WO2020063680A1 - 正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置 - Google Patents

正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置 Download PDF

Info

Publication number
WO2020063680A1
WO2020063680A1 PCT/CN2019/107909 CN2019107909W WO2020063680A1 WO 2020063680 A1 WO2020063680 A1 WO 2020063680A1 CN 2019107909 W CN2019107909 W CN 2019107909W WO 2020063680 A1 WO2020063680 A1 WO 2020063680A1
Authority
WO
WIPO (PCT)
Prior art keywords
positive electrode
active material
electrode active
mass
ppm
Prior art date
Application number
PCT/CN2019/107909
Other languages
English (en)
French (fr)
Inventor
吴奇
何金华
吉长印
Original Assignee
宁德时代新能源科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宁德时代新能源科技股份有限公司 filed Critical 宁德时代新能源科技股份有限公司
Priority to EP19867335.2A priority Critical patent/EP3817102B1/en
Publication of WO2020063680A1 publication Critical patent/WO2020063680A1/zh
Priority to US17/131,012 priority patent/US11527752B2/en

Links

Images

Classifications

    • 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
    • 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
    • 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
    • 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
    • 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
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • 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
    • H01M4/485—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy
    • 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
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • 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
    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/50—Solid solutions
    • C01P2002/52—Solid solutions containing elements as dopants
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—Particles characterised by their size
    • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
    • C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
    • C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other
    • 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
    • H01M2220/00—Batteries for particular applications
    • H01M2220/20—Batteries in motive systems, e.g. vehicle, ship, plane
    • 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

  • the present application relates to a positive electrode active material and a preparation method thereof, an electrochemical cell, a battery module, a battery pack, and a device.
  • Chinese patent application CN106058230A discloses a method for preparing a high nickel positive electrode material co-modified with aluminum doping and surface modification, which comprises mixing a high nickel positive electrode material precursor with an aluminum salt sol. Then, the powder is evaporated to dryness, and the powder is mixed and sintered with the lithium salt to obtain a high nickel positive electrode material.
  • the advantage of this method is that the uniformity of the mixing of the high nickel positive electrode material precursor and the aluminum salt is improved by wet coating, but Subsequent evaporation to dry energy consumption is high, and the lithium content of the impurity in the high nickel cathode material cannot be reduced well by this method, which is not conducive to improving the anti-flatulence performance of the battery.
  • Chinese patent application CN107611384A discloses a high-performance concentration-gradient high-nickel material, its preparation method, and its use in lithium-ion batteries. This method first prepares a nickel content that gradually increases from the outside to the inside.
  • the high-nickel precursor is sintered with a lithium salt to obtain a high-nickel positive electrode material.
  • the high-nickel positive electrode material has a higher tap density, but it does not improve the high-temperature cycling and flatulence performance issues that the high-nickel positive electrode material is most concerned about.
  • Chinese patent application CN106602021A with a filing date of December 22, 2016 discloses a coated lithium ion battery cathode material and a preparation method thereof.
  • the method is to dissolve a metal salt in deionized water, and then add the cathode material to stir, Drying and calcining to provide a coated lithium ion battery cathode material that can form a uniform coating layer on the surface of a high nickel cathode material and a method for preparing the same.
  • the synthesized material has a low content of heterolithium, but its cycle performance is average. 50 After two cycles, the capacity drops from about 190mAh / g to about 140mAh / g, and the capacity decays faster.
  • the object of the present application is to provide a positive electrode active material and a method for preparing the same, an electrochemical cell, a battery module, a battery pack, and a device.
  • the positive electrode active material has a high gram capacity and high structural stability As well as the characteristics of high thermal stability, the electrochemical cell can have excellent cycle performance and storage performance while having a high initial discharge gram capacity.
  • the present application provides a positive electrode active material, which includes a core and a covering layer, and the covering layer covers a surface of the core.
  • the core is selected from formula Li 1 + a [Ni x Co y Mn z M b M 'c] O 2-d Y d of the ternary material
  • the doping element M is selected from Zr, Ti, Te, Ca, Si One or more of them
  • the doping element M ′ is selected from one or more of Mg, Zn, Al, B, Ce, Fe
  • the doping element Y is selected from one or more of F, Cl, Br
  • the coating material is an oxide of a coating element M ′′, and the coating element M ′′ is selected from one or more of Mg, Zn, Al, B, Ce, and Fe.
  • the mass ratio of the cladding element M ′′ in the cladding layer to the doping element M ′ in the inner core is 1: (1 to 5).
  • the present application provides a method for preparing a positive electrode active material for preparing the positive electrode active material described in the first aspect of the present application, which includes the steps of: (1) converting a nickel-cobalt-manganese ternary material The precursor, the Li-containing compound, the M-containing compound, the M′-containing compound, and the Y-containing compound are placed in a mixing device for mixing, and then placed in an atmosphere furnace for one sintering; (2) the step (1) is completed once The resulting material was washed in a washing solution, then centrifuged and vacuum dried to obtain the core of the positive electrode active material, that is, the molecular formula is Li 1 + a [Ni x Co y Mn z M b M ′ c ] O 2-d Y d Ternary materials; (3) Put the core of the positive electrode active material and the M ′′ -containing compound in a mixing device for mixing, and then place it in an atmosphere furnace for secondary sintering to form
  • the present application provides an electrochemical cell including the positive electrode active material described in the first aspect of the present application.
  • the present application provides a battery module including the electrochemical cell described in the third aspect of the present application.
  • the present application provides a battery pack including the battery module described in the fourth aspect of the present application.
  • the present application provides a device including the electrochemical cell described in the third aspect of the present application, which is used as a power source of the device.
  • the positive electrode active material of the present application includes a core and a coating layer covering the surface of the core.
  • the elements M, M ′, and Y in the core that bulk-doped the ternary material satisfy the element distribution from the core to the outside of the core.
  • the core center has a reduced mass concentration gradient
  • the cladding layer includes M ′′ oxide
  • the mass ratio of the cladding element M ′′ in the cladding layer to the doping element M ′ in the core is 1: (1 to 5 )
  • Can make the positive electrode active material have the characteristics of high gram capacity, high structural stability and high thermal stability, so that the electrochemical cell has a high initial discharge gram capacity while having excellent cycle performance and storage performance.
  • the battery module, the battery pack and the device of the present application include the electrochemical cell, and thus have at least the same advantages as the electrochemical cell.
  • FIG. 1 is a perspective view of an embodiment of an electrochemical cell.
  • FIG. 2 is an exploded view of FIG. 1.
  • FIG. 3 is a schematic diagram of an embodiment of an electrode assembly of the electrochemical cell of FIG. 2, in which a first electrode sheet, a second electrode sheet, and a separator are wound to form a wound electrode assembly.
  • FIG. 4 is a schematic diagram of another embodiment of the electrode assembly of the electrochemical cell of FIG. 2, in which a first electrode sheet, a second electrode sheet, and a separator are laminated in a thickness direction to form a laminated electrode assembly.
  • FIG. 5 is a perspective view of an embodiment of a battery module.
  • FIG. 6 is a perspective view of an embodiment of a battery pack.
  • FIG. 7 is an exploded view of FIG. 6.
  • FIG. 8 is a schematic diagram of an embodiment of a device using an electrochemical cell as a power source.
  • the positive electrode active material and its preparation method, electrochemical cell, battery module, battery pack and device according to the present application will be described in detail below.
  • a positive active material which includes a core and a covering layer, the covering layer covering a surface of the core.
  • the core is selected from formula Li 1 + a [Ni x Co y Mn z M b M 'c] O 2-d Y d of the ternary material
  • the doping element M is selected from Zr, Ti, Te, Ca, Si One or more of them
  • the doping element M ′ is selected from one or more of Mg, Zn, Al, B, Ce, Fe
  • the doping element Y is selected from one or more of F, Cl, Br
  • the coating material is an oxide of a coating element M ′′, and the coating element M ′′ is selected from one or more of Mg, Zn, Al, B, Ce, and Fe.
  • the mass ratio of the cladding element M ′′ in the cladding layer to the doping element M ′ in the inner core is 1: (1 to 5).
  • Ni, Co, and Mn are transition metal elements adjacent to the same period. With the change of their proportions, the physical and chemical properties of the ternary materials will change. It is generally believed that Ni is one of the main active metal components in ternary materials, and mainly exists in the form of +2 valence. Ni 2+ will be oxidized to Ni 3+ , Ni 4+ , Co in the process of deintercalating lithium. It is also one of the active metal components, and mainly exists in the form of +3 valence.
  • the ternary material mainly achieves charge balance through the valence changes of Ni and Co.
  • Ni 2+ and Li + tend to occur. Mixed. The reason is that the radius of Ni 2+ is similar to that of Li + . In the process of lithium deintercalation, Ni 2+ is more likely to migrate to the vacancies formed by Li + deintercalation, which causes Li to precipitate.
  • Ni The proportion of 2+ mixed with Li + is continuously increasing, and the layered structure of the ternary material may collapse, which makes it more and more difficult to deintercalate Li + in the layered structure of the ternary material, eventually leading to the cycling performance of the electrochemical cell deterioration.
  • the increase in the Ni content in the ternary material will also reduce the thermal decomposition temperature of the ternary material, leading to an increase in the amount of heat release and a deterioration in the thermal stability of the ternary material.
  • the content of strongly oxidizing Ni 4+ also increases.
  • the electrolyte When the electrolyte contacts the ternary material, the electrolyte will have more side reactions with the ternary material, and In order to maintain the charge balance, the ternary material will release oxygen, which will not only destroy the crystal structure of the ternary material, but also accelerate the flatulence of the electrochemical cell and deteriorate the storage performance of the electrochemical cell.
  • Co can effectively stabilize the layered structure of the ternary material and suppress lithium-nickel mixed discharge, improve the electronic conductivity of the ternary material and improve the cycling performance of the electrochemical cell, but the cost of Co is higher.
  • the presence of Mn can improve the structural stability and safety performance of the ternary material, and can reduce the cost of the ternary material. However, if the content of Mn is too high, a spinel phase will appear and destroy the layered structure of the ternary material. The gram capacity of the material is reduced and at the same time the cycle performance of the electrochemical cell is deteriorated.
  • the relative content of Ni can be increased while the relative contents of Co and Mn are reduced. At this time, the ternary material can have a higher gram capacity, but Poor structural stability. From the perspective of electrochemical cells, increasing the relative content of Ni and decreasing the relative content of Co and Mn can increase the initial discharge gram capacity of the electrochemical cell, but it will deteriorate the cycle performance and storage performance.
  • the positive electrode active material of the present application has a core-shell structure, wherein the core is a bulk-doped ternary material, and its molecular formula is Li 1 + a [Ni x Co y Mn z M b M ′ c ] O 2-d Y d , Among them, the relative content of Ni is high, while the relative content of Co and Mn is low, so the positive electrode active material can have the advantage of high gram capacity. However, the thermal stability and structural stability of ternary materials with high Ni content inevitably decrease, which will inevitably deteriorate the cycle performance and storage performance of electrochemical cells.
  • Bulk doping of the ternary material in the core with M and M ′ as cationic doping elements can significantly improve the thermal and structural stability of the ternary material.
  • the doping elements M and M ′ can change the lattice constant of the ternary material or the valence state of some elements in the ternary material, reduce the relative content of Ni 4+ on the surface of the ternary material particle, and significantly increase the ternary material.
  • Thermal stability and structural stability of the ternary material at the same time improve the electronic and ionic conductivity of the ternary material, reduce the lithium nickel mixed in the ternary material, and then achieve the purpose of improving the cycling performance of the electrochemical cell.
  • Al 3+ can suppress the misalignment of Ni 2+ and Li + , thereby suppressing the phase transition of the ternary material during the charge and discharge process, and improving the structural stability of the ternary material. , And can well improve the cycling performance of electrochemical cells.
  • the doping element Y can replace part of O 2- , and since the doping element Y is halogen, halogen and transition metals (such as Ni, Co, Mn, etc.) have higher chemical bond energies than the chemical bond energies of oxygen and transition metals, which is conducive to further enhancing the thermal stability and structural stability of the ternary material, and at the same time, it can also reduce the corrosion of the ternary material by HF in the electrolyte .
  • the doping element Y is F.
  • the gradient distribution of the doping elements M, M ′, Y in the ternary material with decreasing mass concentration can also ensure that the improvement of the thermal stability and structural stability of the ternary material is more continuous and stable.
  • the coating of the ternary material with the oxide of the coating element M ′′ as the coating material can further prevent the ternary material from directly contacting the electrolyte, but it will not hinder the normal insertion and deintercalation of lithium ions.
  • the improvement of the surface properties of the ternary material by the cladding layer can also reduce the heat generation during charging and discharging.
  • the presence of the cladding layer can also suppress the phase transition of the ternary material and further improve the structural stability of the ternary material. .
  • a mass ratio of the cladding element M ′′ in the cladding layer to the doping element M ′ in the inner core is 1: (1 to 3).
  • the average particle diameter of the positive electrode active material is reached from the outermost side of the positive electrode active material (that is, the outer surface of the coating layer) toward the inner core at a position of 1/5.
  • the ratio of the sum of the masses of M, M ′, Y, and M ′′ to the total mass of M, M ′, Y, and M ′′ in the positive electrode active material is greater than 50%, and preferably 55% or more.
  • the above structure can ensure that the total content of modified elements (including doping elements M, M ′, Y, and cladding elements M ′′) in the surface layer of the positive electrode active material will not be too low, so that the positive electrode active material has high structural stability and high heat.
  • the stability of the electrochemical cell has the characteristics of excellent cycle performance.
  • the above structure can also ensure that the content of strong oxidizing nickel in the positive electrode active material is low, which can reduce the positive electrode active material (especially the ternary material core) and electrolysis.
  • the side reaction of the liquid has a good effect of suppressing gas generation.
  • the above structure can also ensure that the obtained positive electrode active material has good electronic and ionic conductivity, thereby making the DC resistance of the electrochemical cell relatively low. low.
  • M, M ′, Y, and M are within a thickness range from the outermost side of the positive electrode active material (that is, the outer surface of the coating layer) toward the inner core to a thickness of 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of "mass” is 90% or more, and preferably 93% or more, of the total mass of M, M ', Y, and M "in the positive electrode active material.
  • the diffusion depth of the doping elements M, M ′, Y in the inner core is too deep, or the radial concentration distribution is too wide, it will lead to an insignificant effect of improving the structural stability and thermal stability of the surface layer of the positive electrode active material, and The improvement effect of reducing the content of strongly oxidizing nickel is not obvious.
  • the crystal structure inside the positive electrode active material particles may be distorted, which affects its capacity.
  • the type of the cladding element M ′′ in the cladding layer and the doping element M ′ in the core may be the same or different, and there is no specific Limitation can be selected according to actual needs.
  • the type of the cladding element M ′′ in the cladding layer is the same as that of the doping element M ′ in the core, which is more conducive to the insertion and deintercalation of lithium ions. , which is more conducive to the performance of electrochemical cells.
  • the mass concentration of the doping element M in the core when the mass concentration of the doping element M in the core is small, the thermal stability and structural stability of the core may not be effectively improved, especially the degree of improvement in thermal stability is weak. Therefore, the cycle performance of the electrochemical cell cannot be effectively improved; when the mass concentration of the doping element M in the core is large, the gram capacity of the positive electrode active material is significantly reduced, which is disadvantageous for the initial discharge gram capacity of the electrochemical cell. Therefore, preferably, based on the total mass of the positive electrode active material, the mass concentration of the doping element M in the inner core is 100 ppm to 3000 ppm.
  • the thermal stability and structural stability of the core may not be effectively improved, especially the degree of improvement in structural stability is relatively small. Weak, and thus can not effectively improve the cycling performance of the electrochemical cell; when the mass concentration of the doping element M ′ in the core is large, the gram capacity of the positive electrode active material is significantly reduced, which is disadvantageous for the initial discharge gram capacity of the electrochemical cell. Therefore, preferably, based on the total mass of the positive electrode active material, the mass concentration of the doping element M ′ in the inner core is 100 ppm to 3000 ppm.
  • the mass concentration of the doping element Y in the core is 0 to 5000 ppm.
  • the mass concentration of the doped element Y in the core is 0, which means that the element Y may not be doped in the core.
  • the coating layer formed is usually thin, and may not effectively prevent direct contact between the core and the electrolyte. As a result, the effect of suppressing gas generation cannot be fully achieved; when the mass concentration of the coating element M ′′ in the coating layer is large, the coating layer formed is thicker, which will hinder the insertion and deintercalation of lithium ions to a certain extent.
  • the gram capacity of the active material is poor, which has a great impact on the performance of electrochemical cells. Therefore, preferably, based on the total mass of the positive electrode active material, the mass concentration of the coating element M ′′ in the coating layer is 100 ppm to 3000 ppm.
  • the thickness T of the coating layer is 0.001 ⁇ m to 0.5 ⁇ m; more preferably, the thickness T of the coating layer is 0.001 ⁇ m to 0.2 ⁇ m.
  • the positive electrode active material can better combine the characteristics of high gram capacity, high structural stability, and high thermal stability, so as to better improve the performance of the electrochemical cell.
  • the average particle diameter D50 of the positive electrode active material is 8 ⁇ m to 20 ⁇ m.
  • the homogeneity of the positive electrode sheet can be higher, which can avoid too small a particle size and the electrolyte from causing too many side reactions to affect the performance of the electrochemical cell, and can also prevent too large a particle size from hindering lithium Ions are transported inside the particles and affect the performance of the electrochemical cell.
  • the thickness T of the coating layer and the average particle diameter D50 of the positive electrode active material satisfy: 0.005 ⁇ T / D50 ⁇ 0.02.
  • the impurity lithium concentration in the positive electrode active material is 1500 ppm or less; more preferably, the impurity lithium concentration in the positive electrode active material is 700 ppm to 1500 ppm.
  • the impurity lithium in the positive electrode active material mainly includes alkaline lithium compounds in the form of lithium hydroxide and lithium carbonate. The presence of these impurity lithium not only affects the processing performance of the positive electrode sheet, but also affects the high temperature performance and safety of electrochemical cells. Impact on performance. The possible reasons are as follows: First, the impurity lithium is mainly an alkaline lithium compound.
  • the positive electrode active material of the present application has a core-shell structure.
  • the core ternary material is doped with a doping element (including cation doping or mixed doping of cation and anion).
  • the positive electrode active material may have the characteristics of high thermal stability and high structural stability.
  • the positive electrode active material of the present application can have a lower impurity lithium concentration, thereby ensuring better processing performance of the positive electrode sheet, and ensuring better high-temperature performance and safety performance of the electrochemical cell.
  • a method for preparing a positive electrode active material according to the second aspect of the present application for preparing the positive electrode active material according to the first aspect of the present application includes the steps:
  • the nickel-cobalt-manganese ternary material precursor, Li-containing compound, M-containing compound, M′-containing compound, and Y-containing compound are placed in a mixing device for mixing, and then sintered in an atmosphere furnace once;
  • step (1) The material after step (1) is sintered and washed in a washing solution, and then centrifuged and vacuum dried to obtain the core of the positive electrode active material, that is, the molecular formula is Li 1 + a [Ni x Co y Mn z M b M ′ c ] O 2-d Y d ternary material;
  • the core of the positive electrode active material and the M ′′ -containing compound are mixed in a mixing device, and then sintered in an atmosphere furnace to form a coating layer of the positive electrode active material to complete the preparation of the positive electrode active material.
  • the doping elements M, M ′, and Y can be obtained by sintering the nickel-cobalt-manganese ternary material precursor, Li-containing compound, M-containing compound, M′-containing compound, and Y-containing compound in one sintering.
  • the secondary sintering of the M ′′ compound can obtain a positive electrode active material with M ′′ oxide coating and M, M ′, Y bulk phase doping.
  • the precursor of the nickel-cobalt-manganese ternary material may be a nickel-cobalt-manganese oxide or a nickel-cobalt-manganese hydroxide.
  • the nickel-cobalt-manganese oxide and the nickel-cobalt-manganese hydroxide may be passed through a conventional Synthesis by secondary drying or co-precipitation.
  • the type of the Li-containing compound is not specifically limited, and can be selected according to actual needs.
  • the lithium-containing compound may be lithium hydroxide, lithium carbonate, lithium nitrate, or the like.
  • the types of the M-containing compound and the M′-containing compound are not specifically limited, and may be selected according to actual needs.
  • the M-containing compound may be selected from M oxides, M chlorides, M sulfates, M nitrates, M carbonates, M bicarbonates, and the like;
  • M′-containing compounds may be selected from M 'Oxide, M' chloride, M 'sulfate, M' nitrate, M 'carbonate, M' bicarbonate, and the like.
  • the type of the Y-containing compound is also not particularly limited, and can be selected according to actual needs.
  • the Y-containing compound may be selected from the ammonium salt of Y or the lithium salt of Y, and may be, for example, NH 4 F, NH 4 Cl, NH 4 Br, LiF, LiCl, LiBr, and the like.
  • the mixing time is not specifically limited, and can be selected according to actual needs, as long as the nickel-cobalt-manganese ternary material precursor, Li-containing compound, M-containing compound, M′-containing compound, and Y-containing compound are mixed uniformly Just fine.
  • the mixing time is from 0.5h to 3h.
  • the primary sintering atmosphere in the atmosphere furnace may be air or oxygen; preferably, the primary sintering atmosphere is oxygen; more preferably, the oxygen concentration in the atmospheric furnace is 50% to 100%; even more preferably, the atmospheric furnace The middle oxygen concentration is 80% to 100%.
  • the primary sintering temperature is preferably 700 ° C to 950 ° C.
  • the primary sintering time is 5h to 25h; more preferably, the primary sintering time is 10h to 20h.
  • the washing solution may be deionized water or a boron-containing compound solution.
  • the solvent in the boron-containing compound solution may be deionized water, ethanol, or a mixed solvent of the two.
  • the solute boron-containing compound may be selected from B 2 O 3 , H 3 BO 3 , C 6 H 5 B (OH) 2 , One or more of C 3 H 9 B 3 O 6 and (C 3 H 7 O) 3 B.
  • the concentration of the boron-containing compound solution may be 0.01 mol / L to 1 mol / L.
  • the washing temperature is preferably 10 ° C to 50 ° C; more preferably, the washing temperature is 20 ° C to 40 ° C.
  • the washing time is from 1 min to 60 min; more preferably, the washing time is from 2 min to 30 min.
  • the stirring speed during washing is from 10 r / min to 500 r / min; more preferably, the stirring speed during washing is from 20 r / min to 200 r / min.
  • step (2) in order to achieve a better washing effect, preferably, the mass ratio of the material to the washing liquid after the first sintering is 1: (0.5 to 10); more preferably, the material and the washing after the first sintering are completed The mass ratio of the liquid was 1: (1 to 5).
  • the vacuum drying temperature is preferably 80 ° C to 150 ° C; more preferably, the vacuum drying temperature is 90 ° C to 120 ° C.
  • the time for vacuum drying is 2h-20h; more preferably, the time for vacuum drying is 5h-10h.
  • the type of the M ′′ -containing compound is not specifically limited, and may be selected according to actual needs.
  • the M ′′ -containing compound may be selected from M ′′ oxides, M ′′ chlorides, and M ′′ sulfuric acid. Salt, M ′′ nitrate, M ′′ carbonate, M ′′ bicarbonate, and the like.
  • the mixing time is not specifically limited, and can be selected according to actual needs, as long as the core of the positive electrode active material and the M ′′ -containing compound are mixed uniformly.
  • the mixing time is 0.5h to 3h.
  • the secondary sintering atmosphere in the atmosphere furnace may be air or oxygen, preferably, the secondary sintering atmosphere is oxygen; more preferably, the oxygen concentration in the atmosphere furnace is 50% to 100%; even more preferably, The oxygen concentration in the atmosphere furnace is 80% to 100%.
  • the secondary sintering temperature is 200 ° C to 500 ° C.
  • the secondary sintering time is 5h to 25h; more preferably, the secondary sintering time is 5h to 10h.
  • step (1) the types of the M′-containing compound and the M ′′ -containing compound may be the same or different, and may be selected according to actual needs.
  • step (1) The type of the M′-containing compound is the same as that of the M ′′ -containing compound in step (3).
  • FIG. 1 is a perspective view of an embodiment of an electrochemical cell 5.
  • FIG. 2 is an exploded view of FIG. 1.
  • FIG. 3 is a schematic diagram of an embodiment of the electrode assembly 52 of the electrochemical cell 5 of FIG. 2, in which the first electrode piece 521, the second electrode piece 522, and the separator 523 are wound to form a wound electrode assembly.
  • FIG. 4 is a schematic diagram of another embodiment of the electrode assembly 52 of the electrochemical cell 5 of FIG. 2, wherein the first electrode piece 521, the second electrode piece 522, and the separator 523 are stacked in a thickness direction to form a laminated electrode assembly.
  • the electrochemical cell 5 includes a case 51, an electrode assembly 52, a top cover assembly 53, and an electrolyte (not shown).
  • the electrode assembly 52 is housed in the case 51.
  • the electrode assembly 52 includes a first pole piece 521, a second pole piece 522, a separation film 523, a first pole tab 524, and a second pole tab 525.
  • the isolation film 523 separates the first pole piece 521 and the second pole piece 522.
  • the first pole piece 521 includes a first current collector 521a and a first active material layer 521b disposed on a surface of the first current collector 521a.
  • the first active material layer 521b contains a first active material.
  • the first active material layer 521b may be disposed on one surface or both surfaces of the first current collector 521a according to actual needs.
  • the second pole piece 522 includes a second current collector 522a and a second active material layer 522b disposed on a surface of the second current collector 522a.
  • the second active material layer 522b may be disposed on one surface or both surfaces of the second current collector 522a according to actual needs.
  • the second active material layer 522b contains a second active material.
  • the first active material and the second active material achieve de-intercalation of active ions (for example, lithium ions for a lithium ion battery).
  • the first pole piece 521 and the second pole piece 522 are electrically opposite, that is, one of the first pole piece 521 and the second pole piece 522 is a positive pole piece and the other of the first pole piece 521 and the second pole piece 522 is Negative plate.
  • the first tab 524 may be formed by cutting the first current collector 521a or formed separately and fixedly connected to the first current collector 521a.
  • the second tab 525 may be formed by cutting the second current collector 522a or separately formed and fixedly connected to the second current collector 522a.
  • the number of the electrode assemblies 52 is not limited, and may be one or more.
  • the electrolyte is injected into the case 51 and impregnates the electrode assembly 51, specifically, the first electrode piece 521, the second electrode piece 522, and the separator 523.
  • the electrochemical cell 5 shown in FIG. 1 is a can-type battery, but is not limited thereto.
  • the electrochemical cell 5 may be a pouch-type battery, that is, the case 51 is replaced by a metal plastic film and the top cover assembly 53 is eliminated.
  • the current collector of the positive electrode sheet is a positive electrode current collector
  • the active material layer of the positive electrode sheet is a positive electrode active material layer.
  • the active material of the sheet is a positive electrode active material. Therefore, the positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer disposed on the positive electrode current collector, and the positive electrode active material layer includes the positive electrode active material described in the first aspect of the present application.
  • the type of the separator is not specifically limited, and may be any separator material used in existing electrochemical cells, such as polyethylene, polypropylene, and polyvinylidene fluoride. Ethylene and their multilayer composite films are not limited to these.
  • the specific type and composition of the electrolyte are not specifically limited, and can be selected according to actual needs.
  • the electrochemical battery may be a lithium-ion battery, a metal lithium battery, an all-solid-state lithium battery, or a super capacitor.
  • the electrochemical cell is a lithium ion battery are shown, but the present application is not limited thereto.
  • FIG. 5 is a perspective view of an embodiment of the battery module 4. 5, the battery module 4 includes a plurality of electrochemical cells 5. A plurality of electrochemical cells 5 are arranged in the longitudinal direction.
  • the battery module 4 can be used as a power source or an energy storage device.
  • a battery module 4 provided in a fourth aspect of the present application includes the electrochemical cell 5 described in the third aspect of the present application.
  • the number of the electrochemical cells 5 included in the battery module 4 can be adjusted according to the application and capacity of the battery module 4.
  • a battery pack describing the fifth aspect of the present application is followed.
  • FIG. 6 is a perspective view of an embodiment of the battery pack 1.
  • FIG. 7 is an exploded view of FIG. 6.
  • the battery pack 1 includes an upper case 2, a lower case 3, and a battery module 4.
  • the upper case 2 and the lower case 3 are assembled together to form a space for accommodating the battery module 4.
  • the battery module 4 is placed in the space of the upper case 2 and the lower case 3 assembled together.
  • the output electrode of the battery module 4 is penetrated from one or both of the upper case 2 and the lower case 3 to supply power to the outside or charge from the outside.
  • the number and arrangement of the battery modules 4 used in the battery pack 1 can be determined according to actual needs.
  • the battery pack 1 can be used as a power source or an energy storage device.
  • the battery pack provided by the fifth aspect of the present application includes the battery module 4 according to the fourth aspect of the present application.
  • FIG. 8 is a schematic diagram of an embodiment of a device using an electrochemical cell as a power source.
  • the device provided by the sixth aspect of the present application includes the electrochemical cell 5 according to the third aspect of the present application, and the electrochemical cell is used as a power source of the device.
  • the device using the electrochemical cell 5 is an electric vehicle.
  • the electrochemical cell 5 can be used as a power source of the device.
  • the device using the electrochemical cell 5 may be any electric vehicle (e.g., electric bus, electric tram, electric bicycle, electric motorcycle, electric scooter, electric golf cart, electric truck) ), Electric ships, electric tools, electronic equipment and energy storage systems.
  • the electric vehicle may be an electric pure electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle.
  • the device provided in the sixth aspect of the present application may include the battery module 4 described in the fourth aspect of the present application.
  • the device provided in the sixth aspect of the present application may also include the device provided in the fifth aspect of the present application. Mentioned battery pack 1.
  • a lithium-ion battery is taken as an example, and the embodiment is used to further explain the present application. It should be understood that these examples are only used to illustrate the present application and not to limit the scope of the present application.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the core is 100 ppm
  • the mass concentration of the M ′ element in the core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1500 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the sum of the mass concentrations of the Ti element and the Al element is 2160 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentration of the Ti element and the Al element is 3348 ppm, and the ratio of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 93%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the core is 1500 ppm
  • the mass concentration of the M ′ element in the core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1500 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material within a thickness ranging from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 3000 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentrations of the Ti element and the Al element is 4650 ppm
  • the ratio of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 93%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 3000 ppm
  • the mass concentration of the M ′ element in the inner core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1500 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the sum of the mass concentrations of the Ti element and the Al element is 3900 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the contents of the Ti element and the Al element is 6045 ppm, and the ratio of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 93%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the core is 1500 ppm
  • the mass concentration of the M ′ element in the core is 100 ppm
  • the mass concentration of the M ′′ element in the coating layer is 100 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material in a thickness range from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 1020 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • mass concentration within, Ti, and Al-element and the element is 1581ppm, the quality of the elements Al and Ti element based on the total mass of the positive electrode active material of Ti element and Al element ratio of 93% w 2.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the core is 1500 ppm
  • the mass concentration of the M ′ element in the core is 1500 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1500 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the sum of the mass concentrations of the Ti element and the Al element is 2700 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentration of the Ti element and the Al element is 4185 ppm, and the proportion of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 93%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 1500 ppm
  • the mass concentration of the M ′ element in the inner core is 3000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 3000 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material within a thickness range from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 4500 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentration of the Ti element and the Al element is 6975 ppm, and the proportion of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 93%.
  • the precursor of the ternary material is [Ni 0.70 Co 0.15 Mn 0.15 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compounds are zirconia (ZrO 2 )
  • M′-containing compound is boron trioxide (B 2 O 3 )
  • M ′′ -containing compounds are boron trioxide (B 2 O 3 )
  • the mass concentration of the M element in the core is 1500 ppm
  • the mass concentration of the M ′ element in the core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1000 ppm.
  • ternary material precursor [Ni 0.70 Co 0.15 Mn 0.15 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), zirconium dioxide (ZrO 2 ), and boron trioxide (B 2 O 3 )
  • the mixing is performed in a high-speed mixer. After the mixing for 1 hour, the sintering is performed in an atmosphere sintering furnace with an O 2 concentration of 90%, wherein the sintering temperature is 850 ° C. and the sintering time is 20 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and B 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode activity.
  • the sum of the mass concentrations of the Zr element and the B element is 2475 ppm, Zr
  • the ratio of the mass of element B and element B to the total mass of Zr element and B element in the positive electrode active material w 1 is 55%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material
  • the sum of the mass concentration of the Zr element and the B element is 4095 ppm
  • the ratio of the mass of the Zr element and the B element to the total mass of the Zr element and the B element in the positive electrode active material is w 2 is 91%.
  • the precursor of the ternary material is [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compounds are calcium oxide (CaO)
  • M′-containing compounds are magnesium oxide (MgO)
  • M ′′ -containing compounds are magnesium oxide (MgO)
  • the mass concentration of the M element in the inner core is 2000 ppm
  • the mass concentration of the M ′ element in the inner core is 3000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1000 ppm.
  • the ternary material precursor [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), calcium oxide (CaO), and magnesium oxide (MgO) were placed in a high-speed mixer and mixed. After mixing for 1 hour, the sintering was carried out in an atmosphere sintering furnace with an O 2 concentration of 90%. The sintering temperature was 750 ° C. and the sintering time was 20 h.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and MgO are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a package of positive electrode active materials.
  • the cladding layer has a secondary sintering temperature of 200 ° C. and a secondary sintering time of 5 h. After the secondary sintering is completed, the required positive active material is obtained.
  • the obtained positive electrode active material in a thickness range from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentration of Ca element and Mg element is 4320 ppm, Ca The ratio of the mass of element and Mg element to the total mass of Ca element and Mg element in the positive electrode active material w 1 is 72%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentrations of the Ca element and the Mg element is 5820 ppm, and the ratio of the mass of the Ca element and the Mg element to the total mass of the Ca element and the Mg element in the positive electrode active material w 2 is 97%.
  • the precursor of the ternary material is [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compounds are calcium oxide (CaO)
  • M′-containing compounds are a mixture of boron trioxide (B 2 O 3 ) and aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are a mixture of boron trioxide (B 2 O 3 ) and aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 2000 ppm
  • the mass concentration of the M ′ element in the inner core is 3000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1000 ppm.
  • the ternary material precursor [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), calcium oxide (CaO), boron trioxide (B 2 O 3 ), Aluminum (Al 2 O 3 ) is placed in a high-speed mixer for mixing. After mixing for 1 hour, it is placed in an atmosphere sintering furnace with an O 2 concentration of 90% for one sintering, wherein the primary sintering temperature is 800 ° C and the primary The sintering time is 10h.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material is mixed with B 2 O 3 and Al 2 O 3 in a high-speed mixer, and after mixing for 2 hours, it is placed in an atmosphere sintering furnace with an O 2 concentration of 90% for two hours.
  • the secondary sintering forms a coating layer of the positive electrode active material.
  • the secondary sintering temperature is 200 ° C. and the secondary sintering time is 5 hours. After the secondary sintering is completed, the required positive electrode active material is obtained.
  • the sum of the mass concentrations of Ca, B, and Al is 3840ppm, the quality of Ca element, B element and Al element on the total mass of the positive electrode active material and Ca, B element and Al element ratio w 1 was 64%; the outermost reaches material mean of the positive electrode active to the kernel direction from the positive electrode active material In the thickness range of 2/3 of the particle diameter, the sum of the mass concentrations of Ca, B, and Al is 5700 ppm.
  • the mass of Ca, B, and Al accounts for Ca, B, and Al in the positive electrode active material.
  • the proportion w 2 of the total mass is 95%.
  • the precursor of the ternary material is [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are boron trioxide (B 2 O 3 )
  • the mass concentration of the M element in the inner core is 2500 ppm
  • the mass concentration of the M ′ element in the inner core is 2400 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1200 ppm.
  • the ternary material precursor [Ni 0.85 Co 0.10 Mn 0.05 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture. Mixing is performed in a feeder. After 2 hours of mixing, it is placed in an atmosphere sintering furnace with an O 2 concentration of 80% for one sintering, wherein the primary sintering temperature is 800 ° C. and the primary sintering time is 10 h.
  • the material after the primary sintering was placed in a 0.05 mol / L boric acid aqueous solution for washing.
  • the mass ratio of the material to the washing solution was 1: 0.5, the washing temperature was 40 ° C, the washing time was 10 minutes, and the stirring speed during washing was 100 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 120 ° C. for 5 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and B 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 80% for secondary sintering to form positive electrode activity.
  • the sum of the mass concentrations of Ti element, Al element, and B element is 3904ppm, the proportion of the mass of Ti element, Al element, and B element in the total mass of Ti element, Al element, and B element in the positive electrode active material w 1 is 64%; the average value of the positive electrode active material is reached from the outermost side of the positive electrode active material toward the inner core.
  • the sum of the mass concentrations of the Ti element, the Al element, and the B element is 5795 ppm.
  • the masses of the Ti element, the Al element, and the B element account for the Ti element, the Al element, and the B element in the positive electrode active material.
  • the proportion w 2 of the total mass is 95%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 0Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compounds are titanium dioxide (TO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 2000 ppm
  • the mass concentration of the M ′ element in the inner core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 400 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 0Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum oxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the material is mixed in a feeder. After the material is mixed for 0.5 h, it is placed in an atmosphere sintering furnace with an O 2 concentration of 100% for primary sintering, wherein the primary sintering temperature is 900 ° C. and the primary sintering time is 15 h.
  • the material after the primary sintering was placed in a 1 mol / L C 5 H 6 B (OH) 2 ethanol and water mixed solution for washing, wherein the mass ratio of the material to the washing solution was 1: 5 and the washing temperature was 30 °C, washing time is 2min, stirring speed is 20rpm during washing; centrifugal separation after washing is completed, and then the solid material after centrifugation is dried in a vacuum drying box at 120 ° C for 10h to obtain a bulk-doped ternary material , That is, the core of the positive active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after mixing for 0.5 h, they are placed in an atmosphere sintering furnace with an O 2 concentration of 100% for secondary sintering.
  • the secondary sintering temperature is 250 ° C. and the secondary sintering time is 5 h. After the secondary sintering is completed, the required positive electrode active material is obtained.
  • the obtained positive electrode active material in a thickness range from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 2200 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 50%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • mass concentration within, the elements Ti, Al element and is 4180ppm, the quality of the elements Ti, Al element representing the Ti element in the positive electrode active material, the total mass of the Al element ratio of 95% w 2.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 100 ppm
  • the mass concentration of the M ′ element in the inner core is 3000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 3000 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the material is mixed in a feeder. After the material is mixed for 0.5 h, it is placed in an atmosphere sintering furnace with an O 2 concentration of 100% for primary sintering, wherein the primary sintering temperature is 900 ° C. and the primary sintering time is 15 h.
  • the material after sintering was placed in a 0.8 mol / L (C 3 H 7 O) 3 B ethanol solution for washing, wherein the mass ratio of the material to the washing solution was 1: 3, the washing temperature was 35 ° C, and the washing time It is 3min, the stirring speed is 200rpm during washing; centrifugal separation is performed after washing, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C for 10h to obtain a bulk-doped ternary material, that is, positive electrode activity The core of the material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 1.5 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 100% for secondary sintering.
  • the secondary sintering temperature is 250 ° C and the secondary sintering time is 5 hours. After the secondary sintering is completed, the required positive electrode active material is obtained.
  • the obtained positive electrode active material in a thickness range from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 3660 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 60%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • mass concentration within, the elements Ti, Al element and is 4880ppm, the quality of the elements Ti, Al element representing the Ti element in the positive electrode active material, the total mass of the Al element ratio of 80% w 2.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the Y-containing compound is NH 4 F.
  • the mass concentration of the M element in the core is 100 ppm
  • the mass concentration of the M ′ element in the core is 2000 ppm
  • the mass concentration of the Y element is 1000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 600 ppm.
  • Ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), aluminum trioxide (Al 2 O 3 ), ammonia fluoride (NH 4 F) is placed in a high-speed mixer for mixing. After mixing for 1 hour, it is placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering. The primary sintering temperature is 830 ° C and the primary sintering time For 15h.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material within a thickness ranging from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of Ti element, Al element, and F element is 2331ppm, the proportion of the mass of Ti element, Al element, and F element in the total mass of Ti element, Al element, and F element in the positive electrode active material w 1 is 63%; the average value of the positive electrode active material is reached from the outermost side of the positive electrode active material toward the inner core.
  • the sum of the mass concentrations of the Ti element, the Al element, and the F element is 3367 ppm, and the masses of the Ti element, the Al element, and the F element account for the Ti element, the Al element, and the F element in the positive electrode active material.
  • the proportion w 2 of the total mass is 91%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • the mass concentration of the M element was 50 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), and titanium dioxide (TiO 2 ) were mixed in a high-speed mixer for 1 hour.
  • the sintering is performed in an atmosphere sintering furnace with an O 2 concentration of 90%.
  • the sintering temperature is 830 ° C. and the sintering time is 15 hours. After the sintering is completed, the required positive electrode active material is obtained.
  • the obtained positive electrode active material within a thickness range from the outermost side of the positive electrode active material to the average particle diameter of the positive electrode active material at 1/5, the ratio of the mass of the Ti element to the total mass of the Ti element in the positive electrode active material w 1 45%; from the outermost positive electrode active material reached a thickness within the range of 2/3 of an average particle diameter of the positive electrode active material, the total mass of the Ti element in the positive electrode active material in the mass of Ti element ratio of 94% w 2.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element is 2000 ppm
  • the mass concentration of the M ′ element is 2000 ppm
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the material is mixed in a feeder. After mixing for 0.5h, it is sintered in an atmosphere sintering furnace with an O 2 concentration of 100%.
  • the sintering temperature is 830 ° C and the sintering time is 15h. After the sintering, bulk phase doping is obtained.
  • the masses of the Ti element and the Al element account for the Ti element and the Al element in the positive electrode active material.
  • the proportion of total mass w 1 is 45%; from the outermost side of the positive electrode active material to a thickness range of 2/3 of the average particle diameter of the positive electrode active material, the mass of the Ti element and the Al element accounts for the Ti element and the Al element in the positive electrode active material.
  • the proportion w 2 of the total mass is 94%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M ′′ element in the coating layer was 2000 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and lithium hydroxide (LiOH ⁇ H 2 O) were mixed in a high-speed mixer, and after mixing for 1 hour, the mixture was placed in an O 2 concentration.
  • the primary sintering was performed in a 90% atmosphere sintering furnace, wherein the primary sintering temperature was 830 ° C and the primary sintering time was 15 hours.
  • the mass of the Al element accounts for the total mass of the Al element in the positive electrode active material.
  • the ratio w 1 is 94%; within a thickness range from the outermost side of the positive electrode active material to the inner core to a thickness of 2/3 of the average particle diameter of the positive electrode active material, the ratio of the mass of the Al element to the total mass of the Al element in the positive electrode active material w 2 is 98%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the core is 5000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 1000 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and lithium hydroxide (LiOH ⁇ H 2 O) titanium dioxide (TiO 2 ) were mixed in a high-speed mixer for 1 h.
  • the sintering was carried out in an atmosphere sintering furnace with an O 2 concentration of 90%, wherein the sintering temperature was 830 ° C. and the sintering time was 15 h.
  • the mass of Ti element and Al element accounted for Ti element in the positive electrode active material.
  • the total mass of the Al element ratio of 56% w 1; from the positive electrode active material reaches the outermost side within the thickness direction of the core average particle diameter of the positive electrode active material of 2/3, Ti element, an Al element mass accounted for the positive active material
  • the proportion w 2 of the total mass of the Ti element and the Al element was 96%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 1500 ppm
  • the mass concentration of the M ′ element in the inner core is 4800 ppm
  • the mass concentration of the M ′′ element in the coating layer is 800 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material within a thickness ranging from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentration of the Ti element and the Al element is 3053 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 43%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • the sum of the mass concentration of the Ti element and the Al element is 6887 ppm
  • the ratio of the mass of the Ti element and the Al element to the total mass of the Ti element and the Al element in the positive electrode active material is w 2 is 97%.
  • the precursor of the ternary material is [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 and the mass is 4300g
  • Li-containing compound is lithium hydroxide (LiOH ⁇ H 2 O), mass is 2035g
  • M-containing compound is titanium dioxide (TiO 2 )
  • M′-containing compound is aluminum oxide (Al 2 O 3 )
  • M ′′ -containing compounds are aluminum oxide (Al 2 O 3 )
  • the mass concentration of the M element in the inner core is 1500 ppm
  • the mass concentration of the M ′ element in the inner core is 2000 ppm
  • the mass concentration of the M ′′ element in the coating layer is 4000 ppm.
  • the ternary material precursor [Ni 0.8 Co 0.1 Mn 0.1 ] (OH) 2 , lithium hydroxide (LiOH ⁇ H 2 O), titanium dioxide (TiO 2 ), and aluminum trioxide (Al 2 O 3 ) were placed in a high-speed mixture.
  • the materials are mixed in a feeder. After the materials are mixed for 1 hour, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for primary sintering.
  • the primary sintering temperature is 830 ° C and the primary sintering time is 15 hours.
  • the material after the primary sintering was washed in a 0.05 mol / L boric acid aqueous solution, wherein the mass ratio of the material to the washing solution was 1: 2, the washing temperature was 20 ° C, the washing time was 5 minutes, and the stirring speed during washing was 200 rpm; centrifugal separation after washing is completed, and then the centrifuged solid material is dried in a vacuum drying box at 100 ° C. for 10 h to obtain a bulk-doped ternary material, that is, the core of the positive electrode active material.
  • the bulk-doped ternary material and Al 2 O 3 are mixed in a high-speed mixer, and after 2 hours of mixing, they are placed in an atmosphere sintering furnace with an O 2 concentration of 90% for secondary sintering to form a positive electrode.
  • the obtained positive electrode active material within a thickness ranging from the outermost side of the positive electrode active material toward the inner core to a thickness of 1/5 of the average particle diameter of the positive electrode active material, the sum of the mass concentrations of the Ti element and the Al element is 4875 ppm, and Ti
  • the proportion of the mass of element and Al to the total mass of Ti element and Al element in the positive electrode active material w 1 is 65%; the thickness range from the outermost side of the positive electrode active material to the inner core reaches 2/3 of the average particle diameter of the positive electrode active material.
  • mass concentration within, and Ti element and Al element is 7125ppm, the quality of the elements Ti, Al element representing the Ti element in the positive electrode active material, the total mass of the Al element ratio of 95% w 2.
  • the content of lithium in the positive electrode active material was measured by acid-base titration. 30g of the positive electrode active material samples prepared in the examples and comparative examples were put into 100ml of pure water, stirred for 30min, and then allowed to stand for 5min. After suction filtration, 10ml of the supernatant was taken and the positive electrode active material sample was titrated with a 0.05mol / L hydrochloric acid standard solution. Dissolved lithium carbonate and lithium hydroxide in the pH electrode as the indicator electrode, determine the end point by means of the jump caused by potential changes, and calculate the impurity lithium content in the positive electrode active material.
  • ethylene carbonate (EC), diethyl carbonate (DEC), and dimethyl carbonate (DMC) are mixed at a volume ratio of 1: 1: 1 to obtain an organic solvent, and then sufficiently dried LiPF 6 is dissolved in the mixed organic In the solvent, an electrolytic solution having a concentration of 1 mol / L was prepared.
  • a lithium button was used as a negative electrode, and the prepared positive electrode was assembled into a standard button battery.
  • the ratio of the discharge capacity D 0 to the mass of the positive electrode active material is the gram capacity of the positive electrode active material.
  • the first Coulombic efficiency (%) of the positive electrode active material D 0 / C 0 ⁇ 100%.
  • the positive electrode active materials prepared in the examples and comparative examples were assembled into a lithium ion battery according to the following method.
  • negative electrode sheet the negative electrode active material artificial graphite and hard carbon, conductive agent acetylene black, binder styrene-butadiene rubber (SBR), thickener sodium carboxymethyl cellulose (CMC) according to the mass ratio of 90: 5: 2: 2: 1 mixed, added solvent deionized water, and stirred under the action of a vacuum stirrer until the system was uniform, to obtain a negative electrode slurry; the negative electrode slurry was evenly coated on both surfaces of the negative electrode current collector copper foil After drying at room temperature, it was transferred to an oven to continue drying, and then cold-pressed and cut to obtain negative electrode pieces.
  • SBR binder styrene-butadiene rubber
  • CMC thickener sodium carboxymethyl cellulose
  • ethylene carbonate (EC), diethyl carbonate (DEC) and dimethyl carbonate (DMC) are mixed at a volume ratio of 1: 1: 1 to obtain an organic solvent, and then the fully dried LiPF 6 was dissolved in the mixed organic solvent and prepared into an electrolytic solution having a concentration of 1 mol / L.
  • a polyethylene (PE) film is used as a separator.
  • Preparation of lithium ion battery stack the positive electrode sheet, the separator, and the negative electrode sheet in order, so that the separator is located between the positive and negative electrode sheets to play a role of isolation, and then wound to obtain a bare cell;
  • the bare cell is placed in an outer packaging shell, and the electrolyte is injected after drying. After the steps of vacuum packaging, standing, forming, and shaping, a lithium ion battery is obtained.
  • the lithium-ion battery In a 25 ° C constant temperature environment, the lithium-ion battery is allowed to stand for 5 minutes, then discharged to 2.8V at a constant current of 1 / 3C, left to stand for 5 minutes, and then charged to 4.25V at a constant current of 1 / 3C, and then charged at a constant voltage of 4.25V. Until the current is less than or equal to 0.05mA, and let stand for 5min, the charging capacity at this time is recorded as C 0 ; and then discharged at 1 / 3C constant current to 2.8V, and the discharging capacity at this time is recorded as D 0 .
  • the ratio of the discharge capacity D 1 to the mass of the positive electrode active material is the initial gram capacity of the lithium-ion battery.
  • the lithium-ion battery In a 25 ° C constant temperature environment, charge the lithium-ion battery to 4.25V at a constant current of 1C, then charge to a current of ⁇ 0.05mA at a constant voltage of 4.25V, leave it for 5 minutes, and then discharge to 2.8V at 1C constant current.
  • the current discharge capacity is the discharge capacity of the first cycle. Then, the lithium-ion battery was subjected to a 1200 cycle charge / discharge test according to the above method, and the discharge capacity at the 1200th cycle was detected.
  • Lithium-ion battery capacity retention rate (%) after 1200 cycles at 25 ° C (discharge capacity at 1200th cycle / discharge capacity at first cycle) x 100%.
  • the lithium-ion battery In a constant temperature environment at 45 ° C, charge the lithium-ion battery to 4.25V at a constant current of 1C, and then charge to a current of ⁇ 0.05mA at a constant voltage of 4.25V, leave it for 5 minutes, and then discharge to 2.8V at 1C constant current.
  • the current discharge capacity is the discharge capacity of the first cycle. Then, the lithium-ion battery was subjected to a charge / discharge test for 800 cycles according to the above method, and the discharge capacity at the 800th cycle was detected.
  • the capacity retention rate (%) of the lithium ion battery after 800 cycles at 45 ° C. (Discharge capacity at the 800th cycle / discharge capacity at the first cycle) ⁇ 100%.
  • the volume expansion rate (%) of a lithium ion battery after storage at 80 ° C. for 10 days (V 10 / V 1 -1) ⁇ 100%.
  • the positive electrode active materials prepared in Comparative Examples 1-4 generally have problems of high impurity lithium content and low gram capacity, and lithium ion batteries generally have low initial discharge gram capacity, poor performance at room temperature and high temperature, The problem of poor high temperature storage performance.
  • the positive electrode active material of Comparative Example 1 is only doped with a small amount of Ti element and has no coating layer.
  • the positive electrode active material has a high impurity lithium content and a low gram capacity.
  • the normal temperature cycling performance and high temperature cycling performance of the lithium ion battery And high temperature storage performance are poor.
  • the positive electrode active material of Comparative Example 2 was doped with both Ti element and Al element, but also without a coating layer. Compared with Comparative Example 1, the impurity lithium content of the positive electrode active material was reduced, and the gram capacity and The initial discharge gram capacity of the lithium-ion battery has been improved. The normal-temperature cycling performance, high-temperature cycling performance, and high-temperature storage performance of the lithium-ion battery have also improved to some extent, but the improvement is limited. The possible reason is that the content of strong nickel oxide in the positive electrode active material is still high, and there are many side reactions between the electrolyte and the positive electrode active material, so the phenomenon of flatness of lithium ion batteries is still serious.
  • the positive electrode active material of Comparative Example 3 only contains a coating layer. Compared with Comparative Example 1, the impurity lithium content of the positive electrode active material is reduced, and the gram capacity of the positive electrode active material and the initial discharge gram capacity of the lithium ion battery are increased. The lithium-ion battery's normal-temperature cycling performance, high-temperature cycling performance, and high-temperature storage performance have also improved, but the degree of improvement is limited. The possible reason is that the ternary material core of the positive electrode active material has poor thermal stability and structural stability.
  • the layered structure of the ternary material may collapse, thereby making the performance of the lithium ion battery, especially the cycle performance, still poor.
  • the positive phase of the positive electrode active material of Comparative Example 4 was doped with a higher content of Ti element, and the surface was also coated with Al 2 O 3. Compared with Comparative Example 1, the lithium content of the positive electrode active material was reduced, and lithium The normal-temperature cycling performance, high-temperature cycling performance, and high-temperature storage performance of the ion battery have improved slightly, but the degree of improvement is limited. Possible reason is that the ternary material having a positive electrode active material core poor structural stability, in a lithium ion battery during repeated charge and discharge, since the Ni 2+ and Li + shuffling increasing proportion of ternary material of the core The layered structure may collapse, so that the performance of the lithium ion battery, especially the cycle performance, is still poor.
  • the positive electrode active material was simultaneously doped with the bulk phases of the doping elements M, M ′, Y and the oxide of the covering element M ′′.
  • the positive electrode active material may have a high gram capacity and a high structure. The characteristics of stability and high thermal stability, while the lithium content of the positive electrode active material is low, can make the lithium ion battery have a high initial discharge gram capacity, while having excellent normal temperature and high temperature cycle performance and high temperature storage performance.
  • Comparative Example 5 although the positive electrode active material was simultaneously doped with bulk phases of the doping elements Ti and Al and covered with Al 2 O 3 , the mass ratio of Al in the coating layer to the bulk-doped Al was 1 : 6, that is, the content of Al in the coating layer is too small, and it is difficult to ensure that the surface layer portion of the positive electrode active material has high structural stability and high thermal stability.
  • Comparative Example 6 although the positive electrode active material was simultaneously doped with the bulk phases of the doping elements Ti and Al and covered with Al 2 O 3 , the mass ratio of Al in the coating layer to the bulk-doped Al was 1 : 0.5, that is, the content of Al in the coating layer is too high, and the blocking layer has an excessively large blocking effect on lithium ion insertion and deintercalation, which affects the gram capacity of the positive electrode active material and further affects the performance of the lithium ion battery.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Composite Materials (AREA)
  • Organic Chemistry (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Secondary Cells (AREA)

Abstract

一种正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置。所述正极活性材料包括内核以及包覆层，所述包覆层包覆于所述内核的表面。所述内核选自分子式为Li 1+a[Ni xCo yMn zM bM' c]O 2-dY d的三元材料，其中，掺杂元素M选自Zr、Ti、Te、Sb、Ca、Si中的一种或几种，掺杂元素M'选自Mg、Zn、Al、B、Ce、Fe中的一种或几种，掺杂元素Y选自F、Cl、Br中的一种或几种，-0.1≤a≤0.2、0≤d≤0.1、0.7≤x<1、0<y<0.3、0<z<0.3、0<b≤0.1、0<c≤0.1且x+y+z+b+c＝1，掺杂元素M、M'、Y各自在所述内核中的分布满足：从所述内核外侧到所述内核中心具有减小的质量浓度梯度，所述包覆层物质为包覆元素M"的氧化物，且M"选自Mg、Zn、Al、B、Ce、Fe中一种或几种。其中，所述包覆层中的包覆元素M"与所述内核中的掺杂元素M'的质量比为1:(1～5)。该正极活性材料具有高克容量、高结构稳定性以及高热稳定性的特点，且能使电化学电池在具有高初始放电克容量的同时兼具优异的循环性能和存储性能。

Description

正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置 技术领域
本申请涉及一种正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置。
背景技术
燃油车保有量的逐年剧增，不仅使化石燃料等不可再生能源的消耗与日俱增，同时也加速了环境、大气的污染。电动车被认为是燃油车的较好替代品，因而作为其核心组件的车用动力锂离子电池近年来受到了人们的深入研究，动力锂离子电池的正极活性材料在短短十年左右的时间里完成了从NCM111到NCM523、NCM622，以及到NCM811的快速更新换代。随着正极活性材料中镍含量的大幅度提升，动力锂离子电池的能量密度得到了大幅度提高，但这意味着其中稳定结构的锰、以及促进循环的钴的含量会相应降低，因此使动力锂离子电池的安全性能和循环寿命受到了极大的挑战。为此，各国研究机构对NCM811进行了大量研究以期提高其可应用性。
申请日为2016年8月11日的中国专利申请CN106058230A公布了一种铝掺杂与表面修饰共改性的高镍正极材料的制备方法，包括将高镍正极材料前驱体与铝盐溶胶混合，然后蒸干得到粉体，接着将粉体与锂盐混合烧结，得到高镍正极材料，该方法的优势在于通过湿法包覆提高了高镍正极材料前驱体与铝盐混合的均一性，但随后的蒸干能耗较高，而且通过该方法不能很好地降低高镍正极材料中的杂质锂含量，因而不利于改善电池的抗胀气性能。
申请日为2017年1月19日的中国专利申请CN107611384A公布了一种高性能浓度梯度高镍材料、其制备方法及在锂离子电池的用途，该方法首先制备镍含量由外而内逐渐增加的高镍前驱体，再与锂盐进行烧结得到高镍正极材料，该高镍正极材料具有较高的振实密度，但其没有改善高镍正极材料最关心的高温循环及胀气性能问题。
申请日为2016年12月22日的中国专利申请CN106602021A公布了一种包覆型锂离子电池正极材料及其制备方法，该方法是将金属盐溶于去离子水中，再加入正极物料进行搅拌、干燥、煅烧，提供一种可以在高镍正极材料表面形成均匀包覆层的包覆型锂离子电 池正极材料及其制备方法，合成出的材料杂锂含量较低，但其循环性能一般，50次循环后，容量从190mAh/g左右下降至140mAh/g左右，容量衰减较快。
发明内容
鉴于背景技术中存在的问题，本申请的目的在于提供一种正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置，所述正极活性材料具有高克容量、高结构稳定性以及高热稳定性的特点，能使电化学电池在具有高初始放电克容量的同时兼具优异的循环性能和存储性能。
为了达到上述目的，在本申请的第一方面，本申请提供了一种正极活性材料，其包括内核以及包覆层，所述包覆层包覆于所述内核的表面。所述内核选自分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料，掺杂元素M选自Zr、Ti、Te、Ca、Si中的一种或几种，掺杂元素M′选自Mg、Zn、Al、B、Ce、Fe中的一种或几种，掺杂元素Y选自F、Cl、Br中的一种或几种，-0.1≤a≤0.2、0≤d≤0.1、0.7≤x<1、0<y<0.3、0<z<0.3、0<b≤0.1、0<c≤0.1且x+y+z+b+c＝1，掺杂元素M、M′、Y各自在所述内核中的分布满足：从所述内核外侧到所述内核中心具有减小的质量浓度梯度。所述包覆层物质为包覆元素M″的氧化物，包覆元素M″选自Mg、Zn、Al、B、Ce、Fe中一种或几种。其中，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的质量比为1:(1～5)。
在本申请的第二方面，本申请提供了一种正极活性材料的制备方法，用于制备本申请第一方面所述的正极活性材料，其包括步骤：(1)将镍钴锰三元材料前驱体、含Li化合物、含M化合物、含M′化合物、含Y化合物置于混料设备中进行混料，然后置于气氛炉中进行一次烧结；(2)将步骤(1)一次烧结结束后的物料置于洗涤液中洗涤，然后离心、真空干燥，得到正极活性材料的内核，即分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料；(3)将正极活性材料的内核与含M″化合物置于混料设备中进行混料，然后置于气氛炉中进行二次烧结，形成正极活性材料的包覆层，完成正极活性材料的制备。
在本申请的第三方面，本申请提供了一种电化学电池，其包括本申请第一方面所述的正极活性材料。
在本申请的第四方面，本申请提供了一种电池模块，其包括本申请的第三方面所述的电化学电池。
在本申请的第五方面，本申请提供了一种电池包，其包括本申请的第四方面所述的电池模块。
在本申请的第六方面，本申请提供了一种装置，其包括本申请的第三方面所述的电化学电池，所述电化学电池用作所述装置的电源。
相对于现有技术，本申请的有益效果为：
本申请的正极活性材料包括内核和包覆于内核表面的包覆层，内核中对三元材料进行体相掺杂的元素M、M′、Y各自在内核中的元素分布满足从内核外侧到内核中心具有减小的质量浓度梯度，包覆层包括M″的氧化物，且包覆层中的包覆元素M″与内核中的掺杂元素M′的质量比为1:(1～5)，可以使正极活性材料具有高克容量、高结构稳定性以及高热稳定性的特点，进而使电化学电池在具有高初始放电克容量的同时兼具优异的循环性能和存储性能。
本申请的电池模块、电池包和装置包括所述的电化学电池，因而至少具有与所述电化学电池相同的优势。
附图说明
图1是电化学电池的一实施方式的立体图。
图2是图1的分解图。
图3是图2的电化学电池的电极组件的一实施方式的示意图，其中第一极片、第二极片以及隔离膜卷绕以形成卷绕式的电极组件。
图4是图2的电化学电池的电极组件的另一实施方式的示意图，其中第一极片、第二极片以及隔离膜沿厚度方向层叠以形成层叠式的电极组件。
图5是电池模块的一实施方式的立体图。
图6是电池包的一实施方式的立体图。
图7是图6的分解图。
图8是电化学电池作为电源的装置的一实施方式的示意图。
其中，附图标记说明如下：
1电池包
2上箱体
3下箱体
4电池模块
5电化学电池
51壳体
52电极组件
521第一极片
521a第一集流体
521b第一活性材料层
522第二极片
522a第二集流体
522b第二活性材料层
523隔离膜
524第一极耳
525第二极耳
53顶盖组件
具体实施方式
下面详细说明根据本申请的正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置。
首先说明根据本申请第一方面的正极活性材料，其包括内核以及包覆层，所述包覆层包覆于所述内核的表面。所述内核选自分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料，掺杂元素M选自Zr、Ti、Te、Ca、Si中的一种或几种，掺杂元素M′选自Mg、Zn、Al、B、Ce、Fe中的一种或几种，掺杂元素Y选自F、Cl、Br中的一种或几种，-0.1≤a≤0.2、0≤d≤0.1、0.7≤x<1、0<y<0.3、0<z<0.3、0<b≤0.1、0<c≤0.1且x+y+z+b+c＝1，掺杂元素M、M′、Y各自在所述内核中的分布满足：从所述内核外侧到所述内核中心具有减小的质量浓度梯度。所述包覆层物质为包覆元素M″的氧化物，包覆元素M″选自Mg、Zn、Al、B、Ce、Fe中一种或几种。其中，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的质量比为1:(1～5)。
电化学电池的初始放电克容量、循环性能以及存储性能与正极活性材料的物理性质和化学性质密切相关。在三元材料中，Ni、Co、Mn是同周期相邻的过渡金属元素，随着其比例的变化，三元材料的物理性质和化学性质会发生改变。通常认为，在三元材料中Ni是主要活性金属成分之一，并主要以+2价的形式存在，在脱嵌锂的过程中Ni 2+会被氧化为Ni 3+、Ni 4+，Co也是活性金属成分之一，并主要以+3价的形式存在，在脱嵌锂的过程 中Co 3+会被氧化为Co 4+，Mn呈现电化学惰性，并主要以+4价的形式存在，因此在电化学电池脱嵌锂的过程中，三元材料主要通过Ni和Co的价态变化来达到电荷平衡。
在三元材料中，Ni的含量越高，三元材料的克容量越大，越有利于提升电化学电池的初始放电克容量，但是Ni的含量较高时，Ni 2+与Li +容易发生混排。原因在于，Ni 2+与Li +的半径相近，在脱嵌锂的过程中，Ni 2+更容易迁移到Li +脱嵌形成的空位上，从而造成Li析出，在反复充放电过程中，Ni 2+与Li +的混排比例不断增加，三元材料的层状结构可能崩塌，这使得Li +在三元材料层状结构中的脱嵌越来越困难，最终导致电化学电池的循环性能恶化。同时，三元材料中Ni含量的增加还会降低三元材料的热分解温度，导致放热量增加，使三元材料的热稳定性变差。此外，三元材料中的Ni含量增加时，具有强氧化性的Ni 4+的含量也会增加，当电解液与三元材料接触时，电解液会与三元材料发生更多副反应，而为了保持电荷平衡，三元材料会释放出氧气，不仅会破坏三元材料的晶体结构，同时还会加速电化学电池的胀气，恶化电化学电池的存储性能。Co能有效稳定三元材料的层状结构并抑制锂镍混排，提高三元材料的电子导电性并改善电化学电池的循环性能，但是Co的成本较高。Mn的存在能够改善三元材料的结构稳定性和安全性能，并能够降低三元材料的成本，但是Mn的含量太高会出现尖晶石相而破坏三元材料的层状结构，使三元材料的克容量降低，并同时恶化电化学电池的循环性能。
从三元材料角度考虑，为了得到克容量高且成本低的三元材料，可以提高Ni的相对含量，同时降低Co、Mn的相对含量，此时三元材料可以具有较高的克容量，但结构稳定性较差。而从电化学电池角度考虑，提高Ni的相对含量，降低Co、Mn的相对含量可以增大电化学电池的初始放电克容量，但是会恶化循环性能和存储性能。
本申请的正极活性材料具有核壳结构，其中内核为体相掺杂的三元材料，其分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d，其中，Ni的相对含量较高，而Co、Mn的相对含量较低，因此正极活性材料可具有高克容量优势。但高Ni含量三元材料的热稳定性和结构稳定性不可避免地降低，由此不可避免的会使电化学电池的循环性能和存储性能发生恶化。
以M和M′为阳离子掺杂元素对内核的三元材料进行体相掺杂，可以显著地改善三元材料的热稳定性和结构稳定性。可能的原因在于，掺杂元素M、M′可以改变三元材料的晶格常数或三元材料中部分元素的价态，降低三元材料颗粒表面Ni 4+的相对含量，显著提高三元材料的热稳定性和结构稳定性，同时提高三元材料的电子电导率和离子电导率，减少三元材料中的锂镍混排，进而还能达到改善电化学电池循环性能的目的。以掺杂元素Al的体相掺杂为例，Al 3+可以抑制Ni 2+和Li +的混排，从而可以抑制充放电过程中三元材 料的相转变，提高三元材料的结构稳定性，并可以很好地改善电化学电池的循环性能。
进一步地，以Y为阴离子掺杂元素对内核的三元材料进行体相掺杂，掺杂元素Y可以取代部分O 2-，且由于掺杂元素Y为卤素，卤素与过渡金属(例如Ni、Co、Mn等)的化学键能要高于氧与过渡金属的化学键能，这有利于进一步增强三元材料的热稳定性和结构稳定性，同时还可缓解电解液中HF对三元材料的腐蚀。且优选地，掺杂元素Y为F。
此外，掺杂元素M、M′、Y在三元材料中呈现质量浓度递减的梯度分布方式还可以保证对三元材料的热稳定性和结构稳定性的改善更加连续和稳定。
以包覆元素M″的氧化物为包覆层物质对三元材料进行包覆，可以进一步防止三元材料与电解液直接接触，但不会阻碍锂离子正常的嵌入和脱嵌，由此可以显著地降低三元材料与电解液发生副反应而导致电解液氧化分解的概率，减少三元材料在充放电过程中为了平衡电荷而释放出的氧气量以及由此带来晶体结构崩塌的风险，同时包覆层对三元材料表面性能的改善，还能够减少充放电过程中的产热。此外，包覆层的存在还能够抑制三元材料的相变，进一步提高三元材料的结构稳定性。
如果仅是从三元材料中的Ni、Co、Mn、掺杂元素M、M′、Y以及包覆元素M″各自优化的角度考虑，对实现高克容量、高结构稳定性以及高热稳定性的正极活性材料存在很大的局限性。在本申请的正极活性材料设计中，将Ni、Co、Mn的含量，掺杂元素M、M′、Y的分布及含量，包覆元素M″的分布及含量综合起来考虑，当满足-0.1≤a≤0.2、0≤d≤0.1、0.7≤x<1、0<y<0.3、0<z<0.3、0<b≤0.1、0<c≤0.1且x+y+z+b+c＝1，同时包覆层中的包覆元素M″与内核中的掺杂元素M′的质量比为1:(1～5)时，正极活性材料可具有高克容量、高结构稳定性以及高热稳定性的特点，由此电化学电池可在具有高初始放电克容量的同时兼具优异的循环性能和存储性能。
优选地，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的质量比为1:(1～3)。
在本申请第一方面所述的正极活性材料中，优选地，从所述正极活性材料最外侧(即包覆层的外表面)向内核方向达到所述正极活性材料平均粒径1/5处的厚度范围内，M、M′、Y及M″的质量之和与所述正极活性材料中M、M′、Y及M″的总质量的比值大于50％，优选为55％以上。上述结构可以保证正极活性材料表层部分改性元素(包括掺杂元素M、M′、Y和包覆元素M″)的总含量不会过低，从而使正极活性材料具有高结构稳定性和高热稳定性的特点，进而电化学电池具有循环性能优良的特点。上述结构还可以保证正极活性材料中强氧化性镍的含量较低，从而可以减少正极活性材料(尤其是三元材料内核)与 电解液的副反应，起到很好地抑制产气的作用。此外，上述结构还可以保证获得的正极活性材料具有良好的电子电导率和离子电导率，由此使得电化学电池的直流阻抗还较低。
更优选地，从所述正极活性材料最外侧(即包覆层的外表面)向内核方向达到所述正极活性材料平均粒径2/3处的厚度范围内，M、M′、Y及M″的质量之和为所述正极活性材料中M、M′、Y及M″的总质量的90％以上，优选为93％以上。若掺杂元素M、M′、Y在内核中的扩散深度过深、或者径向浓度分布过宽，会导致对正极活性材料表层部分结构稳定性、热稳定性提高的改善效果不明显以及对强氧化性镍含量降低的改善效果不明显，同时还可能使正极活性材料颗粒内部的晶体结构畸变，影响其容量发挥。
在本申请第一方面所述的正极活性材料中，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的种类可以相同，也可以不同，并没有具体的限制，可根据实际需求进行选择。优选地，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的种类相同，这样更有利于锂离子的嵌入和脱嵌，进而更加有利于电化学电池性能的发挥。
在本申请第一方面所述的正极活性材料中，内核中掺杂元素M的质量浓度较小时，可能无法有效改善内核的热稳定性和结构稳定性，尤其是热稳定性的改善程度较弱，进而也无法有效改善电化学电池的循环性能；内核中掺杂元素M的质量浓度较大时，正极活性材料的克容量降低明显，对电化学电池的初始放电克容量不利。因此，优选地，以所述正极活性材料的总质量计算，所述内核中掺杂元素M的质量浓度为100ppm～3000ppm。
在本申请第一方面所述的正极活性材料中，内核中掺杂元素M′的质量浓度较小时，可能无法有效改善内核的热稳定性和结构稳定性，尤其是结构稳定性的改善程度较弱，进而也无法有效改善电化学电池的循环性能；内核中掺杂元素M′的质量浓度较大时，正极活性材料的克容量降低明显，对电化学电池的初始放电克容量不利。因此，优选地，以所述正极活性材料的总质量计算，所述内核中掺杂元素M′的质量浓度为100ppm～3000ppm。
在本申请第一方面所述的正极活性材料中，内核中掺杂元素Y的质量浓度较大时，正极活性材料的克容量降低明显，对电化学电池的初始放电克容量不利。因此，优选地，以所述正极活性材料的总质量计算，所述内核中掺杂元素Y的质量浓度为0～5000ppm。其中，所述内核中掺杂元素Y的质量浓度为0表示内核中也可以不掺杂元素Y。
在本申请第一方面所述的正极活性材料中，包覆层中包覆元素M″的质量浓度较小时，形成的包覆层通常较薄，可能无法有效防止内核与电解液的直接接触，从而无法充分起到抑制产气的效果；包覆层中包覆元素M″的质量浓度较大时，形成的包覆层较厚，在一定程度上会阻碍锂离子的嵌入和脱嵌，正极活性材料的克容量发挥较差，对电化学电池性能 影响较大。因此，优选地，以所述正极活性材料的总质量计算，所述包覆层中包覆元素M″的质量浓度为100ppm～3000ppm。
在本申请第一方面所述的正极活性材料中，包覆层厚度越大，对锂离子嵌入和脱嵌的阻碍就越大，正极活性材料的克容量发挥越差，对电化学电池性能的影响也就越大；包覆层的厚度越小，其包覆改性的效果就越不明显，可能无法有效防止内核与电解液的直接接触，从而无法充分起到抑制产气的效果。因此，优选地，所述包覆层的厚度T为0.001μm～0.5μm；更优选地，所述包覆层的厚度T为0.001μm～0.2μm。在上述优选范围内，正极活性材料可更好地兼具高克容量、高结构稳定性以及高热稳定性的特点，进而可更好地改善电化学电池的性能。
在本申请第一方面所述的正极活性材料中，优选地，所述正极活性材料的平均粒径D50为8μm～20μm。在上述优选范围内时，正极极片的均一性可更高，既可以避免粒径太小与电解液产生较多的副反应而影响电化学电池的性能，还可以避免粒径太大阻碍锂离子在颗粒内部传输而影响电化学电池的性能。
在本申请第一方面所述的正极活性材料中，进一步优选地，所述包覆层的厚度T与所述正极活性材料的平均粒径D50满足：0.005≤T/D50≤0.02。
在本申请第一方面所述的正极活性材料中，优选地，所述正极活性材料中杂质锂浓度小于等于1500ppm；更优选地，所述正极活性材料中杂质锂浓度为700ppm～1500ppm。正极活性材料中的杂质锂主要包括氢氧化锂、碳酸锂形式的碱性锂化合物，这些杂质锂的存在不仅会对正极极片的加工性能产生影响，还会对电化学电池的高温性能和安全性能产生影响。可能的原因在于：首先，杂质锂以碱性锂化合物为主，当正极活性材料中杂质锂的含量升高时，正极活性材料的pH值也会升高，在少量水的存在下就会使正极浆料粘稠甚至变为凝胶状，从而影响正极极片的加工性能；其次，在高温条件下杂质锂会发生分解，使电化学电池胀气，恶化了电化学电池的高温性能和安全性能。本申请的正极活性材料为核壳结构，内核三元材料经过掺杂元素掺杂(包括阳离子掺杂或阳离子与阴离子混合掺杂)，正极活性材料可具有热稳定性和结构稳定性高的特点，可以在一定程度上降低正极活性材料的杂质锂含量；另外，包覆层的存在也可以在一定程度上降低正极活性材料的杂质锂含量。因此本申请的正极活性材料可具有较低的杂质锂浓度，进而可保证正极极片具有更好的加工性能，保证电化学电池具有更好的高温性能和安全性能。
其次说明根据本申请第二方面的正极活性材料的一种制备方法，用于制备本申请第一 方面所述的正极活性材料，包括步骤：
(1)将镍钴锰三元材料前驱体、含Li化合物、含M化合物、含M′化合物、含Y化合物置于混料设备中进行混料，然后置于气氛炉中进行一次烧结；
(2)将步骤(1)一次烧结结束后的物料置于洗涤液中洗涤，然后离心、真空干燥，得到正极活性材料的内核，即分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料；
(3)将正极活性材料的内核与含M″化合物置于混料设备中进行混料，然后置于气氛炉中进行二次烧结，形成正极活性材料的包覆层，完成正极活性材料的制备。
在本申请第二方面的制备方法中，将镍钴锰三元材料前驱体、含Li化合物、含M化合物、含M′化合物、含Y化合物一次烧结可以得到掺杂元素M、M′、Y从颗粒表面到颗粒内部具有减小的质量浓度梯度的三元材料；采用洗涤液对三元材料进行洗涤可以显著地降低三元材料表面的杂质锂含量；将洗涤干燥后的三元材料与含M″化合物二次烧结可以得到M″氧化物包覆以及M、M′、Y体相掺杂的正极活性材料。
步骤(1)中，镍钴锰三元材料前驱体可以为镍钴锰氧化物，也可以为镍钴锰氢氧化物，其中镍钴锰氧化物和镍钴锰氢氧化物可以通过常规的二次干燥法或共沉淀法合成。
步骤(1)中，含Li化合物的种类没有具体的限制，可根据实际需求进行选择。优选地，含锂化合物可以为氢氧化锂、碳酸锂、硝酸锂等。
步骤(1)中，含M化合物、含M′化合物的种类也没有具体的限制，可根据实际需求进行选择。优选地，含M化合物可选自M的氧化物、M的氯化物、M的硫酸盐、M的硝酸盐、M的碳酸盐、M的碳酸氢盐等；含M′化合物可选自M′的氧化物、M′的氯化物、M′的硫酸盐、M′的硝酸盐、M′的碳酸盐、M′的碳酸氢盐等。
步骤(1)中，含Y化合物的种类也没有具体的限制，可根据实际需求进行选择。优选地，含Y化合物可选自Y的铵盐或Y的锂盐，例如可为NH 4F、NH 4Cl、NH 4Br、LiF、LiCl、LiBr等。
步骤(1)中，混料时间没有具体的限制，可根据实际需求进行选择，只要将镍钴锰三元材料前驱体、含Li化合物、含M化合物、含M′化合物、含Y化合物混合均匀即可。优选地，混料时间为0.5h～3h。
步骤(1)中，气氛炉中一次烧结气氛可为空气或氧气；优选地，一次烧结气氛为氧气；更优选地，气氛炉中氧气浓度为50％～100％；更进一步优选地，气氛炉中氧气浓度为80％～100％。
步骤(1)中，优选地，一次烧结温度为700℃～950℃。
步骤(1)中，优选地，一次烧结时间为5h～25h；更优选地，一次烧结时间为10h～20h。
步骤(2)中，洗涤液可以为去离子水也可以为含硼化合物溶液。其中，含硼化合物溶液中的溶剂可为去离子水、乙醇或两者的混合溶剂，溶质含硼化合物可选自B 2O 3、H 3BO 3、C 6H 5B(OH) 2、C 3H 9B 3O 6、(C 3H 7O) 3B中的一种或几种。优选地，所述含硼化合物溶液的浓度可为0.01mol/L～1mol/L。
步骤(2)中，优选地，洗涤温度为10℃～50℃；更优选地，洗涤温度为20℃～40℃。优选地，洗涤时间为1min～60min；更优选地，洗涤时间为2min～30min。优选地，洗涤时搅拌速度为10r/min～500r/min；更优选地，洗涤时搅拌速度为20r/min～200r/min。
步骤(2)中，为了达到更好的洗涤效果，优选地，一次烧结结束后的物料与洗涤液的质量比为1:(0.5～10)；更优选地，一次烧结结束后的物料与洗涤液的质量比为1:(1～5)。
步骤(2)中，优选地，真空干燥的温度为80℃～150℃；更优选地，真空干燥的温度为90℃～120℃。优选地，真空干燥的时间为2h～20h；更优选地，真空干燥的时间为5h～10h。
步骤(3)中，含M″化合物的种类没有具体的限制，可根据实际需求进行选择。优选地，含M″化合物可选自M″的氧化物、M″的氯化物、M″的硫酸盐、M″的硝酸盐、M″的碳酸盐、M″的碳酸氢盐等。
步骤(3)中，混料时间没有具体的限制，可根据实际需求进行选择，只要将正极活性材料的内核和含M″化合物混合均匀即可。优选地，混料时间为0.5h～3h。
步骤(3)中，气氛炉中二次烧结气氛可为空气或氧气，优选地，二次烧结气氛为氧气；更优选地，气氛炉中氧气浓度为50％～100％；更进一步优选地，气氛炉中氧气浓度为80％～100％。
步骤(3)中，优选地，二次烧结温度为200℃～500℃。
步骤(3)中，优选地，二次烧结时间为5h～25h；更优选地，二次烧结时间为5h～10h。
需要注意的是，在上述步骤(1)和步骤(3)中，含M′化合物与含M″化合物的种类可以相同，也可以不同，可根据实际需求进行选择。优选地，步骤(1)中含M′化合物与步骤(3)中含M″化合物的种类相同。
再次说明根据本申请第三方面的电化学电池。
图1是电化学电池5的一实施方式的立体图。图2是图1的分解图。图3是图2的电化学电池5的电极组件52的一实施方式的示意图，其中第一极片521、第二极片522以及隔离膜523卷绕以形成卷绕式的电极组件。图4是图2的电化学电池5的电极组件52 的另一实施方式的示意图，其中第一极片521、第二极片522以及隔离膜523沿厚度方向层叠以形成层叠式的电极组件。
参照图1至图4，电化学电池5包括壳体51、电极组件52、顶盖组件53以及电解液(未示出)。
电极组件52收容于壳体51内。电极组件52包括第一极片521、第二极片522、隔离膜523、第一极耳524以及第二极耳525。隔离膜523将第一极片521和第二极片522隔开。
第一极片521包括第一集流体521a以及设置在第一集流体521a的表面上的第一活性材料层521b。第一活性材料层521b含有第一活性材料。第一活性材料层521b可以依据实际需要设置在第一集流体521a的一个表面或两个表面上。第二极片522包括第二集流体522a以及设置在第二集流体522a的表面上的第二活性材料层522b。第二活性材料层522b可以依据实际需要设置在第二集流体522a的一个表面或两个表面上。第二活性材料层522b含有第二活性材料。第一活性材料和第二活性材料实现活性离子(例如针对锂离子电池为锂离子)的脱嵌。第一极片521和第二极片522电性相反，即第一极片521和第二极片522中的一个为正极片而第一极片521和第二极片522中的另一个为负极片。其中，第一极耳524可以通过裁切第一集流体521a形成或者单独形成并固定连接于第一集流体521a。同样地，第二极耳525可以通过裁切第二集流体522a形成或者单独形成并固定连接于第二集流体522a。
电极组件52的数量不受限制，可以为一个或多个。
电解液注入在壳体51内并浸渍电极组件51，具体地浸渍第一极片521、第二极片522以及隔离膜523。
注意的是图1所示的电化学电池5为罐型电池，但不限于此，电化学电池5可以是袋型电池，即壳体51由金属塑膜替代且取消顶盖组件53。
在电化学电池5中，由于第一极片521和第二极片522中的一个为正极片，故正极片的集流体为正极集流体、正极片的活性材料层为正极活性材料层，正极片的活性材料为正极活性材料。由此，所述正极片包括正极集流体和设置于正极集流体上的正极活性材料层，所述正极活性材料层包括本申请第一方面所述的正极活性材料。在本申请第三方面的电化学电池中，所述隔离膜的种类并不受到具体的限制，可以是现有电化学电池中使用的任何隔离膜材料，例如聚乙烯、聚丙烯、聚偏氟乙烯以及它们的多层复合膜，但不仅限于这些。
在本申请第三方面的电化学电池中，所述电解液的具体种类及组成均不受到具体的限 制，可根据实际需求进行选择。
需要说明的是，所述电化学电池可为锂离子电池、金属锂电池、全固态锂电池或超级电容器。在本申请的实施例中，仅示出电化学电池为锂离子电池的实施例，但本申请不限于此。
接下来说明本申请第四方面的电池模块。
图5是电池模块4的一实施方式的立体图。参照图5，电池模块4包括多个电化学电池5。多个电化学电池5沿纵向排列。电池模块4可以作为电源或储能装置。
本申请第四方面提供的一种电池模块4，其包括本申请的第三方面所述的电化学电池5。包括在电池模块4中的电化学电池5的数量可以根据电池模块4的应用和容量进行调节。
接下了说明本申请第五方面的电池包。
图6是电池包1的一实施方式的立体图。图7是图6的分解图。
参照图6和图7，电池包1包括上箱体2、下箱体3以及电池模块4。上箱体2和下箱体3组装在一起并形成收容电池模块4的空间。电池模块4置于组装在一起的上箱体2和下箱体3的空间内。电池模块4的输出极从上箱体2和下箱体3的其中之一或二者之间穿出，以向外部供电或从外部充电。电池包1采用的电池模块4的数量和排列可以依据实际需要来确定。电池包1可以作为电源或储能装置。
本申请第五方面提供的电池包，其包括本申请的第四方面所述的电池模块4。
图8是电化学电池作为电源的装置的一实施方式的示意图。
本申请第六方面提供的装置，包括本申请的第三方面所述的电化学电池5，所述电化学电池用作所述装置的电源。在图8中，采用电化学电池5的装置为电动汽车。所述电化学电池5可以用作所述装置的电源。当然不限于此，采用电化学电池5的装置可以为除电动汽车外的任何电动车辆(例如电动大巴、电动有轨电车、电动自行车、电动摩托车、电动踏板车、电动高尔夫球车、电动卡车)、电动船舶、电动工具、电子设备及储能系统。电动汽车可以为电动纯电动车、混合动力电动车、插电式混合动力电动车。当然，依据实际使用形式，本申请第六方面提供的装置可包括本申请的第四方面所述的电池模块4，当然，本申请第六方面提供的装置也可包括本申请的第五方面所述的电池包1。
下面以锂离子电池为例，结合实施例，进一步阐述本申请。应理解，这些实施例仅用于说明本申请而不用于限制本申请的范围。
实施例1
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为100ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为1500ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为2160ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为3348ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例2
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为1500ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为3000ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为4650ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例3
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为3000ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为1500ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为3900ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的含量之和为6045ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例4
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质 量浓度为100ppm，包覆层中M″元素的质量浓度为100ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为1020ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为1581ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例5
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为1500ppm，包覆层中M″元素的质量浓度为1500ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、 三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为2700ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为4185ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例6
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为3000ppm，包覆层中M″元素的质量浓度为3000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗 涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为4500ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为6975ppm，Ti元素和Al元素的质量占正极活性材料中Ti元素和Al元素的总质量的比例w 2为93％。
实施例7
(1)原料准备
三元材料前躯体为[Ni 0.70Co 0.15Mn 0.15](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化锆(ZrO 2)
含M′化合物为三氧化二硼(B 2O 3)
含M″化合物为三氧化二硼(B 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为1000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.70Co 0.15Mn 0.15](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化锆(ZrO 2)、三氧化二硼(B 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为850℃，一次烧结时间为20h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与B 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为500℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Zr元素和B元素的质量浓度之和为2475ppm，Zr元素和B元素的质量占正极活性材料中Zr元素和B元素的总质量的比例w 1为55％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Zr元素和B元素的质量浓度之和为4095ppm，Zr元素和B元素的质量占正极活性材料中Zr元素和B元素的总质量的比例w 2为91％。
实施例8
(1)原料准备
三元材料前躯体为[Ni 0.85Co 0.10Mn 0.05](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为氧化钙(CaO)
含M′化合物为氧化镁(MgO)
含M″化合物为氧化镁(MgO)
以上述原料总质量计算，内核中M元素的质量浓度为2000ppm，内核中M′元素的质量浓度为3000ppm，包覆层中M″元素的质量浓度为1000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.85Co 0.10Mn 0.05](OH) 2、氢氧化锂(LiOH·H 2O)、氧化钙(CaO)、氧化镁(MgO)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为750℃，一次烧结时间为20h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与MgO置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为200℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ca元素和Mg元素的质量浓度之和为4320ppm，Ca元素和Mg元素的质量占正极活性材料中Ca元素和Mg元素的总质量的比例w 1为72％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ca元素和Mg元素的质量浓度之和为5820ppm，Ca元素和Mg元素的质量占正极活性材料中Ca元素和Mg元素的总质量的比例w 2为97％。
实施例9
(1)原料准备
三元材料前躯体为[Ni 0.85Co 0.10Mn 0.05](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为氧化钙(CaO)
含M′化合物为三氧化二硼(B 2O 3)、三氧化二铝(Al 2O 3)混合物
含M″化合物为三氧化二硼(B 2O 3)、三氧化二铝(Al 2O 3)混合物
以上述原料总质量计算，内核中M元素的质量浓度为2000ppm，内核中M′元素的质量浓度为3000ppm，包覆层中M″元素的质量浓度为1000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.85Co 0.10Mn 0.05](OH) 2、氢氧化锂(LiOH·H 2O)、氧化钙(CaO)、三氧化二硼(B 2O 3)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为800℃，一次烧结时间为10h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与B 2O 3、Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为200℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ca元素、B元素和Al元素的质量浓度之和为3840ppm， Ca元素、B元素和Al元素的质量占正极活性材料中Ca元素、B元素和Al元素的总质量的比例w 1为64％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ca元素、B元素和Al元素的质量浓度之和为5700ppm，Ca元素、B元素和Al元素的质量占正极活性材料中Ca元素、B元素和Al元素的总质量的比例w 2为95％。
实施例10
(1)原料准备
三元材料前躯体为[Ni 0.85Co 0.10Mn 0.05](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二硼(B 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为2500ppm，内核中M′元素的质量浓度为2400ppm，包覆层中M″元素的质量浓度为1200ppm。
(2)制备过程
将三元材料前躯体[Ni 0.85Co 0.10Mn 0.05](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料2h后，置于O 2浓度为80％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为800℃，一次烧结时间为10h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:0.5，洗涤温度为40℃，洗涤时间为10min，洗涤时搅拌速度为100rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于120℃的真空干燥箱中烘干5h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与B 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为80％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为400℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素、B元素的质量浓度之和为3904ppm，Ti元素、Al元素、B元素的质量占正极活性材料中Ti元素、Al元素、B元素的总质量的比例w 1为64％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的 厚度范围内，Ti元素、Al元素、B元素的质量浓度之和为5795ppm，Ti元素、Al元素、B元素的质量占正极活性材料中Ti元素、Al元素、B元素的总质量的比例w 2为95％。
实施例11
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.10Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为2000ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为400ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.10Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料0.5h后，置于O 2浓度为100％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为900℃，一次烧结时间为15h。
将一次烧结结束后的物料置于1mol/L的C 5H 6B(OH) 2的乙醇与水混合溶液中进行洗涤，其中，物料与洗涤液的质量比为1:5，洗涤温度为30℃，洗涤时间为2min，洗涤时搅拌速度为20rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于120℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机进行混料，混料0.5h后，置于O 2浓度为100％的气氛烧结炉中进行二次烧结，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素的质量浓度之和为2200ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为50％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素、Al元素的质量浓度之和为4180ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为95％。
实施例12
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为100ppm，内核中M′元素的质量浓度为3000ppm，包覆层中M″元素的质量浓度为3000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料0.5h后，置于O 2浓度为100％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为900℃，一次烧结时间为15h。
将烧结结束后的物料置于0.8mol/L的(C 3H 7O) 3B乙醇溶液中进行洗涤，其中，物料与洗涤液的质量比为1:3，洗涤温度为35℃，洗涤时间为3min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料1.5h后，置于O 2浓度为100％的气氛烧结炉中进行二次烧结，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素的质量浓度之和为3660ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为60％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素、Al元素的质量浓度之和为4880ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为80％。
实施例13
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
含Y化合物为NH 4F。
以上述原料总质量计算，内核中M元素的质量浓度为100ppm，内核中M′元素的质量浓度为2000ppm，Y元素的质量浓度为1000ppm，包覆层中M″元素的质量浓度为600ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)、氟化氨(NH 4F)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素、F元素的质量浓度之和为2331ppm，Ti元素、Al元素、F元素的质量占正极活性材料中Ti元素、Al元素、F元素的总质量的比例w 1为63％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素、Al元素、F元素的质量浓度之和为3367ppm，Ti元素、Al元素、F元素的质量占正极活性材料中Ti元素、Al元素、F元素的总质量的比例w 2为91％。
对比例1
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
以上述原料总质量计算，M元素的质量浓度为50ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行烧结，其中，烧结温度为830℃，烧结时间为15h，烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素的质量占正极活性材料中Ti元素的总质量的比例w 1为45％；从正极活性材料最外侧达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素的质量占正极活性材料中Ti元素的总质量的比例w 2为94％。
对比例2
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，M元素的质量浓度为2000ppm，M′元素的质量浓度为2000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料0.5h后，置于O 2浓度为100％的气氛烧结炉中进行烧结，其中，烧结温度为830℃，烧结时间为15h，烧结结束后得到体相掺杂的三元材料，即正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为45％；从正极活性材料最外侧达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为94％。
对比例3
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，包覆层中M″元素的质量浓度为2000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
取一次烧结结束后的物料与Al 2O 3置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结，其中，二次烧结温度为650℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Al元素的质量占正极活性材料中Al元素的总质量的比例w 1为94％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Al元素的质量占正极活性材料中Al元素的总质量的比例w 2为98％。
对比例4
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为5000ppm，包覆层中M″元素的质量浓度为1000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)二氧化钛(TiO 2)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次 烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
取一次烧结结束后的物料与Al 2O 3置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结，其中，二次烧结温度为650℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为56％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为96％。
对比例5
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为4800ppm，包覆层中M″元素的质量浓度为800ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为3053ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为43％；从正极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为6887ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为97％。
对比例6
(1)原料准备
三元材料前躯体为[Ni 0.8Co 0.1Mn 0.1](OH) 2，质量为4300g
含Li化合物为氢氧化锂(LiOH·H 2O)，质量为2035g
含M化合物为二氧化钛(TiO 2)
含M′化合物为三氧化二铝(Al 2O 3)
含M″化合物为三氧化二铝(Al 2O 3)
以上述原料总质量计算，内核中M元素的质量浓度为1500ppm，内核中M′元素的质量浓度为2000ppm，包覆层中M″元素的质量浓度为4000ppm。
(2)制备过程
将三元材料前躯体[Ni 0.8Co 0.1Mn 0.1](OH) 2、氢氧化锂(LiOH·H 2O)、二氧化钛(TiO 2)、三氧化二铝(Al 2O 3)置于高速混料机中进行混料，混料1h后，置于O 2浓度为90％的气氛烧结炉中进行一次烧结，其中，一次烧结温度为830℃，一次烧结时间为15h。
将一次烧结结束后的物料置于0.05mol/L的硼酸水溶液中进行洗涤，其中，物料与洗涤液的质量比为1:2，洗涤温度为20℃，洗涤时间为5min，洗涤时搅拌速度为200rpm；洗涤完成后进行离心分离，然后将离心后的固体物料置于100℃的真空干燥箱中烘干10h，得到体相掺杂的三元材料，即正极活性材料的内核。
将体相掺杂的三元材料与Al 2O 3置于高速混料机中进行混料，混料2h后，置于O 2浓度为90％的气氛烧结炉中进行二次烧结形成正极活性材料的包覆层，其中，二次烧结温度为250℃，二次烧结时间为5h，二次烧结结束后即得到所需的正极活性材料。
其中，在所得到的正极活性材料中：从正极活性材料最外侧向内核方向达到正极活性材料平均粒径1/5处的厚度范围内，Ti元素和Al元素的质量浓度之和为4875ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 1为65％；从正 极活性材料最外侧向内核方向达到正极活性材料平均粒径2/3处的厚度范围内，Ti元素和Al元素的质量浓度之和为7125ppm，Ti元素、Al元素的质量占正极活性材料中Ti元素、Al元素的总质量的比例w 2为95％。
接下来说明正极活性材料的测试过程。
(1)正极活性材料中杂质锂含量测试
采用酸碱滴定法测试正极活性材料中杂质锂含量。将30g实施例和对比例制备的正极活性材料样品放入100ml纯水中，搅拌30min后静置5min，抽滤后取10ml上清液，用0.05mol/L的盐酸标准溶液滴定正极活性材料样品中溶解下来的碳酸锂和氢氧化锂，以pH电极为指示电极，借助于电位变化产生的突跃来确定终点，并计算正极活性材料中的杂质锂含量。
(2)正极活性材料克容量测试
将实施例和对比例制备的正极活性材料、导电剂乙炔黑、粘结剂聚偏二氟乙烯(PVDF)按质量比90:5:5进行混合，加入溶剂N-甲基吡咯烷酮(NMP)，在干燥房搅拌至体系呈均一状，获得正极浆料；将正极浆料均匀涂覆在正极集流体铝箔上，烘干、冷压制成正极片。
将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸二甲酯(DMC)按体积比1:1:1进行混合得到有机溶剂，接着将充分干燥的LiPF 6溶解于混合后的有机溶剂中，配制成浓度为1mol/L的电解液。
以锂片作为负极片，与制备好的正极片组装成标准扣式电池。
在2.8V～4.25V电压下，将纽扣电池以0.1C恒流充电至4.25V，然后以4.25V恒压充电至电流≤0.05mA，静置2min，此时的充电容量记为C 0；然后以0.1C恒流放电至2.8V，此时的放电容量为记为D 0。
放电容量D 0与正极活性材料质量的比值即为正极活性材料的克容量。
正极活性材料的首次库伦效率(％)＝D 0/C 0×100％。
接下来说明正极活性材料在全电池(即锂离子电池)中的性能表现。
首先将实施例和对比例制备的正极活性材料按照下述方法组装成锂离子电池。
(1)正极片的制备：将实施例和对比例制备的正极活性材料、导电剂乙炔黑、粘结剂聚偏二氟乙烯(PVDF)按质量比94:3:3进行混合，加入溶剂N-甲基吡咯烷酮(NMP)， 在真空搅拌机作用下搅拌至体系呈均一状，获得正极浆料；将正极浆料均匀涂覆在正极集流体铝箔的两个表面上，室温晾干后转移至烘箱继续干燥，然后经过冷压、分切得到正极片。
(2)负极片的制备：将负极活性材料人造石墨以及硬碳、导电剂乙炔黑、粘结剂丁苯橡胶(SBR)、增稠剂羧甲基纤维素钠(CMC)按质量比90:5:2:2:1进行混合，加入溶剂去离子水，在真空搅拌机作用下搅拌至体系呈均一状，获得负极浆料；将负极浆料均匀涂覆在负极集流体铜箔的两个表面上，室温晾干后转移至烘箱继续干燥，然后经过冷压、分切得到负极极片。
(3)电解液的制备：将碳酸乙烯酯(EC)、碳酸二乙酯(DEC)和碳酸二甲酯(DMC)按体积比1:1:1进行混合得到有机溶剂，接着将充分干燥的LiPF 6溶解于混合后的有机溶剂中，配制成浓度为1mol/L的电解液。
(4)隔离膜的制备：以聚乙烯(PE)膜作为隔离膜。
(5)锂离子电池的制备：将正极极片、隔离膜、负极极片按顺序叠好，使隔离膜处于正、负极极片之间起到隔离的作用，然后卷绕得到裸电芯；将裸电芯置于外包装壳中，干燥后注入电解液，经过真空封装、静置、化成、整形等工序，获得锂离子电池。
下面说明锂离子电池的测试过程。
(1)锂离子电池的初始放电克容量测试
在25℃恒温环境下，将锂离子电池静置5min，然后以1/3C恒流放电至2.8V，静置5min，再以1/3C恒流充电至4.25V，接着以4.25V恒压充电至电流≤0.05mA，静置5min，此时的充电容量记为C 0；然后以1/3C恒流放电至2.8V，此时的放电容量记为D 0。
放电容量D 1与正极活性材料质量的比值即为锂离子电池的初始克容量。
锂离子电池的首次库伦效率(％)＝D 0/C 0×100％。
(2)锂离子电池的常温循环性能测试
在25℃的恒温环境下，将锂离子电池以1C恒流充电至4.25V，接着以4.25V恒压充电至电流≤0.05mA，静置5min，然后以1C恒流放电至2.8V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。然后将锂离子电池按照上述方法进行1200次循环充电/放电测试，检测得到第1200次循环的放电容量。
锂离子电池25℃循环1200次后的容量保持率(％)＝(第1200次循环的放电容量/首次循环的放电容量)×100％。
(3)锂离子电池的高温循环性能测试
在45℃的恒温环境下，将锂离子电池以1C恒流充电至4.25V，接着以4.25V恒压充电至电流≤0.05mA，静置5min，然后以1C恒流放电至2.8V，此为一个充放电循环过程，此次的放电容量为首次循环的放电容量。然后将锂离子电池按照上述方法进行800次循环充电/放电测试，检测得到第800次循环的放电容量。
锂离子电池45℃循环800次后的容量保持率(％)＝(第800次循环的放电容量/首次循环的放电容量)×100％。
(4)锂离子电池的高温存储性能测试
首先在25℃下将锂离子电池满充，采用排水法测试满充锂离子电池的体积，并记为V 1；然后将锂离子电池置于80℃条件下进行存储，每48h取出，静置并冷却至室温后采用排水法测试锂离子电池的体积，直至存储满10天结束测试，锂离子电池存储结束后的体积记为V 10。
锂离子电池在80℃下存储10天后的体积膨胀率(％)＝(V 10/V 1-1)×100％。
表1：实施例1-13和对比例1-6的测试结果
Figure PCTCN2019107909-appb-000001
Figure PCTCN2019107909-appb-000002
从表1的测试结果分析可知，对比例1-4制备的正极活性材料普遍存在杂质锂含量高、克容量低的问题，锂离子电池普遍存在初始放电克容量低、常温和高温循环性能差、高温存储性能差的问题。
其中，对比例1的正极活性材料仅体相掺杂了少量的Ti元素且无包覆层，正极活性材料的杂质锂含量高且克容量低，同时锂离子电池的常温循环性能、高温循环性能和高温存储性能均很差。
对比例2的正极活性材料同时掺杂了Ti元素和Al元素，但也无包覆层，与对比例1相比，正极活性材料的杂质锂含量有所降低，同时正极活性材料的克容量和锂离子电池的初始放电克容量有所提升，锂离子电池的常温循环性能、高温循环性能和高温存储性能也有一定改善，但改善程度有限。可能的原因在于，正极活性材料中强氧化镍含量依旧较高，电解液与正极活性材料之间存在较多的副反应，因此锂离子电池胀气现象依旧严重。
对比例3的正极活性材料仅含有包覆层，与对比例1相比，正极活性材料的杂质锂含量有所降低，同时正极活性材料的克容量和锂离子电池的初始放电克容量有所提升，锂离子电池的常温循环性能、高温循环性能和高温存储性能也有一定改善，但改善程度有限。可能的原因在于，正极活性材料的三元材料内核具有较差的热稳定性和结构稳定性，在高温环境中以及反复充放电过程中，由于Ni 2+与Li +的混排比例不断增加，三元材料的层状结构可能崩塌，进而使锂离子电池的性能尤其是循环性能依旧较差。
对比例4的正极活性材料体相掺杂了较高含量的Ti元素，且表面还包覆了Al 2O 3，与对比例1相比，正极活性材料的杂质锂含量有所降低，同时锂离子电池的常温循环性能、高温循环性能和高温存储性能略有改善，但改善程度有限。可能的原因在于，正极活性材料的三元材料内核具有较差的结构稳定性，在锂离子电池反复充放电过程中，由于Ni 2+与Li +的混排比例不断增加，三元材料内核的层状结构可能崩塌，进而使锂离子电池的性能尤其是循环性能依旧较差。
在实施例1-13中，正极活性材料同时经过掺杂元素M、M′、Y的体相掺杂以及包覆元素M″的氧化物包覆，正极活性材料可具有高克容量、高结构稳定性以及高热稳定性的特点，同时正极活性材料的杂质锂含量较低，可以使锂离子电池在具有高初始放电克容量的同时兼具优异的常温和高温循环性能以及高温存储性能。
在对比例5中，尽管正极活性材料同时经过掺杂元素Ti和Al的体相掺杂以及Al 2O 3包覆，但包覆层中的Al与体相掺杂的Al的质量比为1:6，即包覆层中Al元素含量过少，难以保证正极活性材料表层部分具有高结构稳定性和高热稳定性的特点。
在对比例6中，尽管正极活性材料同时经过掺杂元素Ti和Al的体相掺杂以及Al 2O 3包覆，但包覆层中的Al与体相掺杂的Al的质量比为1:0.5，即包覆层中Al元素含量过高，包覆层对锂离子嵌入和脱嵌的阻碍作用过大，影响了正极活性材料的克容量发挥，进而影响了锂离子电池的性能。

Claims (15)

  1. 一种正极活性材料，包括：
    内核；以及
    包覆层，包覆于所述内核的表面；
    其特征在于，
    所述内核选自分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料，其中，掺杂元素M选自Zr、Ti、Te、Sb、Ca、Si中的一种或几种，掺杂元素M′选自Mg、Zn、Al、B、Ce、Fe中的一种或几种，掺杂元素Y选自F、Cl、Br中的一种或几种，-0.1≤a≤0.2、0≤d≤0.1、0.7≤x<1、0<y<0.3、0<z<0.3、0<b≤0.1、0<c≤0.1且x+y+z+b+c＝1，掺杂元素M、M′、Y各自在所述内核中的分布满足：从所述内核外侧到所述内核中心具有减小的质量浓度梯度；
    所述包覆层物质为包覆元素M″的氧化物，且M″选自Mg、Zn、Al、B、Ce、Fe中一种或几种；
    所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′的质量比为1:(1～5)，优选为1:(1～3)。
  2. 根据权利要求1所述的正极活性材料，其特征在于，从所述正极活性材料最外侧向内核方向达到所述正极活性材料平均粒径1/5处的厚度范围内，M、M′、Y及M″的质量之和与所述正极活性材料中M、M′、Y及M″的总质量的比值大于50％，优选为55％以上。
  3. 根据权利要求2所述的正极活性材料，其特征在于，从所述正极活性材料的最外侧向内核方向达到所述正极活性材料平均粒径2/3处的厚度范围内，M、M′、Y及M″的质量之和为所述正极活性材料中M、M′、Y及M″的总质量90％以上，优选为93％以上。
  4. 根据权利要求1-3中任一项所述的正极活性材料，其特征在于，所述包覆层中的包覆元素M″与所述内核中的掺杂元素M′相同。
  5. 根据权利要求1所述的正极活性材料，其特征在于，以所述正极活性材料的总质量计算，
    所述内核中掺杂元素M的质量浓度为100ppm～3000ppm；
    所述内核中掺杂元素M′的质量浓度为100ppm～3000ppm；
    所述内核中掺杂元素Y的质量浓度为0～5000ppm；
    所述包覆层中包覆元素M″的质量浓度为100ppm～3000ppm。
  6. 根据权要求1所述的正极活性材料，其特征在于，
    所述正极活性材料的平均粒径D50为8μm～20μm，所述包覆层的厚度T为0.001μm～0.5μm；
    优选地，0.005≤T/D50≤0.02。
  7. 根据权利要求1所述的正极活性材料，其特征在于，所述正极活性材料中含有杂质锂，所述杂质锂包括氢氧化锂和碳酸锂，且所述杂质锂的浓度小于等于1500ppm。
  8. 一种正极活性材料的制备方法，用于制备权利要求1-7中任一项所述的正极活性材料，其特征在于，包括步骤：
    (1)将镍钴锰三元材料前驱体、含Li化合物、含M化合物、含M′化合物、含Y化合物置于混料设备中进行混料，然后置于气氛炉中进行一次烧结；
    (2)将步骤(1)一次烧结结束后的物料置于洗涤液中洗涤，然后离心、真空干燥，得到正极活性材料的内核，即分子式为Li 1+a[Ni xCo yMn zM bM′ c]O 2-dY d的三元材料；
    (3)将正极活性材料的内核与含M″化合物置于混料设备中进行混料，然后置于气氛炉中进行二次烧结，形成正极活性材料的包覆层，完成正极活性材料的制备。
  9. 根据权利要求8所述的正极活性材料的制备方法，其特征在于，
    在步骤(1)中，一次烧结的温度为700℃～950℃；
    在步骤(3)中，二次烧结的温度为200℃～500℃。
  10. 根据权利要求8所述的正极活性材料的制备方法，其特征在于，在步骤(2)中，所述一次烧结结束后的物料与所述洗涤液的质量比为1:(0.5～10)，优选为1:(1～5)。
  11. 一种电化学电池，其特征在于，包括根据权利要求1-7中任一项所述的正极活性 材料。
  12. 一种电池模块，其特征在于，包括根据权利要求11所述的电化学电池作为单元电池。
  13. 一种电池包，其特征在于，包括根据权利要求12所述的电池模块。
  14. 一种装置，其特征在于，包括根据权利要求11所述的电化学电池，所述电化学电池作为所述装置的电源。
  15. 根据权利要求14所述的装置，其特征在于，所述装置包括电动车辆、混合动力电动车辆、插电式混合动力电动车辆、电动自行车、电动踏板车、电动高尔夫球车、电动卡车、电动船舶、储能系统。
PCT/CN2019/107909 2018-09-26 2019-09-25 正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置 WO2020063680A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP19867335.2A EP3817102B1 (en) 2018-09-26 2019-09-25 Positive electrode active material and preparation method therefor, electrochemical cell, battery module, battery pack, and apparatus
US17/131,012 US11527752B2 (en) 2018-09-26 2020-12-22 Positive active material and preparation method thereof, electrochemical battery, battery module, battery pack, and apparatus

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201811124179.6A CN110957474B (zh) 2018-09-26 2018-09-26 正极活性材料及其制备方法及电化学储能装置
CN201811124179.6 2018-09-26

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/131,012 Continuation US11527752B2 (en) 2018-09-26 2020-12-22 Positive active material and preparation method thereof, electrochemical battery, battery module, battery pack, and apparatus

Publications (1)

Publication Number Publication Date
WO2020063680A1 true WO2020063680A1 (zh) 2020-04-02

Family

ID=69949742

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2019/107909 WO2020063680A1 (zh) 2018-09-26 2019-09-25 正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置

Country Status (4)

Country Link
US (1) US11527752B2 (zh)
EP (1) EP3817102B1 (zh)
CN (1) CN110957474B (zh)
WO (1) WO2020063680A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022078701A1 (en) * 2020-10-16 2022-04-21 Basf Se Process for making a coated electrode active material
CN114927671A (zh) * 2022-06-17 2022-08-19 远景动力技术(江苏)有限公司 正极活性材料、其制备方法、电化学装置和电子设备
CN115385398A (zh) * 2022-09-22 2022-11-25 楚能新能源股份有限公司 一种掺杂改性的三元材料及其制备方法

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111916723B (zh) * 2020-07-14 2021-08-17 蜂巢能源科技有限公司 梯度掺杂的无钴正极材料及其制备方法以及锂离子电池正极和锂电池
CN113571695B (zh) * 2021-09-23 2022-01-04 长沙理工大学 一种具有包覆层的渐变式三元正极材料的制备方法
CN114843488B (zh) * 2022-06-14 2024-03-26 远景动力技术(江苏)有限公司 正极活性材料、电化学装置和电子设备
CN115036483A (zh) * 2022-06-24 2022-09-09 宁波容百新能源科技股份有限公司 一种长寿命的正极材料、其制备方法及锂离子电池
CN115490275B (zh) * 2022-09-21 2024-04-09 广东邦普循环科技有限公司 一种铁包覆硼掺杂的高镍正极材料及其制备方法和应用
CN117080416B (zh) * 2023-10-16 2024-02-20 宁波容百新能源科技股份有限公司 一种正极材料及其制备方法、锂离子电池
CN117342631B (zh) * 2023-12-05 2024-04-12 宁德时代新能源科技股份有限公司 三元前驱体及其制备方法、二次电池和用电装置
CN117393740B (zh) * 2023-12-07 2024-03-01 长虹三杰新能源有限公司 正极材料及其制备方法和钠离子电池
CN117457894B (zh) * 2023-12-25 2024-04-05 宁波容百新能源科技股份有限公司 一种多晶正极材料及其制备方法、锂离子电池

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102024950A (zh) * 2009-09-09 2011-04-20 索尼公司 正极活性物质及其制备方法、正极和非水电解质电池
CN103459321A (zh) * 2011-04-14 2013-12-18 户田工业株式会社 Li-Ni复合氧化物颗粒粉末及其制造方法、以及非水电解质二次电池
CN104409700A (zh) * 2014-11-20 2015-03-11 深圳市贝特瑞新能源材料股份有限公司 一种镍基锂离子电池正极材料及其制备方法
CN105336915A (zh) * 2014-08-13 2016-02-17 微宏动力系统（湖州）有限公司 锂离子二次电池用正极材料、其制备方法及锂离子二次电池
CN106058230A (zh) 2016-08-11 2016-10-26 合肥国轩高科动力能源有限公司 一种铝掺杂与表面修饰共改性的高镍正极材料的制备方法
CN106602021A (zh) 2016-12-22 2017-04-26 金瑞新材料科技股份有限公司 一种包覆型锂离子电池正极材料及其制备方法
KR20170063419A (ko) * 2015-11-30 2017-06-08 주식회사 엘지화학 이차전지용 양극 활물질, 이의 제조방법, 및 이를 포함하는 리튬 이차전지
CN107611384A (zh) 2017-08-30 2018-01-19 中国科学院过程工程研究所 一种高性能浓度梯度高镍材料、其制备方法及在锂离子电池的用途

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100821523B1 (ko) * 2006-08-30 2008-04-14 주식회사 엘 앤 에프 리튬 이차 전지용 양극 활물질, 이의 제조방법 및 이를포함하는 리튬 이차 전지
KR101056714B1 (ko) * 2008-11-10 2011-08-12 주식회사 엘지화학 고전압 특성이 향상된 양극 활물질
JP6172529B2 (ja) * 2014-07-22 2017-08-02 トヨタ自動車株式会社 リチウムイオン二次電池用正極活物質およびその利用
KR102312369B1 (ko) * 2014-12-16 2021-10-12 에스케이이노베이션 주식회사 리튬 이차 전지
CN105870402A (zh) * 2015-01-22 2016-08-17 辅仁大学学校财团法人辅仁大学 金属梯度掺杂锂电池正极材料
PL3248232T3 (pl) * 2015-01-23 2020-01-31 Umicore Proszki katodowe z tlenkiem litowo-niklowo- manganowo-kobaltowym do baterii litowo-jonowych o wysokim napięciu
JP6445709B2 (ja) * 2015-01-23 2018-12-26 ユミコア 高電圧リチウムイオン電池用のリチウム金属酸化物カソード粉末
US20170077496A1 (en) * 2015-09-11 2017-03-16 Fu Jen Catholic University Metal gradient-doped cathode material for lithium batteries and its production method
US10535874B2 (en) * 2015-11-30 2020-01-14 Lg Chem, Ltd. Positive electrode active material for secondary battery, method for preparing same, and secondary battery comprising same
KR102025190B1 (ko) * 2016-12-22 2019-09-25 주식회사 포스코 양극 활물질, 이의 제조 방법, 및 이를 포함하는 리튬 이차 전지

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102024950A (zh) * 2009-09-09 2011-04-20 索尼公司 正极活性物质及其制备方法、正极和非水电解质电池
CN103459321A (zh) * 2011-04-14 2013-12-18 户田工业株式会社 Li-Ni复合氧化物颗粒粉末及其制造方法、以及非水电解质二次电池
CN105336915A (zh) * 2014-08-13 2016-02-17 微宏动力系统（湖州）有限公司 锂离子二次电池用正极材料、其制备方法及锂离子二次电池
CN104409700A (zh) * 2014-11-20 2015-03-11 深圳市贝特瑞新能源材料股份有限公司 一种镍基锂离子电池正极材料及其制备方法
KR20170063419A (ko) * 2015-11-30 2017-06-08 주식회사 엘지화학 이차전지용 양극 활물질, 이의 제조방법, 및 이를 포함하는 리튬 이차전지
CN106058230A (zh) 2016-08-11 2016-10-26 合肥国轩高科动力能源有限公司 一种铝掺杂与表面修饰共改性的高镍正极材料的制备方法
CN106602021A (zh) 2016-12-22 2017-04-26 金瑞新材料科技股份有限公司 一种包覆型锂离子电池正极材料及其制备方法
CN107611384A (zh) 2017-08-30 2018-01-19 中国科学院过程工程研究所 一种高性能浓度梯度高镍材料、其制备方法及在锂离子电池的用途

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3817102A4

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2022078701A1 (en) * 2020-10-16 2022-04-21 Basf Se Process for making a coated electrode active material
CN114927671A (zh) * 2022-06-17 2022-08-19 远景动力技术(江苏)有限公司 正极活性材料、其制备方法、电化学装置和电子设备
CN115385398A (zh) * 2022-09-22 2022-11-25 楚能新能源股份有限公司 一种掺杂改性的三元材料及其制备方法
CN115385398B (zh) * 2022-09-22 2023-09-29 楚能新能源股份有限公司 一种掺杂改性的三元材料及其制备方法

Also Published As

Publication number Publication date
CN110957474B (zh) 2020-12-11
EP3817102B1 (en) 2022-07-20
US20210111405A1 (en) 2021-04-15
EP3817102A4 (en) 2021-08-11
EP3817102A1 (en) 2021-05-05
US11527752B2 (en) 2022-12-13
CN110957474A (zh) 2020-04-03

Similar Documents

Publication Publication Date Title
WO2020063680A1 (zh) 正极活性材料及其制备方法、电化学电池、电池模块、电池包及装置
WO2020164364A1 (zh) 正极活性材料及其制备方法、钠离子电池和包含钠离子电池的装置
WO2020143533A1 (zh) 正极活性材料及其制备方法、钠离子电池及包含钠离子电池的装置
JP7254875B2 (ja) リチウム二次電池用正極活物質およびこれを含むリチウム二次電池
JP2020024951A (ja) 二次電池、電池パック及び車両
WO2021057483A1 (zh) 二次电池及含有该二次电池的电池模组、电池包、装置
WO2007010915A1 (ja) 非水電解質二次電池及びその製造方法
JPWO2004105162A6 (ja) 二次電池用正極活物質、二次電池用正極、二次電池、および二次電池用正極活物質の製造方法
US20170018797A1 (en) Nonaqueous electrolyte battery and battery pack
CN113611833A (zh) 一种阳离子插层改性的CuS@CTAB电极材料在锌离子电池中的应用
CN101110477B (zh) 一种电化学储能与能量转换装置
KR101776896B1 (ko) 리튬 이차전지용 양극 활물질 및 그의 제조방법
JP7038956B2 (ja) 高出力特性を有する負極活物質及びそれを含むリチウム二次電池
US20240047732A1 (en) Lithium-ion battery, battery module, battery pack, and electrical apparatus
CN114512660A (zh) 正极活性材料前驱体及其制备方法和正极活性材料
CN107946567B (zh) 一种兼具离子与电子导体的三维多酸包覆层的锂离子电池正极材料
WO2021047324A1 (zh) 正极活性材料、其制备方法、锂离子二次电池及其相关的电池模块、电池包和装置
US11557761B2 (en) Lithium ion secondary battery
WO2021184220A1 (zh) 一种可预锂化的锂离子启停电源及其制备方法
CN113140718A (zh) 一种三维网络结构的Zn@ZnF2电极材料及其制备方法和应用
CN110544764A (zh) 正极材料
JP2000067869A (ja) 非水電解液二次電池
CN116936776B (zh) 正极活性材料、极片、电池、用电设备
WO2023236010A1 (zh) 改性高镍三元正极材料及其制备方法、应用
WO2023205993A1 (zh) 尖晶石镍锰酸锂材料及其制备方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 19867335

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2019867335

Country of ref document: EP

Effective date: 20201206

NENP Non-entry into the national phase

Ref country code: DE