散型单晶三元正极材料的优点，具有放电容量高、首周效率高、倍率性能好和循环稳定性好的特点。采用该正极材料的锂电池，在0.1C倍率下，放电容量可达206.9mAh/g，首周效率可达92.1％；在1C倍率下，循环80圈后的容量保持率可达96.1％；在10C倍率下，放电容量可以达到120mAh/g。
附图说明
图1A是本申请实施例1制得的正极材料前驱体的SEM图；
图1B是本申请实施例1制得的正极材料前驱体的SEM图；
图2是本申请实施例1制得的正极材料前驱体的XRD图；
图3A是本申请实施例1制得的正极材料的SEM图；
图3B是本申请实施例1制得的正极材料的SEM图；
图3C是本申请实施例1制得的正极材料的TEM图；
图3D是本申请实施例1制得的正极材料的截面的SEM图；
图4是本申请实施例1制得的正极材料的XRD图；
图5是本申请实施例1的正极材料组装成的锂电池在0.1C倍率下的充放电曲线；
图6是本申请实施例1的正极材料组装成的锂电池在0.1C倍率下循环容量保留曲线；
图7是本申请实施例1的正极材料组装成的锂电池在不同倍率下的容量结果；
图8是本申请对比例1制得的正极材料前驱体的SEM图；
图9是本申请对比例1制得的正极材料前驱体的XRD图；
图10A是本申请对比例1制得的正极材料的SEM图；
图10B是本申请对比例1制得的正极材料的TEM图；
图11是本申请对比例1的正极材料组装成的锂电池在不同倍率下的容量结果；
附图标记
A片状单晶团聚体 B多面体单晶颗粒。
具体实施方式
以下将通过具体的实施方式对本发明作出进一步的详细描述，应当理解的是，此处所描述的具体实施方式仅用于说明和解释本发明，但不以任何方式限制本发明。
在本文中所披露的任何具体数值(包括数值范围的端点)都不限于该数值的精确值，而应当理解为还涵盖了接近该精确值的值。并且，对于所披露的数值范围而言，在该范围的端点值之间、端点值与范围内的具体点值之间，以及各具体点值之间可以任意组合而得到一个或 多个新的数值范围，这些新的数值范围也应被视为在本文中具体公开。
除非另有说明，本文所用的术语具有与本领域技术人员通常所理解的相同的含义，如果术语在本文中有定义，且其定义与本领域的通常理解不同，则以本文的定义为准。
在本申请中，所谓“满足电中性规则”是指相应化学式中所有元素的化合价的代数和为零。
在本申请中，术语“团聚体”是指多个颗粒通过物理相互作用(如静电力和范德华力等)聚集在一起形成的聚集体，其颗粒间相互作用力较弱，因而容易在外力作用下崩解。
在本申请中，术语“融合体”是指多个颗粒至少部分熔融结合在一起形成的整体结构，其中各个颗粒已经彼此融合成为一体，因而不容易被外力所破坏。
在本申请中，表述“至少部分融合”是指颗粒形体的至少一部分与其他颗粒的至少一部分发生融合，从而形成为一体。
根据本申请，所述“以间歇方式进料”是指所述金属盐溶液分多次(例如，2、3、4、5、6次等)间断地进料到反应体系中，优选每次进料均以连续方式进行，特别是以匀速连续方式进行，直至预定的时间或者加完预定量的物料。
本申请中，除了明确说明的内容之外，未提到的任何事宜或事项均直接适用本领域已知的那些而无需进行任何改变。而且，本文描述的任何实施方式均可以与本文描述的一种或多种其他实施方式自由结合，由此形成的技术方案或技术思想均视为本发明原始公开或原始记载的一部分，而不应被视为是本文未曾披露或预期过的新内容，除非本领域技术人员认为该结合明显不合理。
在本文中提及的所有专利和非专利文献，包括但不限于教科书和期刊文章等，均通过引用方式全文并入本文。
在第一方面，本申请提供了一种锂电池正极材料前驱体，所述前驱体包含片状单晶团聚体和多面体单晶颗粒，并且所述前驱体的XRD图中，I(001)、I(100)和I(101)之间满足以下关系：
I(001)/I(100)不低于约1.5，优选不高于约10，且
I(001)/I(101)不低于约1.2，优选不高于约5，
优选地，I(101)/I(100)不低于约1.3，优选不高于约5；
所述前驱体具有化学式Ni xCo yM z(OH) 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且x、y和z的取值满足电中性规则。
根据本申请，所述前驱体包含片状单晶团聚体和多面体单晶颗粒，优选地，所述前驱体基本由片状单晶团聚体和多面体单晶颗粒组成。
根据本申请，所述“片状单晶团聚体”是指一次形貌为片状单晶，二次形貌为上述片状单晶团聚形成的团聚体形式的颗粒；所述“多面体单晶颗粒”是指形貌为多面体的单晶颗粒。
根据本申请，所述I(001)是指(001)晶面的衍射峰强度；所述I(100)是指(100)晶面的衍射峰强度；所述I(101)是指(101)晶面的衍射峰强度，其中所述的衍射峰强度以衍射峰的高度计。
在某些优选的实施方式中，在所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：I(001)/I(100)不低于约1.5且不高于约10，例如不高于约5或不高于约3；I(001)/I(101)不低于约1.2且不高于约5，例如不高于约3或不高于约2，并且I(101)/I(100)不低于约1.3且不高于约5，例如不高于约3或不高于约2。
在某些优选的实施方式中，在所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：I(001)/I(100)不低于约1.8，I(001)/I(101)不低于约1.3，且I(101)/I(100)不低于约1.5。
在特别优选的实施方式中，在所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：I(001)/I(100)不低于约1.8且不高于约10，例如不高于约5或不高于约3；I(001)/I(101)不低于约1.3且不高于约5，例如不高于约3或不高于约2；并且I(101)/I(100)不低于约1.5且不高于约5，例如不高于约3或不高于约2。
在优选的实施方式中，在所述前驱体的化学式中，0.6≤x≤0.95，0.025≤y≤0.2，0.025≤z≤0.2。
在优选的实施方式中，M为Mn、Al和Mg中的至少一种，或者为Mn、Al和Mg中的至少一种与选自Fe、Cr、Cu、Ti、W、Mo、Nb、Zn、Sn、Zr和Ga中的至少一者的组合。例如，所述前驱体可以具有化学式Ni xCo yMn z(OH) 2、Ni xCo yAl z(OH) 2或Ni xCo yMg z(OH) 2，其中x、y和z的定义如前所述。
在本申请的一个优选的实施方式中，所述前驱体的SEM图如图1A和图1B所示。从图1A和1B中可以看出，本申请所述的锂电池正极材料前驱体中包含片状单晶团聚体和多面体单晶颗粒。从图2中可以看出，所述正极材料前驱体至少具有三个衍射峰，包括位于2θ角为19.6°附近的(001)衍射峰、位于2θ角为33.4°附近的(100)衍射峰和位于2θ角为38.8°附近的(101)衍射峰。所述前驱体的衍射峰尖锐，表明晶体结构发育良好，并且(001)和(101)晶面衍射峰强度较高，表明前驱体中(001)和(101)晶面，特别是(001)晶面，暴露得更加充分。本申请的锂电池正极材料前驱体与现有的具有多晶球形团聚体形貌的正极材料前驱体之间存在明显的差别，现有多晶球形团聚体的形貌是球形或类球形，衍射峰的强度(尤其是(001)和/或(101)晶面的强度)也明显低于本申请所述的前驱体材料。
根据本申请，所述正极材料前驱体的粒径(D50)大小优选为2-12μm，粒径大小的测定方法为动态光散射技术。
在第二方面，本申请提供了一种锂电池正极材料前驱体的制备方法，包括如下步骤：
(1)将金属盐溶液与沉淀剂溶液和络合剂溶液混合进行反应，其中所述沉淀剂溶液和络合剂溶液以连续方式进料到反应体系中，而所述金属盐溶液以间歇方式进料到反应体系中；
(2)将步骤(1)得到的产物进行固液分离和干燥处理，得到所述正极材料前驱体；
其中，所述金属盐溶液中的金属包括Ni、Co和M，所述金属M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种，金属Ni、Co与M的摩尔用量比为约(0.3-1)∶(0-0.5)∶(0-0.3)，其中Co和M的摩尔用量不为零。
本申请的发明人在研究过程中意外发现，在制备锂电池正极材料前驱体的过程中，连续进料原料的方式获得的前驱体的形貌基本为多晶球形团聚体，而通过间歇进料金属盐溶液的方式制备前驱体时，能够获得包含片状单晶团聚体和多面体单晶颗粒的前驱体，这种具有特殊形貌的前驱体具有更好的电化学性能。
在优选的实施方式中，所述金属盐溶液中金属Ni、Co与M的摩尔用量比为约(0.6-0.95)∶(0.025-0.2)∶(0.025-0.2)。
在本申请中，所述金属盐溶液可以为本领域常规用于锂电池正极材料或正极材料前驱体制备的金属盐溶液。优选地，金属M为Mn、Al和Mg中的至少一种，或者为Mn、Al和Mg中的至少一种与选自Fe、Cr、Cu、Ti、W、Mo、Nb、Zn、Sn、Zr和Ga中的至少一者的组合。例如，所述金属盐溶液中的金属可以为Ni、Co和Mn的组合、Ni、Co和Al的组合或者Ni、Co和Mg的组合。
在本申请中，形成所述金属盐溶液的金属盐的种类没有特别的限制。优选地，所述金属盐选自硫酸盐、硝酸盐、醋酸盐、氯化物和草酸盐中的至少一种。例如，金属Ni的盐可以选自硫酸镍、硝酸镍、醋酸镍、草酸镍和氯化镍中的至少一种；金属Co的盐可以选自硝酸钴、氯化钴、乙酸钴和硫酸钴中的至少一种；金属Mn的盐可以选自硫酸锰、硝酸锰、醋酸锰和氯化锰中的至少一种；金属Al的盐可以选自硝酸铝、氯化铝、乙酸铝和硫酸铝中的至少一种；金属Mg的盐可以选自硝酸镁、氯化镁、乙酸镁和硫酸镁中的至少一种。
在优选的实施方式中，以金属元素计，所述金属盐溶液的浓度为约0.01-5mol/L，比如可以为约0.01mol/L、约0.1mol/L、约0.5mol/L、约1mol/L、约2mol/L、约3mol/L、约4mol/L、约5mol/L，或者在这些数值中任意两个构成的数值范围内，更优选为约0.5-3mol/L，进一步优选为约1-2mol/L。
在本申请中，所述沉淀剂的种类没有特别的限制。优选地，所述沉淀剂可以选自NaOH、KOH和LiOH中的至少一种。
在本申请中，所述沉淀剂溶液的浓度没有特别的限制。优选地，所述沉淀剂溶液的浓度可以为约0.02-10mol/L，比如可以为约0.02mol/L、约0.1mol/L、约0.5mol/L、约1mol/L、约2mol/L、约3mol/L、约4mol/L、约5mol/L、约6mol/L、约7mol/L、约8mol/L、约9mol/L、约10mol/L，或者在这些数值中任意两个构成的数值范围内，更优选为约2-8mol/L，进一步优选为约2-6mol/L。
在本申请中，所述络合剂的种类没有特别的限制，可以是任何能够在水溶液中与Ni、Co和M形成络合物的化合物。优选地，所述络合剂选自铵离子供体、乙醇胺类络合剂、氨基羧酸类络合剂、羟氨基羧酸类络合剂和羧酸盐类络合剂中的至少一种。例如，所述铵离子供体优选选自氨水、草酸铵、碳酸铵和氢氧化铵中的至少一种；所述乙醇 胺类络合剂优选为二乙醇胺；所述氨基羧酸类络合剂优选选自氮川三乙酸钠(NTA)、乙二胺四乙酸及其盐(EDTA)和二乙烯三胺五乙酸(DTPA)中的至少一种；所述羟氨基羧酸类络合剂优选选自羟乙二胺四乙酸(HEDTA)、乙二醇双(β-二氨基乙基)乙醚-N，N，N’N’-四乙酸(EGTA)及其盐和二羟基甘氨酸及其盐中的至少一种；所述羧酸盐类络合剂优选选自草酸及其盐、酒石酸及其盐、柠檬酸及其盐、葡萄糖酸及其盐、羧甲基羟基丙二酸(CMOM)及其盐、羧甲基羟基丁二酸(CMOS)及其盐和羟乙基氨基乙酸(DHEG)及其盐中的至少一种。
在本申请中，所述络合剂溶液的浓度没有特别的限制。优选地，所述络合剂溶液的浓度为约0.01-15mol/L，比如可以为约0.01mol/L、约0.1mol/L、约0.5mol/L、约1mol/L、约2mol/L、约3mol/L、约4mol/L、约5mol/L、约6mol/L、约7mol/L、约8mol/L、约9mol/L、约10mol/L、约11mol/L、约12mol/L、约13mol/L、约14mol/L、约15mol/L，或者在这些数值中任意两个构成的数值范围内，进一步优选为约2-10mol/L，更优选为约2-6mol/L。
根据本申请，步骤(1)中的反应条件优选包括：温度为约30-70℃，优选为约45-60℃；时间不低于约10h，优选为约24-72h；pH为约9-14，优选为约9-12，并且所述金属盐溶液至少分两次进料到所述反应体系中。通过控制反应的温度和/或时间，能够控制前驱体晶体的生长。
在优选的实施方式中，所述步骤(1)进一步包括：
(1a)将所述金属盐溶液、所述沉淀剂溶液和所述络合剂溶液连续进料到反应器中，使它们混合并发生反应，持续约2-12h，优选约3-8h；
(1b)暂停所述金属盐溶液的进料约0.5-4h，优选约1-3h；
(1c)重复步骤(1a)-(1b)，直至反应结束。
在更进一步优选的实施方式中，每一步骤(1a)的持续时间不超过步骤(1)总时间的约5/6，优选不超过约2/3。
根据本申请，在步骤(1)中，所述反应体系的pH控制在约9-14的范围内，优选在约9-12的范围内。特别地，在步骤(1a)中，所述反应体系的pH控制在约9-12范围内，优选控制在约10-11.5范围内。
根据本申请，所述金属盐、沉淀剂和络合剂的用量可以在较宽范围内进行选择，通常以摩尔计，所述金属盐、沉淀剂和络合剂的用量比 可以为约1∶(1.5-3)∶(0.5-6)。
根据本申请，各反应物料的进料速率可以在较宽范围内进行选择，只要所述进料速率能够满足使得步骤(1)、特别是步骤(1a)中反应体系的pH值保持在设定范围内即可。通常，可以基于反应物料的总量选择相匹配的反应器尺寸，再根据反应器的尺寸和反应时间等因素来确定适合的进料速率，这是本领域技术人员基于本申请的公开内容容易确定的。
根据本申请，在步骤(1)的连续进料阶段(例如步骤(1a)中)，以体积计，所述金属盐溶液和络合剂溶液的进料速率之比通常可以为约0.5-6，所述沉淀剂的进料速率控制为使反应体系的pH值保持在设定范围内。
在某些优选实施方式中，以1L的金属盐溶液总量为基准，金属盐溶液的进料速率为约10-200mL/h；以1L的沉淀剂溶液总量为基准，沉淀剂溶液的进料速率为约10-200mL/h；以1L的络合剂溶液总量为基准，络合剂溶液的进料速率为约10-200mL/h。本领域技术人员可以根据pH的需要控制进料速率。
需要说明的是，本申请所述的以1L的金属盐溶液总量为基准，金属盐溶液的进料速率为约10-200mL/h，指的是在反应器尺寸与反应物料总量相匹配的情况下，相对于每1L金属盐溶液，金属盐溶液的进料速率为约10-200mL/h。例如，当金属盐溶液总量为0.5L时，金属盐溶液的进料速率为约5-100mL/h；而当金属盐溶液总量为5L时，金属盐溶液的进料速率为约50-1000mL/h。
根据本申请，各反应物料的进料方式没有特别的限制，可以采用本领域的常规方式进行，例如可以通过滴加方式进行。
在优选的实施方式中，步骤(1)的混合在搅拌条件下进行，更优选地，所述搅拌速度为约50-1000r/min，比如可以为约50r/min、约80r/min、约100r/min、约200r/min、约300r/min、约400r/min、约500r/min、约600r/min、约700r/min、约800r/min、约900r/min、约1000r/min，或者在这些数值中的任意两个构成的数值范围内，进一步优选为约600-1000r/min。
在本申请中，优选在对步骤(1)得到的产物进行固液分离之前，先对其进行冷却处理。经所述冷却处理后，所述产物的温度优选降至 室温，比如可以为约25℃。
本申请中，步骤(2)所述的固液分离可以采用任何适合的方式进行，只要能够将制得的前驱体分离出来即可，例如，可以采用过滤或离心的方式。
在本申请中，优选地，对固液分离得到的产物进行洗涤处理。
在本申请中，步骤(2)所述的干燥处理可以采用任何本领域常规的方式进行，比如可以为真空干燥、风干、冷冻干燥或烘干。所述干燥处理的条件可以在较宽范围内进行选择，例如：温度为约70-150℃，时间为约4-16h。
在第三方面，本申请提供了通过上述锂电池正极材料前驱体制备方法制得的锂电池正极材料前驱体。
根据本申请第三方面的锂电池正极材料前驱体的特征如在上文本申请的第一方面中所述，在此不再重复说明。
在第四方面，本申请提供了一种锂电池正极材料，该正极材料包含由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒；
所述正极材料具有化学式Li aNi xCo yM zO 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.9≤a≤1.2，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且a、x、y和z的取值满足电中性规则。
根据本申请，所述正极材料包含由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒，优选地，所述正极材料基本由所述二次单晶融合体形式的颗粒组成。
根据本申请，所述“一次单晶颗粒”是指组成所述正极材料的初次颗粒，其通常具有近似多面体的形貌，特别是类长方体形貌。所述一次单晶颗粒的尺寸通常并不均一，这有助于提升材料的振实密度。所述“二次单晶融合体”是指上述一次单晶颗粒至少部分融合形成的融合体，其通常由不少于5个一次单晶颗粒形成。在某些具体实施方式中，所述二次单晶融合体呈现为表面具有复数个突起的形状不规则的实心颗粒。
在优选的实施方式中，所述正极材料具有层状晶体结构。
在本申请的一个优选的实施方式中，所述正极材料的SEM图如图3A和图3B所示，该正极材料的颗粒形貌为由一次单晶颗粒至少部分 融合形成的二次单晶融合体。特别地，所述一次单晶颗粒具有类长方体的形貌，尺寸大小不一；不少于5个一次单晶颗粒彼此融合在一起，形成二次单晶融合体。所述正极材料的TEM图如图3C所示。图3C进一步表明所述正极材料的颗粒形貌是由一次单晶颗粒至少部分融合形成的融合体。所述正极材料的截面的SEM图如图3D所示。图3D更加清晰地表明所述正极材料的颗粒形貌是由一次单晶颗粒至少部分融合形成的融合体。
在优选的实施方式中，所述一次单晶颗粒的平均尺寸为约0.2-3μm，所述二次单晶融合体的平均粒径为约0.5-15μm。根据本申请，所述平均粒径可通过动态散光射技术进行测定。
在优选的实施方式中，所述正极材料的XRD图谱中，在2θ角为18.6°、36.5°和44.3°附近分别具有特征衍射峰，其中，在2θ角为18.6°附近的衍射峰的强度与2θ角为44.3°附近的衍射峰的强度的比值在约1.5以上，更优选在约1.7以上，所述衍射峰强度以衍射峰的高度计。
在优选的实施方式中，如图4所示，所述正极材料的衍射峰非常尖锐，表明所述正极材料的晶体结构发育良好；图谱上没有杂峰，说明所述正极材料具有较高的纯度。在图4所示的所述正极材料的XRD图谱中，在2θ角为18.6°、36.5°和44.3°附近分别具有特征衍射峰，其中，在2θ角为18.6°附近的衍射峰的强度与2θ角为44.3°附近的衍射峰的强度的比值为约1.8；并且在2θ角为65°附近的衍射峰分裂明显，表明所述正极材料形成了良好的层状晶体结构。
在第五方面，本申请提供了一种锂电池正极材料的制备方法，包括如下步骤：
(I)提供锂电池正极材料的前驱体；
(II)将所述前驱体和锂源混合进行固相反应，得到所述正极材料；
其中所述前驱体为根据本申请第一方面或第三方面所述的锂电池正极材料前驱体。
根据本申请的这一方面，所述步骤(I)中提供的锂电池正极材料前驱体的特征如在上文本申请的第一方面或第三方面中所述，在此不再重复说明。
在优选的实施方式中，所述步骤(I)进一步包括按照本申请第二 方面所述的锂电池正极材料前驱体制备方法制备所述锂电池正极材料的前驱体。在该优选实施方式中，制备所述锂电池正极材料前驱体的方法的特征如在上文本申请的第二方面中所述，在此不再重复说明。
本申请的发明人在研究过程中意外发现，在制备正极材料的过程中，通过使用本申请的含有片状单晶团聚体和多面体单晶颗粒的前驱体，或者通过间歇进料金属盐溶液的方式来制备正极材料前驱体时，最终制备得到的正极材料具有特殊的形貌，其颗粒形貌为由一次单晶颗粒至少部分融合形成的二次单晶融合体，这种特殊形貌赋予所述正极材料更好的电化学性能。
本申请所用的锂源没有特定的限制，可以是锂电池三元正极材料的制备中常规使用的各种锂源。在优选的实施方式中，步骤(II)中所用的锂源选自硝酸锂、氯化锂、碳酸锂、氢氧化锂和醋酸锂中的至少一种。
在进一步优选的实施方式中，以金属元素计，所述锂源与所述前驱体的摩尔比为约0.9-1.2∶1，比如可以为约0.9∶1、约1.0∶1、约1.1∶1、约1.2∶1，或者在这些比值中任意两个构成的数值范围内。
在本申请中，步骤(II)中所述混合的方式没有特别的限制，比如包括但不限于球磨、剪切、研磨、混料等，只需满足使锂源和所述锂电池正极材料前驱体混合均匀即可。优选地，所述混合时间为约1-4h。
在本申请中，步骤(II)中所述的固相反应可以通过本领域中用于制备锂电池正极材料的常规方式进行。
在优选的实施方式中，所述固相反应通过对所述前驱体和所述锂源的混合物进行焙烧处理来进行。所述焙烧处理可以按照常规方式进行，本申请对此没有特别的限制。
在进一步优选的实施方式中，所述焙烧处理包括第一焙烧和第二焙烧，其中：
所述第一焙烧的条件优选包括：焙烧温度为约300-600℃，比如可以为约300℃、约350℃、约400℃、约450℃、约500℃、约550℃、约600℃，或者在这些数值中任意两个构成的数值范围内，更优选地，焙烧温度为约450-550℃；焙烧时间为约1-10h，比如可以为约1h、约2h、约3h、约4h、约5h、约6h、约7h、约8h、约9h、约10h，或者在这些数值中任意两个构成的数值范围内，更优选地，焙烧时间为约 4-8h；
所述第二焙烧的条件优选包括：焙烧温度为约650-1000℃，比如可以为约650℃、约700℃、约750℃、约800℃、约850℃、约900℃、约950℃、约1000℃，或者在这些数值中任意两个构成的数值范围内，更优选地，焙烧温度为约750-900℃；焙烧时间为约4-48h，比如可以为约4h、约8h、约12h、约16h、约20h、约24h、约28h、约32h、约36h、约40h、约44h、约48h，或者在这些数值中任意两个构成的数值范围内，更优选地，焙烧时间为约8-24h。
在该优选实施方式中，对于升温至所述第一焙烧和第二焙烧的温度的升温过程的升温速率没有特别的限制，优选为约0.5-10℃/min，例如为约0.5℃/min、约1℃/min、约2℃/min、约3℃/min、约5℃/min、约10℃/min，或者在这些数值中的任意两个构成的数值范围内。
本发明为了得到更好的电化学性能，优选采用包括第一焙烧和第二焙烧的分段焙烧工艺，但是也可以直接在上述第二焙烧所用的条件下进行一段焙烧，也可以得到良好的电化学性能。
在第六方面，本申请提供了通过如上所述的锂电池正极材料制备方法制得的正极材料。
根据本申请第六方面的锂电池正极材料的特征如在上文本申请的第四方面中所述，在此不再重复说明。
在第七方面，本申请提供了根据本申请的锂电池正极材料前驱体或正极材料在制备锂电池正极中的应用。
采用所述锂电池正极材料前驱体或正极材料制备锂电池正极的方法为本领域所公知，在此不再具体描述。
在第八方面，本申请提供了一种锂电池正极，包含正极材料、粘结剂和导电剂，其中所述正极材料为根据本申请的第四方面或第六方面所述的正极材料。
在本申请中，所述导电剂和粘结剂可以为本领域常规使用的各种导电剂、粘结剂，例如导电剂可以是乙炔黑、碳纳米管、石墨烯、导电高分子材料等，粘结剂可以是聚偏氟乙烯，聚四氟乙烯，聚乙烯醇等，本申请在此不再赘述。所述导电剂、粘结剂的用量也可以为本领域常规的用量，例如，以正极的总量为基准，所述正极材料的质量含量可以为约50-98％，所述导电剂的质量含量可以为约1-25％，所述粘结剂 的质量含量可以为约1-25％。
在本申请中，所述锂电池正极可以通过各种本领域公知的方法制备，本申请对此没有特别的限制，可以由本领域技术人员根据需要进行选择。例如，在某些具体施方式中，可以将正极材料、导电剂和粘结剂均匀混合、涂布和切片，得到锂电池正极。
在第九方面，本申请提供了一种锂电池，包含正极、负极、电解质和隔膜，其中所述正极为根据本申请第八方面所述的锂电池正极。
根据本申请，所述负极、电解质和隔膜可以使用常规用于锂电池中的那些材料，本申请对此没有严格的限制。例如，所述负极可以选自天然石墨、人造石墨、软碳、硬碳、中间相微球、硅、硅碳、锂等；所述电解质可以选自液态电解质、凝胶电解质、固态电解质等；所述隔膜可以选自聚乙烯隔膜、聚丙烯隔膜、聚乙烯/丙烯复合隔膜、聚酰亚胺隔膜等。
在某些优选实施方式中，本申请提供了如下的技术方案：
1、一种正极材料前驱体，其特征在于，所述正极材料前驱体包含片状单晶团聚物和多面体单晶颗粒；
其中，所述正极材料前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：I(001)/I(100)不低于1.5，I(001)/I(101)不低于1.2；
其中，所述正极材料前驱体的化学式为Ni xCo yM z(OH) 2，M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种；
其中，0.3≤x≤1，0≤y≤0.5，0≤z≤0.3。
2、一种正极材料前驱体的制备方法，其特征在于，该方法包括：
(1)间歇滴加金属盐溶液、沉淀剂溶液和可选的络合剂溶液进行混合并发生反应；
(2)将步骤(1)得到的产物进行固液分离和干燥处理，得到所述正极材料前驱体；
所述金属盐溶液含有金属元素Ni、Co和M，M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种；
其中，Ni元素、Co元素与M元素的摩尔用量比为(0.3-1)∶(0-0.5)∶(0-0.3)，其中Co和M的摩尔用量不为零。
3、根据项目2所述的制备方法，其中，所述金属盐溶液含有的金 属元素为Ni、Co和Mn的组合或Ni、Co和Al的组合；
优选地，所述金属盐溶液含有的金属盐选自金属硫酸盐、金属硝酸盐、金属醋酸盐和金属草酸盐中的至少一种；
优选地，以金属元素计，所述金属盐溶液的浓度为0.01-5mol/L。
4、根据项目2所述的制备方法，其中，沉淀剂选自NaOH、KOH和LiOH中的至少一种；
优选地，所述沉淀剂溶液的浓度为0.02-10mol/L。
5、根据项目2所述的制备方法，其中，所述络合剂选自铵离子供体、乙醇胺类络合剂、氨基羧酸类络合剂、羟氨基羧酸类络合剂和羧酸盐类络合剂的至少一种；
优选地，所述络合剂溶液的浓度为0.01-15mol/L。
6、根据项目2-5中任意一项所述的制备方法，其中，步骤(1)中，所述间歇滴加的过程包括：
(1)在反应条件下将所述金属盐溶液、所述沉淀剂溶液和所述可选的络合剂溶液同时滴加到反应釜中；
(2)上述三种溶液每次同时滴加2-12h后，停止金属盐溶液的进料0.5-4h；
(3)重复步骤(2)的间歇滴加过程，直至反应结束。
7、根据项目2或6所述的制备方法，其中，步骤(1)中，所述反应的条件包括：温度为30-70℃，优选为45-60℃；时间不低于10h，优选为24-72h；
优选地，所述混合在搅拌条件下进行；
更优选地，所述搅拌的速度为50-1000r/min。
8、项目1-7中任意一项所述的制备方法制得的正极材料前驱体。
9、一种正极材料，其特征在于，所述正极材料包含项目1或8所述的正极材料前驱体和锂元素；
优选地，以金属元素计，所述锂元素与所述正极材料前驱体的摩尔比为0.9-1.2∶1。
10、项目1或8所述的正极材料前驱体或项目9所述正极材料在锂电池中的应用。
11、一种正极材料，其特征在于，该正极材料的形貌为由一次单晶颗粒至少部分融合形成的二次单晶融合体；
其中，所述正极材料的化学式为LiNi xCo yM zO 2，M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种；
其中，0.3≤x≤1，0≤y≤0.5，0≤z≤0.3。
12、根据项目11所述的正极材料，其中，所述一次单晶颗粒的尺寸为0.2-3μm；和/或
所述二次单晶融合体的平均粒径为0.5-15μm。
13、一种正极材料的制备方法，其特征在于，该方法包括：
(1)将金属盐溶液、沉淀剂溶液和可选的络合剂溶液以间歇滴加的方式混合并反应，制备前驱体；
(2)将步骤(1)得到的所述前驱体和锂源混合后，通过固相反应制备所述正极材料；
所述金属盐溶液中的金属元素含有Ni、Co和M；
其中，M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种；
其中，Ni元素、Co元素与M元素的摩尔用量比为(0.3-1)∶(0-0.5)∶(0-0.3)，其中Co和M的摩尔用量不为零。
14、根据项目13所述的方法，其中，步骤(1)中，所述间歇滴加的方式包括所述间歇滴加的过程包括：
(1)在反应条件下将所述金属盐溶液、所述沉淀剂溶液和所述可选的络合剂溶液同时滴加到反应釜中；
(2)上述三种溶液每次同时滴加2-12h后，停止金属盐溶液的进料0.5-4h；
(3)重复步骤(2)的间歇滴加过程，直至反应结束。
15、根据项目13所述的方法，其中，步骤(1)中，所述反应条件包括：反应温度为30-70℃，反应时间不低于10h；
优选地，所述反应过程中在搅拌的条件下进行；
更优选地，所述搅拌的速率为50-1000rpm。
16、根据项目13所述的方法，其中，步骤(2)中，所述固相反应的方法包括对所述前驱体和所述锂源的混合物进行焙烧处理；
优选地，所述焙烧处理包括第一焙烧和第二焙烧；
更优选地，所述第一焙烧的条件包括：焙烧温度为300-600℃，焙 烧时间为1-10h；和/或
所述第二焙烧的条件包括：焙烧温度为650-1000℃，焙烧时间为4-48h。
17、根据项目13-16中任意一项所述的方法，其中，所述金属盐溶液中的金属元素为Ni、Co和Mn的组合或Ni、Co和Al的组合；
优选地，所述金属盐溶液中的金属盐选自金属硫酸盐、金属硝酸盐、金属醋酸盐和金属草酸盐中的至少一种；
优选地，以金属元素计，所述金属盐溶液的浓度为0.01-5mol/L。
18、根据项目13-16中任意一项所述的方法，其中，所述沉淀剂选自NaOH、KOH和LiOH中的至少一种；
优选地，所述沉淀剂溶液的浓度为0.02-10mol/L。
19、根据项目13-16中任意一项所述的方法，其中，所述络合剂选自铵离子供体、乙醇胺类络合剂、氨基羧酸类络合剂、羟氨基羧酸类络合剂和羧酸盐类络合剂中的至少一种；
优选地，所述络合剂溶液的浓度为0.01-15mol/L。
20、根据项目13-16中任意一项所述的方法，其中，所述锂源选自硝酸锂、氯化锂、碳酸锂、氢氧化锂和醋酸锂中的至少一种；
优选地，以金属元素计，所述锂源与所述前驱体的摩尔比为0.9-1.2∶1。
21、项目13-20中任意一项所述的方法制备得到的正极材料。
22、一种锂电池正极，其特征在于，包含正极材料、粘结剂和导电剂；
其中，所述正极材料为项目11、12或21任意一项所述的正极材料；
优选地，所述锂电池正极中，所述正极材料的含量为50-98重量％，所述粘结剂的含量为1-25重量％，所述导电剂的用量为1-25重量％。
23、项目11、12或21中任意一项所述的正极材料或项目22所述的锂电池正极在锂电池中的应用。
实施例
以下将通过实施例对本申请进行详细描述。
在本申请的各实施例和对比例中，扫描电子显微镜图(SEM)通过德国ZEISS公司ZEISS Merlin型号的扫描电子显微镜得到。
在本申请的各实施例和对比例中，X射线衍射(XRD)图谱通过 德国布鲁克公司D8 Advance SS型号的X射线衍射仪测得。
在本申请的各实施例和对比例中，透射电子显微镜图(TEM)通过美国赛默飞公司FEI Titan Cubed Themis G2 300型号的球差校正透射电子显微镜检测得到。该透射电子显微镜检测的制样流程如下：取少量粉末样品加入乙醇溶剂中，140W功率的超声分散15分钟后，吸取上层清液滴加到铜网上，烘干铜网上的溶剂后放入样品仓中进行观察。
在本申请的各实施例和对比例中，前躯体和正极材料的组成是通过美国安捷伦公司Varian 725 ES型号的电感耦合等离子体光谱仪(ICP-OES)测得。
在本申请的各实施例和对比例中，正极材料截面制样流程如下：将正极材料∶碳黑∶PVDF(粘结剂)按照90∶5∶5的质量比例混合均匀，涂布在铝箔上，80℃真空干燥6h得到含有正极材料的极片。之后使用洁净的刀片切割极片，并将切割的极片粘在样品台上，在三离子束截面模式下，使用5kV的加速电压处理极片2h得到平整干净的截面进行扫描电镜的观察。
以下实施例和对比例中，所用金属盐溶液均为硫酸盐溶液。
实施例1
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为8∶1∶1)浓度为2mol/L的金属盐溶液；配制浓度为4mol/L的NaOH溶液；配制浓度为6mol/L的氨水溶液。
将配制好的金属盐溶液、NaOH溶液和氨水溶液在搅拌状态下同时滴加到反应釜中发生沉淀反应。金属盐溶液的滴加速度为60mL/h；氨水溶液的滴加速度为60mL/h，通过控制NaOH溶液的滴加速度，使得反应体系的pH值为11。三种溶液同时滴加6h后，停止金属盐溶液的进料1h，保持NaOH和氨水溶液的进料，上述过程反复进行。
在所述反应过程中，控制搅拌速度为600rpm，反应温度为55℃，反应时间为48h。自然冷却后沉淀反应终止，将上述浆料进行真空抽滤，用去离子水洗涤3次后，在120℃真空干燥箱中烘干脱水12h，得到正 极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.799∶0.100∶0.101。所得正极材料前驱体的SEM图如图1A和图1B所示，从图中可看出，与传统多晶球形团聚体形貌明显不同，所述正极材料前驱体由片状单晶团聚体和多面体单晶颗粒组成。
所述正极材料前驱体的XRD图谱如图2所示，所述正极材料前驱体的衍射峰非常尖锐，表明所述正极材料前驱体的晶体结构发育良好，其中(001)和(101)晶面对应的衍射峰强度较高，特别是(001)晶面对应的衍射峰强度明显强于其它衍射峰强度，表明所述正极材料前驱体的(001)和(101)晶面，特别是(001)晶面，暴露更为充分，I(001)/I(100)的强度比为2.45，I(001)/I(101)的强度比为1.45，I(101)/I(100)的强度比为1.69。
(3)正极材料的制备
取上述正极材料前驱体10g，加入锂源LiOH·H 2O，使得Li∶(Ni+Co+Mn)的摩尔比为1.02∶1，将两者球磨2h混合均匀后装入坩埚进行高温分步焙烧，第一步：从室温以5℃/min升温至450℃，保温6h，第二步：从450℃以5℃/min升温至850℃，保温12h，之后自然冷却，得到正极材料。
(4)正极材料的评价
所述正极材料的SEM图如图3A和图3B所示，从图中可看出，所述正极材料的颗粒形貌为由一次单晶颗粒至少部分融合形成的二次单晶融合体。所述正极材料的一次单晶颗粒的平均尺寸为0.2-3μm；所述二次单晶融合体的平均粒径为0.5-15μm。所述正极材料的TEM图如图3C所示，从图3C中可以明显看出，在经过制样流程的超声分散处理之后，所述正极材料的颗粒形貌仍然保持为由一次单晶颗粒至少部分融合形成的融合体。所述正极材料的截面的SEM图如图3D所示，可以更加直观和明显的看到一次单晶颗粒彼此融合生长在一起形成了二次融合体颗粒。
所述正极材料的XRD图谱如图4所示，所述正极材料的衍射峰非常尖锐，表明所述正极材料的晶体结构发育良好；图谱上没有杂峰，说明所述正极材料具有较高的纯度。所述正极材料的XRD图谱中，在2θ角为18.6°、36.5°和44.3°附近分别具有特征衍射峰，其中，在2θ 角为18.6°附近的衍射峰的强度与2θ角为44.3°附近的衍射峰的强度的比值为1.8；并且在2θ角为65°附近的衍射峰分裂明显，表明所述正极材料形成了良好的层状晶体结构。
对正极材料进行电化学性能的评价：取上述正极材料10g，加入乙炔黑1.25g，12.5g质量分数为10％的聚偏氟乙烯溶液(溶剂为N-甲基吡咯烷酮)，混合均匀后，涂布、切片得到正极极片，负极采用锂片，电解质为液态电解质，该液态电解质由溶质、溶剂和添加剂组成，其中溶质为LiPF 6，浓度为1.2M，溶剂为体积比为1∶1∶1的EC∶DEC∶DMC的混合溶剂，添加剂为VC，浓度为1.5wt％，隔膜为市面购买的美国cellgard2325隔膜，将上述电池组件在手套箱中装成锂电池。测定该锂电池的电化学性能，所得0.1C倍率下的充放电曲线如图5所示，材料的充电比容量为224.6mAh/g，放电比容量为206.9mAh/g，首周效率可达92.1％。1C倍率下的循环稳定性曲线如图6所示，循环80圈后的容量保持率可达96.1％，循环稳定性优异。倍率性能结果如图7所示，即使在10C的高倍率条件下，材料的放电容量可以达到约120mAh/g。
所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例2
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为18∶1∶1)浓度为2mol/L的金属盐溶液；配制浓度为4mol/L的NaOH溶液；配制浓度为6mol/L的氨水溶液。
将配制好的金属盐溶液、NaOH溶液和氨水溶液在搅拌状态下同时滴加到反应釜中发生沉淀反应。金属盐溶液的滴加速度为60mL/h；氨水溶液的滴加速度为60mL/h，通过控制NaOH溶液的滴加速度，使得反应体系的pH值为11。三种溶液同时滴加6h后，停止金属盐溶液的进料1h，保持NaOH和氨水溶液的进料，上述过程反复进行。
在所述反应过程中，控制搅拌速度为600rpm，反应温度为55℃，反应时间为48h。自然冷却后沉淀反应终止，将上述浆料进行真空抽滤，用去离子水洗涤3次后，在120℃真空干燥箱中烘干脱水12h，得到正 极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.903∶0.048∶0.049。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.37，I(001)/I(101)的强度比为1.48，I(101)/I(100)的强度比为1.60。
(3)正极材料的制备
取上述正极材料前驱体10g，加入锂源LiOH·H 2O，使得Li∶(Ni+Co+Mn)的摩尔比为1.02∶1，将两者球磨2h混合均匀后装入坩埚进行高温分步焙烧，第一步：从室温以10℃/min升温至500℃，保温4h，第二步：从500℃以10℃/min升温至750℃，保温8h，之后自然冷却，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例3
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为3∶1∶1)浓度为2mol/L的金属盐溶液；配制浓度为4mol/L的NaOH溶液；配制浓度为6mol/L的氨水溶液。
将配制好的金属盐溶液、NaOH溶液和氨水溶液在搅拌状态下同时滴加到反应釜中发生沉淀反应。金属盐溶液的滴加速度为60mL/h；氨水溶液的滴加速度为60mL/h，通过控制NaOH溶液的滴加速度，使得反应体系的pH值为11。三种溶液同时滴加6h后，停止金属盐溶液的进料1h，保持NaOH和氨水溶液的进料，上述过程反复进行。
在所述反应过程中，控制搅拌速度为600rpm，反应温度为55℃，反应时间为48h。自然冷却后沉淀反应终止，将上述浆料进行真空抽滤，用去离子水洗涤3次后，在120℃真空干燥箱中烘干脱水12h，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.602∶0.201∶0.197。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.59，I(001)/I(101)的强度比为1.22，I(101)/I(100)的强度比为1.30。
(3)正极材料的制备
取上述前驱体10g，加入锂源LiOH·H 2O，使得Li∶(Ni+Co+Mn)的摩尔比为1.02∶1，将两者球磨2h混合均匀后装入坩埚进行高温分步焙烧，第一步：从室温以3℃/min升温至550℃，保温8h，第二步：从550℃以3℃/min升温至900℃，保温24h，之后自然冷却，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例4
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为8∶1∶1)浓度为3mol/L的金属盐溶液；配制浓度为8mol/L的NaOH溶液；配制浓度为10mol/L的氨水溶液。
按照实施例1所述的方法进行操作，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.797∶0.098∶0.105。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.98，I(001)/I(101)的强度比为1.42，I(101)/I(100)的强度比为1.39。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例5
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为8∶1∶1)浓度为0.5mol/L的金属盐溶液；配制浓度为2mol/L的NaOH溶液；配制浓度为2mol/L的氨水溶液。
按照实施例1所述的方法进行操作，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.802∶0.101∶0.097。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.87，I(001)/I(101)的强度比为1.39，I(101)/I(100)的强度比为1.35。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例6
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为8∶1∶1)浓度为5mol/L的金属盐溶液；配制浓度为10mol/L的NaOH溶液；配制浓度为15mol/L的氨水溶液。
按照实施例1所述的方法进行操作，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.801∶0.099∶0.100。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似， 其中I(001)/I(100)的强度比为1.77，I(001)/I(101)的强度比为1.33，I(101)/I(100)的强度比为1.33。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例7
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
配制金属离子(其中，镍钴锰元素的摩尔比为8∶1∶1)浓度为0.01mol/L的金属盐溶液；配制浓度为0.02mol/L的NaOH溶液；配制浓度为0.01mol/L的氨水溶液。
按照实施例1所述的方法进行操作，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.799∶0.103∶0.098。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.71，I(001)/I(101)的强度比为1.29，I(101)/I(100)的强度比为1.33。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例8
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是，所述滴加过程中通 过调节NaOH溶液的滴加速率，控制体系的pH值为12，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.797∶0.102∶0.101。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.65，I(001)/I(101)的强度比为1.25，I(101)/I(100)的强度比为1.32。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例9
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是，所述滴加过程中通过调节NaOH溶液的滴加速率，控制体系的pH值为9，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.791∶0.105∶0.104。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.68，I(001)/I(101)的强度比为1.26，I(101)/I(100)的强度比为1.33。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例10
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是，所述滴加过程中控制反应温度为70℃，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.800∶0.098∶0.102。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.86，I(001)/I(101)的强度比为1.38，I(101)/I(100)的强度比为1.35。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例11
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是，所述滴加过程中控制反应温度为30℃，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.805∶0.102∶0.093。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.02，I(001)/I(101)的强度比为1.44，I(101)/I(100)的强度比为1.40。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得 放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例12
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是反应时间为12h，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.792∶0.104∶0.104。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.81，I(001)/I(101)的强度比为1.38，I(101)/I(100)的强度比为1.31。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例13
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是搅拌速度为50r/min，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.789∶0.108∶0.103。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为1.62，I(001)/I(101)的强度比为1.24，I(101)/I(100)的强度比为1.31。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例14
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是搅拌速度为1000r/min，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.800∶0.100∶0.100。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.41，I(001)/I(101)的强度比为1.51，I(101)/I(100)的强度比为1.60。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例15
本实施例用于说明本申请所述的正极材料的制备和评价方法
(1)正极材料的制备
按照实施例1所述的方法制备正极材料，不同的是，分步焙烧的第一步：从室温以5℃/min升温至600℃，保温1h，第二步：从600℃以5℃/min升温至750℃，保温48h，得到正极材料。
(2)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例16
本实施例用于说明本申请所述的正极材料的制备和评价方法
(1)正极材料的制备
按照实施例1所述的方法制备正极材料，不同的是，分步焙烧的第一步：从室温以5℃/min升温至300℃，保温10h，第二步：从300℃以5℃/min升温至1000℃，保温4h，得到正极材料。
(2)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例17
本实施例用于说明本申请所述的正极材料的制备和评价方法
(1)正极材料的制备
按照实施例1所述的方法制备正极材料，不同的是，采用一步焙烧，从室温以5℃/min升温至850℃，保温12h，得到正极材料。
(2)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例18
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是沉淀剂使用的是同样浓度的KOH溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.799∶0.101∶0.100。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.43，I(001)/I(101)的强度比为1.51，I(101)/I(100)的强度比为1.61。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例19
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是络合剂使用的是同样浓度的二乙醇胺溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.792∶0.105∶0.103。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.42，I(001)/I(101)的强度比为1.58，I(101)/I(100)的强度比为1.53。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例20
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是络合剂使用的是同样浓度的乙二胺四乙酸二钠溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.805∶0.097∶0.098。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.43，I(001)/I(101)的强度比为1.55，I(101)/I(100)的强度比为1.57。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例21
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是络合剂使用的是同样浓度的柠檬酸钠溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.800∶0.102∶0.098。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.43，I(001)/I(101)的强度比为1.54，I(101)/I(100)的强度比为1.58。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例22
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐是2mol/L的镍钴铝元素摩尔比为8∶1.5∶0.5的溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Al的摩尔比为0.802∶0.153∶0.045。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.44，I(001)/I(101)的强度比为1.53，I(101)/I(100)的强度比为1.59。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例23
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐是2mol/L的镍钴镁元素摩尔比为8∶1∶1的溶液，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mg的摩尔比为0.801∶0.102∶0.097。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.44，I(001)/I(101)的强度比为1.55，I(101)/I(100)的强度比为1.57。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例24
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐溶液中额外加入0.02mol/L的TiSO 4，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn∶Ti的摩尔比为0.795∶0.101∶0.104∶0.009。正极材料前驱体的SEM图与图1A和图1B相 似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.32，I(001)/I(101)的强度比为1.49，I(101)/I(100)的强度比为1.56。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例25
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐溶液中额外加入0.01mol/L的Cr 2(SO 4) 3，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn∶Cr的摩尔比为0.798∶0.103∶0.099∶0.011。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.29，I(001)/I(101)的强度比为1.47，I(101)/I(100)的强度比为1.56。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例26
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐溶液额外中加入0.02mol/L的Fe(NO 3) 3·9H 2O，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn∶Fe的摩尔比为0.803∶0.096∶0.101∶0.010。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.26，I(001)/I(101)的强度比为1.47，I(101)/I(100)的强度比为1.54。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例27
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐溶液中额外加入0.02mol/L的CuSO 4·5H 2O，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn∶Cu的摩尔比为0.801∶0.100∶0.099∶0.009。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.09，I(001)/I(101)的强度比为1.45，I(101)/I(100)的强度比为1.44。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
实施例28
本实施例用于说明本申请所述的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1所述的方法进行操作，不同的是金属盐溶液中额外加 入0.02mol/L的ZnSO 4·H 2O，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn∶Zn的摩尔比为0.797∶0.104∶0.099∶0.010。正极材料前驱体的SEM图与图1A和图1B相似，XRD图与图2相似，其中I(001)/I(100)的强度比为2.13，I(001)/I(101)的强度比为1.46，I(101)/I(100)的强度比为1.46。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图与图3A和图3B相似，TEM图与图3C相似。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3。
对比例1
本对比例用于说明非本申请的正极材料前驱体、正极材料的制备和评价方法
(1)正极材料前驱体的制备
按照实施例1的方法进行操作，不同的是，所述滴加过程为金属溶液、沉淀剂溶液和络合剂溶液的连续滴加，没有金属溶液的间歇滴加过程，得到正极材料前驱体。
(2)正极材料前驱体的评价
所得正极材料前驱体中Ni∶Co∶Mn的摩尔比为0.799∶0.102∶0.099。所得正极材料前驱体的SEM图如图8所示，可看出所述正极材料前驱体的形貌特征为多晶球形团聚体，球形度较好。
XRD图如图9所示，可看出，其(001)晶面、(100)晶面和(101)晶面之间的差异较小，I(001)/I(100)的强度比为1.19，I(001)/I(101)的强度比为1.04，I(101)/I(100)的强度比为1.14。
(3)正极材料的制备
按照实施例1所述的方法进行操作，得到正极材料。
(4)正极材料的评价
正极材料的SEM图如图10A所示，可看出所得到的正极材料的形貌特征为由纳米级或亚微米级一次颗粒组成的二次微米多晶球形团聚体，球形度较好。
所述正极材料的TEM图如图10B所示，其中从图10B中可以明显看出，在经过制样流程的超声处理之后，所述正极材料的二次微米多晶球形团聚体部分崩解，产生离散的个体纳米颗粒。
按照实施例1所述的方法对正极材料进行电化学性能的评价，所得放电容量、首周效率和循环80圈后的容量保持率的具体结果见表3，倍率性能结果如图11所示。
表1实施例1-28和对比例1的正极材料前驱体和正极材料的金属元素组成
编号 正极材料前驱体 正极材料
实施例1 Ni 0.799Co 0.100Mn 0.101 Li 1.010Ni 0.799Co 0.100Mn 0.101
实施例2 Ni 0.903Co 0.048Mn 0.049 Li 1.011Ni 0.903Co 0.048Mn 0.049
实施例3 Ni 0.602Co 0.201Mn 0.197 Li 1.005Ni 0.602Co 0.201Mn 0.197
实施例4 Ni 0.797Co 0.098Mn 0.105 Li 1.007Ni 0.797Co 0.098Mn 0.105
实施例5 Ni 0.802Co 0.101Mn 0.097 Li 1.008Ni 0.802Co 0.101Mn 0.097
实施例6 Ni 0.801Co 0.099Mn 0.100 Li 1.006Ni 0.801Co 0.099Mn 0.100
实施例7 Ni 0.799Co 0.103Mn 0.098 Li 1.011Ni 0.799Co 0.103Mn 0.098
实施例8 Ni 0.797Co 0.102Mn 0.101 Li 1.009Ni 0.797Co 0.102Mn 0.101
实施例9 Ni 0.791Co 0.105Mn 0.104 Li 1.002Ni 0.791Co 0.105Mn 0.104
实施例10 Ni 0.800Co 0.098Mn 0.102 Li 1.008Ni 0.800Co 0.098Mn 0.102
实施例11 Ni 0.805Co 0.102Mn 0.093 Li 1.005Ni 0.805Co 0.102Mn 0.093
实施例12 Ni 0.792Co 0.104Mn 0.104 Li 1.004Ni 0.792Co 0.104Mn 0.104
实施例13 Ni 0.789Co 0.108Mn 0.103 Li 1.003Ni 0.789Co 0.108Mn 0.103
实施例14 Ni 0.800Co 0.100Mn 0.100 Li 1.010Ni 0.800Co 0.100Mn 0.100
实施例15 Ni 0.799Co 0.100Mn 0.101 Li 1.013Ni 0.799Co 0.100Mn 0.101
实施例16 Ni 0.799Co 0.100Mn 0.101 Li 0.997Ni 0.799Co 0.100Mn 0.101
实施例17 Ni 0.799Co 0.100Mn 0.101 Li 1.016Ni 0.799Co 0.100Mn 0.101
实施例18 Ni 0.799Co 0.101Mn 0.100 Li 1.007Ni 0.799Co 0.101Mn 0.100
实施例19 Ni 0.792Co 0.105Mn 0.103 Li 1.003Ni 0.792Co 0.105Mn 0.103
实施例20 Ni 0.805Co 0.097Mn 0.098 Li 1.005Ni 0.805Co 0.097Mn 0.098
实施例21 Ni 0.800Co 0.102Mn 0.098 Li 1.004Ni 0.800Co 0.102Mn 0.098
实施例22 Ni 0.802Co 0.153Al 0.045 Li 1.007Ni 0.802Co 0.153Al 0.045
实施例23 Ni 0.801Co 0.102Mg 0.097 Li 1.008Ni 0.801Co 0.102Mg 0.097
实施例24 Ni 0.795Co 0.101Mn 0.104Ti 0.009 Li 1.005Ni 0.795Co 0.101Mn 0.104Ti 0.009
实施例25 Ni 0.798Co 0.103Mn 0.099Cr 0.011 Li 1.015Ni 0.798Co 0.103Mn 0.099Cr 0.011
实施例26 Ni 0.803Co 0.096Mn 0.101Fe 0.010 Li 1.007Ni 0.803Co 0.096Mn 0.101Fe 0.010
实施例27 Ni 0.801Co 0.100Mn 0.099Cu 0.009 Li 1.005Ni 0.801Co 0.100Mn 0.099Cu 0.009
实施例28 Ni 0.797Co 0.104Mn 0.099Zn 0.010 Li 1.008Ni 0.797Co 0.104Mn 0.099Zn 0.010
对比例1 Ni 0.799Co 0.102Mn 0.099 Li 1.010Ni 0.799Co 0.102Mn 0.099
表2实施例1-28和对比例1的衍射峰强度的比例关系
编号 I(001)/I(100) I(001)/I(101) I(101)/I(100)
实施例1 2.45 1.45 1.69
实施例2 2.37 1.48 1.60
实施例3 1.59 1.22 1.30
实施例4 1.98 1.42 1.39
实施例5 1.87 1.39 1.35
实施例6 1.77 1.33 1.33
实施例7 1.71 1.29 1.33
实施例8 1.65 1.25 1.32
实施例9 1.68 1.26 1.33
实施例10 1.86 1.38 1.35
实施例11 2.02 1.44 1.40
实施例12 1.81 1.38 1.31
实施例13 1.62 1.24 1.31
实施例14 2.41 1.51 1.60
实施例15 2.45 1.45 1.69
实施例16 2.45 1.45 1.69
实施例17 2.45 1.45 1.69
实施例18 2.43 1.51 1.61
实施例19 2.42 1.58 1.53
实施例20 2.43 1.55 1.57
实施例21 2.43 1.54 1.58
实施例22 2.44 1.53 1.59
实施例23 2.44 1.55 1.57
实施例24 2.32 1.49 1.56
实施例25 2.29 1.47 1.56
实施例26 2.26 1.47 1.54
实施例27 2.09 1.45 1.44
实施例28 2.13 1.46 1.46
对比例1 1.19 1.04 1.14
表3实施例1-28和对比例1的实验结果
编号 放电容量mAh/g 首周效率％ 容量保持率％
实施例1 206.9 92.1 96.1
实施例2 204.7 91.4 95.1
实施例3 181.5 91.9 95.7
实施例4 201.5 91.2 94.9
实施例5 200.4 91.1 94.6
实施例6 199.3 90.9 94.1
实施例7 198.8 90.5 93.9
实施例8 197.9 90.3 93.1
实施例9 198.4 91.5 94.3
实施例10 200.1 91.2 94.2
实施例11 201.7 91.0 93.5
实施例12 199.5 90.7 92.8
实施例13 195.4 90.4 91.9
实施例14 205.1 92.0 95.9
实施例15 202.7 91.6 95.1
实施例16 203.1 91.5 95.7
实施例17 203.8 91.3 94.5
实施例18 206.8 92 95.8
实施例19 205.4 91.6 95.2
实施例20 205.8 91.7 95.6
实施例21 206.1 91.9 95.8
实施例22 206.7 92 96.0
实施例23 206.4 91.9 95.9
实施例24 203.8 91.7 95.9
实施例25 203.5 92 95.4
实施例26 203.4 91.8 95.3
实施例27 202.4 91.4 95.9
实施例28 202.9 91.8 96
对比例1 184.7 86.6 88.1
从表3所示结果的比较可以看出，与对比例相比，本申请的锂电池正极材料前驱体区别于具有多晶球形团聚体形貌的前驱体，含有片状单晶团聚体和多面体单晶颗粒，其(001)晶面和(101)晶面的暴露面积更多；同时，本申请的锂电池正极材料区别于多晶球形团聚体材料和分散型单晶颗粒材料，是由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒材料，具有更好的电化学性能，比如更高的放电容量和首周效率，且循环性能也得到了提高。
从图7和图11所示的倍率性能结果的比较可以看出，与对比例相比，本申请的锂电池正极材料前驱体和正极材料的倍率性能明显更好，在高倍率下放电容量明显更高，比如在10C的倍率下，使用本申请的前躯体材料得到的正极材料的放电容量是对比例得到的正极材料的约2倍。
以上详细描述了本申请的优选实施方式，但是，本申请并不限于此。在本申请的技术构思范围内，可以对本申请的技术方案进行多种简单变型，包括各个技术特征以任何其它的合适方式进行组合，这些简单变型和组合同样应当视为本申请所公开的内容，均属于本申请的保护范围。

Claims (21)

  1. 一种锂电池正极材料前驱体，所述前驱体具有化学式Ni xCo yM z(OH) 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且x、y和z的取值满足电中性规则，
    其中，所述前驱体包含片状单晶团聚体和多面体单晶颗粒，并且所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：
    I(001)/I(100)不低于约1.5，且
    I(001)/I(101)不低于约1.2，
    优选地，I(101)/I(100)不低于约1.3，
    其中I(001)、I(100)和I(101)分别表示以衍射峰高度计的(001)晶面、(100)晶面和(101)晶面的衍射峰强度。
  2. 根据权利要求1所述的前驱体，其中M为Mn、Al和Mg中的至少一种，或者为Mn、Al和Mg中的至少一种与选自Fe、Cr、Cu、Ti、W、Mo、Nb、Zn、Sn、Zr和Ga中的至少一者的组合。
  3. 根据权利要求1所述的前驱体，其中0.6≤x≤0.95，0.025≤y≤0.2，0.025≤z≤0.2。
  4. 根据权利要求1所述的前驱体，其中所述前驱体的XRD图谱中，I(001)、I(100)和I(101)之间满足以下关系：
    I(001)/I(100)不低于约1.8，优选不高于约10；
    I(001)/I(101)不低于约1.3，优选不高于约5；且
    I(101)/I(100)不低于约1.5，优选不高于约5。
  5. 一种锂电池正极材料前驱体的制备方法，包括如下步骤：
    (1)将金属盐溶液与沉淀剂溶液和络合剂溶液混合进行反应，其中所述沉淀剂溶液和络合剂溶液以连续方式进料到反应体系中，而所述金属盐溶液以间歇方式进料到反应体系中；
    (2)将步骤(1)得到的产物进行固液分离和干燥处理，得到所述前驱体；
    其中，所述金属盐溶液中的金属包括Ni、Co和M，所述金属M选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种，
    金属Ni、Co与M的摩尔用量比为约(0.3-1)∶(0-0.5)∶(0-0.3)，其中Co和M的摩尔用量不为零，优选为约(0.6-0.95)∶(0.025-0.2)∶(0.025-0.2)。
  6. 根据权利要求5所述的方法，其中，所述金属M为Mn、Al和Mg中的至少一种，或者为Mn、Al和Mg中的至少一种与选自Fe、Cr、Cu、Ti、W、Mo、Nb、Zn、Sn、Zr和Ga中的至少一者的组合；
    优选地，所述金属盐选自硫酸盐、硝酸盐、醋酸盐、氯化物和草酸盐中的至少一种；
    优选地，以金属元素计，所述金属盐溶液的浓度为约0.01-5mol/L，优选约0.5-3mol/L，更优选约1-2mol/L。
  7. 根据权利要求5或6所述的方法，其中，所述沉淀剂选自NaOH、KOH和LiOH中的至少一种；
    优选地，所述沉淀剂溶液的浓度为约0.02-10mol/L，优选约2-8mol/L，更优选约2-6mol/L。
  8. 根据权利要求5-7中任一项所述的方法，其中，所述络合剂选自铵离子供体、乙醇胺类络合剂、氨基羧酸类络合剂、羟氨基羧酸类络合剂和羧酸盐类络合剂的至少一种；
    优选地，所述络合剂溶液的浓度为约0.01-15mol/L，优选约2-10mol/L，更优选约2-6mol/L。
  9. 根据权利要求5-8中任一项所述的方法，其中，步骤(1)的反应条件包括：温度为约30-70℃，优选为约45-60℃；时间不低于约10h，优选为约24-72h，pH为约9-14，优选为约9-12，并且所述金属盐溶液至少分两次进料到所述反应体系中；
    优选地，步骤(1)的所述混合在搅拌条件下进行，所述搅拌的速度优选为约50-1000r/min。
  10. 根据权利要求5-9中任一项所述的方法，其中，所述步骤(1)进一步包括：
    (1a)将所述金属盐溶液、所述沉淀剂溶液和所述络合剂溶液连续进料到反应器中，使它们混合并发生反应，持续约2-12h；
    (1b)暂停所述金属盐溶液的进料约0.5-4h；
    (1c)重复步骤(1a)-(1b)，直至反应结束。
  11. 一种锂电池正极材料，所述正极材料具有化学式 Li aNi xCo yM zO 2，M为选自Fe、Cr、Cu、Ti、Mg、W、Mo、Nb、Zn、Sn、Zr、Ga、Mn和Al中的至少一种金属，其中，0.9≤a≤1.2，0.3≤x≤1，0＜y≤0.5，0＜z≤0.3，且a、x、y和z的取值满足电中性规则；
    其中，所述正极材料包含由一次单晶颗粒至少部分融合形成的二次单晶融合体形式的颗粒。
  12. 根据权利要求11所述的正极材料，具有以下特征中的一个或多个：
    所述一次单晶颗粒的平均尺寸为约0.2-3μm；
    所述二次单晶融合体的平均粒径为约0.5-15μm；以及
    所述正极材料具有层状晶体结构。
  13. 根据权利要求11或12所述的正极材料，其中M为Mn、Al和Mg中的至少一种，或者为Mn、Al和Mg中的至少一种与选自Fe、Cr、Cu、Ti、W、Mo、Nb、Zn、Sn、Zr和Ga中的至少一者的组合。
  14. 根据权利要求11-13中任一项所述的正极材料，其中0.6≤x≤0.95，0.025≤y≤0.2，0.025≤z≤0.2。
  15. 根据权利要求11-14中任一项所述的正极材料，其中所述正极材料通过根据权利要求1-4中任一项所述的锂电池正极材料前驱体与锂源的固相反应得到。
  16. 一种锂电池正极材料的制备方法，包括如下步骤：
    (I)提供锂电池正极材料的前驱体；
    (II)将所述前驱体和锂源混合进行固相反应，得到所述正极材料；
    其中所述前驱体为根据权利要求1-4中任一项所述的锂电池正极材料前驱体。
  17. 根据权利要求16所述的方法，其中，所述步骤(I)进一步包括按照权利要求5-10中任一项所述的方法制备所述锂电池正极材料的前驱体。
  18. 根据权利要求16或17所述的方法，其中，在步骤(II)中，所述固相反应通过对所述前驱体和所述锂源的混合物进行焙烧处理来进行；
    优选地，所述焙烧处理包括第一焙烧和第二焙烧，其中：
    所述第一焙烧的条件包括：焙烧温度为约300-600℃，焙烧时间为约1-10h；和
    所述第二焙烧的条件包括：焙烧温度为约650-1000℃，焙烧时间为约4-48h。
  19. 根据权利要求16-18中任一项所述的方法，其中，所述锂源选自硝酸锂、氯化锂、碳酸锂、氢氧化锂和醋酸锂中的至少一种；
    优选地，以金属元素计，所述锂源与所述前驱体的摩尔比为约0.9-1.2∶1。
  20. 一种锂电池正极，包含正极材料、粘结剂和导电剂，其中所述正极材料为根据权利要求11-15中任一项所述的锂电池正极材料；
    优选地，所述锂电池正极中，所述正极材料的含量为约50-98重量％，所述粘结剂的含量为约1-25重量％，所述导电剂的含量为约1-25重量％。
  21. 一种锂电池，包含正极、负极、电解质和隔膜，其中所述正极为根据权利要求20所述的锂电池正极。
PCT/CN2020/121341 2019-10-17 2020-10-16 锂电池正极材料前驱体、其制备方法及应用 WO2021073583A1 (zh)

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