WO2022012102A1 - 正极材料及其制备方法、正极复合材料及电池 - Google Patents

正极材料及其制备方法、正极复合材料及电池 Download PDF

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Publication number
WO2022012102A1
WO2022012102A1 PCT/CN2021/087569 CN2021087569W WO2022012102A1 WO 2022012102 A1 WO2022012102 A1 WO 2022012102A1 CN 2021087569 W CN2021087569 W CN 2021087569W WO 2022012102 A1 WO2022012102 A1 WO 2022012102A1
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Prior art keywords
positive electrode
electrode material
composite particles
secondary composite
particles
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PCT/CN2021/087569
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English (en)
French (fr)
Inventor
陈娜
阮泽文
田业成
邓暄炜
张南
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比亚迪股份有限公司
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Application filed by 比亚迪股份有限公司 filed Critical 比亚迪股份有限公司
Priority to EP21843281.3A priority Critical patent/EP4184615A4/en
Priority to KR1020237005002A priority patent/KR20230038262A/ko
Priority to JP2023502910A priority patent/JP2023533368A/ja
Publication of WO2022012102A1 publication Critical patent/WO2022012102A1/zh
Priority to US18/154,660 priority patent/US20230163280A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—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
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/40—Alloys based on alkali metals
    • H01M4/405—Alloys based on lithium
    • 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
    • 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
    • H01M10/058—Construction or manufacture
    • 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
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H01M4/40—Alloys based on alkali metals
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/50—Agglomerated particles
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/40—Electric properties
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/021—Physical characteristics, e.g. porosity, surface area
    • 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
    • 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
    • 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
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present application relates to the field of batteries, in particular to a positive electrode material and a preparation method thereof, a positive electrode composite material and a battery.
  • the present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a positive electrode material, which makes the battery more stable.
  • a positive electrode material comprises a plurality of secondary composite particles, each of the secondary composite particles comprises a plurality of primary particles of positive electrode material; the secondary composite particles satisfy the following relational formula 1:
  • the a represents the value of the particle size D50 of the primary particles of the positive electrode material, in ⁇ m; the b represents the value of the particle size D50 of the secondary composite particles, in ⁇ m; the c represents the The value of the specific surface area of the secondary composite particles, in m 2 /g; the d represents the number of primary particles of the positive electrode material in the secondary composite particles.
  • the particle diameter D50 of the primary particles of the positive electrode material, the particle diameter D50 of the secondary composite particles, the specific surface area of the secondary composite particles, and the positive electrode material in the secondary composite particles are determined.
  • the battery prepared by the positive electrode material has a lower battery impedance, a higher cycle capacity retention rate, and a lower thickness change rate of the battery, indicating that the battery produces less gas. , the side reaction between the positive electrode sheet and the electrolyte is less, and the battery stability is better.
  • a preparation method of a positive electrode material comprises:
  • the obtained pre-sintered mixture is subjected to first sintering, and after the first sintering is completed, first crushing is performed to obtain a positive electrode material, wherein the positive electrode material includes a plurality of secondary composite particles, and each of the secondary composite particles includes a plurality of positive electrode materials primary particle.
  • a positive electrode composite material the positive electrode composite material comprises the above-mentioned positive electrode material and a coating layer coated on the surface of the positive electrode material.
  • a battery the battery includes a positive electrode sheet, the positive electrode sheet includes a current collector and a positive electrode active layer disposed on the current collector, the positive electrode active layer includes the positive electrode composite material as described above.
  • first and second are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature defined as “first” or “second” may expressly or implicitly include one or more of that feature. Further, in the description of the present application, unless otherwise specified, "plurality" means two or more.
  • the positive electrode material includes a plurality of secondary composite particles, and each secondary composite particle includes a plurality of primary particles of the positive electrode material; the secondary composite particles satisfy the following relational formula 1:
  • the size of the particle size D50 of the primary particle of the positive electrode material is directly related to the length of the diffusion path of lithium ions in the positive electrode material.
  • the particle size D50 of the primary particle of the positive electrode material is too large, the diffusion path of the lithium ion will increase, resulting in material The capacity of the battery is low and the impedance of the battery will increase; if the particle size D50 of the primary particles of the positive electrode material is too small, the number of primary particles of the positive electrode material in the secondary composite particles of the same particle size D50 will increase, which will make the secondary The specific surface area of the secondary composite particles increases, resulting in an increase in side reactions between the secondary composite particles and the electrolyte, serious gas generation, and the cycle performance of the battery is affected.
  • the particle size D50 of the primary particles of the positive electrode material and the number of the primary particles of the positive electrode material constituting the secondary composite particles directly affect the particle size D50 and specific surface area of the secondary composite particles.
  • the particle size D50 of the primary particles of the positive electrode material is too small, the number of primary particles of the positive electrode material will increase, resulting in an increase in the specific surface area of the secondary composite particles and an increase in the area where side reactions occur. .
  • the number of primary particles of the positive electrode material in the secondary composite particles is too large. During the process of plate pressing and cycling, the primary particles of the positive electrode material will be broken, which will further lead to the appearance of new interfaces and the deterioration of battery performance.
  • the particle size D50 of the primary particles of the positive electrode material is too large, the number of primary particles of the positive electrode material corresponding to the secondary composite particles will decrease, but the primary particles of the positive electrode material with a larger particle size will directly increase the diffusion path of lithium ions, resulting in the deterioration of the material.
  • the capacity is low, the battery impedance increases, and the power performance decreases.
  • the particle size D50 of the primary particles of the positive electrode material in the secondary composite particles is found in the secondary composite particles.
  • the battery prepared by the positive electrode material has a lower battery impedance, a higher cycle capacity retention rate, and a lower thickness change rate of the battery, indicating that the battery produces less gas, and the positive electrode sheet and the The electrolyte has fewer side reactions and better battery stability.
  • the secondary composite particles satisfy: 2.5 ⁇ 0.1d/a+b*c ⁇ 9. It can be seen from the experimental data that the secondary composite particles have better performance effects in the above-mentioned value range.
  • the value range of a may be: 0.5 ⁇ a ⁇ 3.5. Furthermore, the value range of a is preferably: 1.5 ⁇ a ⁇ 2.5.
  • the value range of b may be: 3 ⁇ b ⁇ 12. Furthermore, the value range of b is preferably: 4.5 ⁇ b ⁇ 7.
  • the value range of c may be: 0.3 ⁇ c ⁇ 1.2. Furthermore, the value range of c is preferably: 0.5 ⁇ c ⁇ 1.0.
  • the value range of d may be: 1 ⁇ d ⁇ 50. Furthermore, the value range of d is preferably: 3 ⁇ d ⁇ 20.
  • the primary particles of the positive electrode material are layered structure positive electrode materials.
  • Embodiments of the present application further provide a method for preparing a positive electrode material, and the method for preparing a positive electrode material may include step S100 and step S200.
  • the detailed steps are as follows.
  • step S100 the first precursor and the second precursor are mixed and pre-sintered.
  • the first precursor includes at least one of Ni e Co f Q g (OH) 2 , Ni e Co f Q g O, or hydroxides or oxides of Ni, Co, and Q, and in Ni e Co f Q
  • the second precursor includes at least one of lithium hydroxide, lithium carbonate, lithium nitrate, and lithium acetate. The molar ratio of the first precursor and the second precursor is 1:(1-1.05).
  • the pre-sintering temperature may be 200°C-500°C, and the pre-sintering time is 4h-6h.
  • the pre-sintering can be carried out in the roller kiln without stirring.
  • the purpose of pre-sintering is to volatilize the water in the first precursor and the second precursor, which is more conducive to the full reaction of the first precursor and the second precursor in the first sintering process, and is conducive to the formation of the positive electrode material.
  • step S200 the obtained pre-sintered mixture is subjected to first sintering, and after the first sintering is completed, first crushing is performed to obtain a positive electrode material, the positive electrode material includes a plurality of secondary composite particles, and each secondary composite particle includes a plurality of positive electrode materials once particles.
  • the particle diameter D50 of the primary particles of the positive electrode material, the particle diameter D50 of the secondary composite particles, the specific surface area of the secondary composite particles, and the size of the primary particles of the positive electrode material in the secondary composite particles can be determined. number.
  • the primary particles of the positive electrode material refer to the particles with different orientations in the interior of the positive electrode material tested by using EBSD (Backscattered Electron Diffraction Technology) as the primary particles of the positive electrode material.
  • Orientation refers to the orientation of the particles on the coordinate axis at any point on the interface shown. That is to say, by testing the positive electrode material by EBSD, a plurality of particles with different orientations can be observed, wherein each particle with different orientations is the primary particle of the positive electrode material.
  • Secondary composite particles refer to material particles having a plurality of primary particles of positive electrode material bound together. That is, there are a plurality of primary particles of positive electrode material with different orientations in the secondary composite particles.
  • the first sintering sequentially includes a first heating section, a first constant temperature section, a second heating section, a second constant temperature section, and a cooling section.
  • the temperature of the first heating section is 200°C-800°C, and the time of the first heating section is 1.5h-3.5h; the temperature of the first constant temperature section is 700°C-800°C, and the time of the first constant temperature section is 5.0h-8.0 h; the temperature of the second heating section is 800°C-1100°C, and the time of the second heating section is 2.0h-3.5h; the temperature of the second constant temperature section is 1000°C-1100°C, and the time of the second constant temperature section is 8.0h -10.0h.
  • the first heating section and the second heating section may be continuous heating, or may continue heating after stopping heating for a short period of time in each heating section. It is preferable to use continuous temperature rise.
  • the first precursor and the second precursor undergo a thermal decomposition reaction in the first heating stage and the second heating stage, and the decomposed by-products include water and/or carbon dioxide.
  • the first precursor includes hydroxide
  • the first precursor will Water and metal oxide are decomposed
  • the second precursor will decompose water and lithium oxide, wherein, when the second precursor includes lithium carbonate, lithium carbonate will decompose carbon dioxide and lithium oxide.
  • the first heating stage and the second heating stage are performed in a heating furnace with an exhaust duct.
  • the exhaust pipe can remove gases such as water vapor and carbon dioxide generated by the thermal decomposition of the first precursor and/or the lithium source, so as to accelerate the decomposition reaction of the first precursor and the second precursor.
  • the solid-phase reaction refers to the reaction in which lithium oxide and metal oxide react to form primary particles of positive electrode material.
  • the solid-phase reaction occurs in the first constant temperature section and the second constant temperature section, and ion diffusion occurs between lithium oxide and metal oxide.
  • the reaction temperature and reaction time in the constant temperature section will affect the particle size and crystallinity of the primary particles of the positive electrode material. It will directly affect the final performance of the cathode material. Exhaust pipes may not be required in the first constant temperature section and the second constant temperature section. It should be noted that the temperature in the constant temperature section may fluctuate within a certain preset range, for example, the temperature of the first constant temperature section may fluctuate within 750°C-780°C.
  • the heating section and the constant temperature section are alternately used for sintering, which can make the first precursor and the second precursor react more fully.
  • the cooling section includes a first cooling subsection and a second cooling subsection, the temperature of the first cooling subsection is 1100°C-600°C, the time of the first cooling subsection is 2.5-4.0h; the temperature of the second cooling subsection is 600°C-200°C, the time of the second cooling subsection is 0.5-2.0h.
  • the first cooling subsection and the second cooling subsection may be continuously cooling, or may continue cooling after stopping cooling for a short period of time in each cooling subsection. It is preferable to use continuous cooling.
  • the present application finds through experiments that when the temperature and time of the first heating section, the first constant temperature section, the second heating section, the second constant temperature section and the cooling section in the first sintering are within the above ranges, it has better performance, and in the first sintering After the first sintering is completed, the particle size of the primary particles of the positive electrode material can be determined, and after the first sintering, the primary particles of the positive electrode material will agglomerate to form agglomerates.
  • the first crushing includes: performing ball milling on the sintered agglomerate after the first sintering to obtain preliminary crushed objects, and then performing air crushing on the preliminary crushed objects; wherein, the rotational speed of the ball milling is 4000r/min-8000r/min, and the time of the ball milling is It is 1.5h-2.5h, the pressure of gas crushing is 5MPa-10MPa, and the time of gas crushing is 0.5h-1.5h.
  • the particle size D50 of the secondary composite particles, the specific surface area of the secondary composite particles, and the number of primary particles of the positive electrode material in the secondary composite particles can be determined.
  • the positive electrode composite material includes the positive electrode material as described above and a coating layer coated on the surface of the positive electrode material.
  • the coating layer can be a protective layer formed on the surface of the positive electrode material, which reduces the side reaction between the positive electrode material and the electrolyte, contributes to the stability of the surface structure of the material, and improves the cycle performance of the material; or the coating layer is formed on the positive electrode material.
  • the thermal barrier layer formed on the surface reduces the thermal diffusion rate of the material and improves the safety of the material.
  • the mass ratio of the coating layer in the cathode composite material is 300 ppm-900 ppm.
  • the coating layer can effectively reduce the side reaction between the secondary composite particles and the electrolyte, and to a certain extent, the gas production of the material can be reduced, and the coating layer can also play the role of thermal barrier. , slow down thermal diffusion and improve the safety performance of the material.
  • the amount of the coating layer is too large, there will be a layer of substances different from the bulk structure on the surface of the secondary composite particles, which is not conducive to the extraction of lithium ions, reduces the content of active components in the secondary composite particles, and is not conducive to improving the positive electrode.
  • the specific capacity, rate, and low-temperature performance of the material if the amount of the coating layer is too small, the thickness of the coating layer will be too thin or the surface area of the secondary composite particles that can be coated will be insufficient, and there will be exposed secondary composite particles in contact with the electrolyte.
  • the phenomenon of side reactions is not conducive to the performance of the material. It is found through experiments in the present application that when the mass ratio of the coating layer to the positive electrode composite material is within the above range and the above relational formula 1 is satisfied, the positive electrode composite material and the prepared battery have better performance effects.
  • the material of the cladding layer is a hydroxide and/or oxide of at least one element of Zr, Mn, Y, Ti, W, Al, Co, B and Mg. More preferably, the material of the coating layer is at least one of Ti 3 O 4 , Mg(OH) 2 , W 2 O 3 , Al 2 O 3 , Co(OH) 2 and B(OH) 3 .
  • the coating layer can be formed on the surface of the positive electrode material by the following method to obtain the positive electrode composite material.
  • the positive electrode material and the coating material are mixed, and then the second sintering is performed, and then the mixture after the second sintering is subjected to the second crushing to obtain the positive electrode composite material.
  • the temperature of the second sintering is 500° C.-800° C.
  • the time of the second sintering is 5.0h-8.0h; /min, the second crushing time is 0.5-1h.
  • the purpose of the second sintering is to sinter the coating material on the surface of the secondary composite particles to form a coating layer to obtain a positive electrode composite material.
  • the second crushing is to separate the secondary composite particles bonded together in the second sintering process, and its purpose is to separate the coating material between the secondary composite particles.
  • the second crushing adopts the parameters in the above range without affecting the secondary The particle size of the composite particles.
  • the present application also provides a battery, the battery includes a positive electrode sheet, the positive electrode sheet includes a current collector and a positive electrode active layer disposed on the current collector, and the positive electrode active layer includes the positive electrode composite material according to any one of the above.
  • the positive electrode active layer is a coating formed by coating the positive electrode slurry on the current collector.
  • the positive electrode sheet includes the above-mentioned positive electrode composite material, so that the polar sheet compaction density of the positive electrode sheet is above 3.5 g/mm 3 , and the ratio of the oriented 003 peak intensity to the 110 peak intensity after the polar piece is pressed is lower, indicating that the weaker the orientation is , it is not easy to expand during charging and discharging.
  • the battery includes the positive electrode sheet as above, which can reduce the battery impedance and the thickness change rate of the battery in high temperature storage, and can improve the capacity retention rate of the battery cycle for 500 times, and improve the electrical performance of the battery.
  • the positive electrode slurry further includes a conductive agent and a binder, and the mass ratio of the positive electrode composite material, the conductive agent, and the binder is 100:(0.5-2):(0.5-2).
  • the positive electrode active layer includes a positive electrode composite material, a conductive agent and a binder, and the mass ratio of the positive electrode composite material, the conductive agent and the binder is 100:(0.5-2):(0.5-2).
  • the conductive agent includes at least one of carbon tubes, carbon black, and graphene.
  • the conductive agent includes three types of carbon tubes, carbon black, and graphene.
  • the binder includes a first copolymer obtained by copolymerizing vinylidene fluoride and an ethylene compound containing active groups, and a second copolymer obtained by copolymerizing vinylidene fluoride and chlorotrifluoroethylene.
  • the mass ratio of vinylidene fluoride and ethylene compound containing active group is (85.00-99.99):(0.01-15.00)
  • the active group includes carboxyl group, epoxy group, hydroxyl group and sulfonic acid At least one of the bases
  • the mass ratio of vinylidene fluoride and chlorotrifluoroethylene is (85.00-99.05):(0.05-15.00).
  • Step S100 the nickel-cobalt-manganese precursor and second precursor mixed and pre-sintered at a roller kiln, in the present embodiment, nickel cobalt manganese precursor selected Ni 0.7 Co 0.1 Mn 0.2 (OH ) 2, a second precursor Lithium hydroxide is used as the body, the pre-sintering temperature is 200°C-500°C, and the pre-sintering time is 4h-6h.
  • step S200 the obtained pre-sintered mixture is subjected to first sintering, and after the first sintering is completed, first crushing is performed to obtain a positive electrode material, and the first sintering sequentially includes a first heating section, a first constant temperature section, a second heating section, and a second heating section.
  • Constant temperature section and cooling section the temperature of the first heating section is 200°C-800°C, and the time of the first heating section is 1.5h-3.5h; the temperature of the first constant temperature section is 700°C-800°C, and the temperature of the first constant temperature section The time is 5.0h-8.0h; the temperature of the second heating section is 800°C-1100°C, the time of the second heating section is 2.0h-3.5h; the temperature of the second constant temperature section is 1000°C-1100°C, the second constant temperature The time of the subsection is 8.0h-10.0h; the cooling section includes the first cooling subsection and the second cooling subsection, the temperature of the first cooling subsection is 1100°C-600°C, and the time of the first cooling subsection is 2.5- 4.0h; the temperature of the second cooling subsection is 600°C-200°C, and the time of the second cooling subsection is 0.5-2.0h; the first crushing includes ball milling the sintered agglomerate after the first sintering to obtain preliminary crushing The initial crushed material is then subjected to air crushing;
  • the obtained positive electrode material includes a plurality of secondary composite particles, each secondary composite particle includes a plurality of primary particles of positive electrode material, and the primary particles of positive electrode material are layered structure positive electrode materials, and the chemical formula is LiNi 0.7 Co 0.1 Mn 0.2 .
  • the preparation parameters were adjusted to obtain different positive electrode materials, and the particle size D50 of the positive electrode material, the specific surface area of the secondary composite particles, the number of primary particles of the positive electrode material in the secondary composite particles and the particle size D50 of the positive electrode material were measured.
  • the results are summarized in Table 1, where a represents the value of the particle size D50 of the primary particles of the positive electrode material, in ⁇ m; b represents the value of the particle size D50 of the secondary composite particles, in ⁇ m; c represents the value of the particle size of the secondary composite particles.
  • the value of the specific surface area, in m 2 /g; d represents the number of primary particles of the positive electrode material in the secondary composite particles.
  • the D50 test method for the particle size of the primary particle of the positive electrode material is: using the CP-SEM image at 5000 times, count the long side size of about 300 primary particles of the positive electrode material, and make a statistical distribution of the data to obtain the size of the primary particle of the positive electrode material. Diameter D50.
  • the test method for the particle size D50 of the secondary composite particles is as follows: the test equipment is a laser particle size analyzer, and the reference model is Malvern 2000/3000. The test method is: disperse in deionized water, ultrasonic for 10min; test to obtain the particle size D50 of the secondary composite particles.
  • test method for the specific surface area of the secondary composite particles is: using the gas adsorption method, multi-point test, and the test standard is ISO-9277/GB/T19587-2004.
  • the test method for the number of primary particles of the positive electrode material in the secondary composite particles is: using EBSD (backscattered electron diffraction technology) to test the various orientations of the primary particles of the positive electrode material in the secondary composite particles. Different orientations show different colors under EBSD.
  • EBSD backscattered electron diffraction technology
  • Preparation of positive electrode composite material mixing the prepared positive electrode material and the coating material, then performing second sintering, and then performing second crushing on the mixture after the second sintering to obtain a positive electrode composite material.
  • the coating material is selected from Ti 3 O 4 , and the content of the coating material in the formed positive electrode composite material is 300-900 ppm.
  • the temperature of the second sintering is 500°C-800°C, and the time of the second sintering is 5.0h-8.0h; 0.5-1h.
  • the prepared positive electrode composite material is mixed with a conductive agent and a binder according to a mass ratio of 100:1.2:1.2 to prepare a positive electrode slurry, wherein the conductive agent is composed of carbon tubes, carbon black and graphene three.
  • the mass ratio of carbon tube, carbon black and graphene is 0.6: 0.5: 0.3
  • the binder is the first copolymer obtained by copolymerizing vinylidene fluoride and the ethylene compound containing active groups and the first copolymer obtained by copolymerizing vinylidene fluoride and vinylidene fluoride.
  • the second copolymer obtained by the copolymerization of chlorotrifluoroethylene is composed, and the molar ratio of the first copolymer and the second copolymer is 1:1.
  • vinylidene fluoride and the ethylene compound containing active groups are The mass ratio is 95.00:5.00, and the active groups include carboxyl groups; in the second copolymer, the mass ratio of vinylidene fluoride and chlorotrifluoroethylene is 96.00:4.00.
  • the prepared positive electrode slurry was subjected to performance tests, including the pole piece compaction density test, the pole piece orientation test after pressing, the battery impedance test, the cycle performance test and the storage performance test.
  • the test method of the compaction density of the pole piece is as follows: apply the positive electrode slurry prepared in each example on the pole piece to form an unpressed positive pole piece, make the unpressed positive pole piece into a size of 40*100mm, and use the Ono tablet Press the machine to press, and calculate the compaction density of the pole piece according to the surface density of the pole piece and the thickness of the pole piece after pressing.
  • test method for the orientation of the pole piece after pressing is: according to the general rule of JY/T 009-1996 polycrystalline X-ray diffraction method; the peak intensity ratio of (003) and (110) are used to characterize.
  • the battery impedance test method is as follows: each prepared positive electrode material is made into a corresponding battery, the battery is adjusted to 60% SOC, the current is 3C, and the charging and discharging time is 10s, and the DCIR of the battery is tested; The product of the battery's 1/3C discharge capacity is used as a characterization of the battery's impedance.
  • the cycle performance test method is as follows: each prepared positive electrode material is made into a corresponding battery, and the test method is: temperature condition: 45 ⁇ 5°C; charging: 1C constant current charge to 4.2V; discharge: 1C constant current discharge to 2.5V; After 500 cycles, the discharge capacity C1 of the first cycle was used as a reference to calculate the capacity retention rate, which was recorded as cycle 45°C-C500 in Table 2.
  • each prepared positive electrode material is made into a corresponding battery, the battery is charged to 4.2V according to 0.2C constant current, placed at room temperature for 2 hours, and the initial thickness of the battery is recorded; the battery is placed in a constant temperature cabinet at 60 °C for 28D , record the thickness after storage, and calculate the thickness change, which is recorded as the 60-28D thickness change rate in Table 2.
  • Comparative Examples 1-3 prepared secondary composite particles according to a method different from the above-mentioned embodiment, and the values of a, b, c and d in the secondary composite particles are shown in Table 1.
  • Comparative Example 4 the preparation method of Comparative Example 4 is roughly the same as the preparation method of Example 1, the difference is that in the first sintering, the method of cross sintering between the heating section and the constant temperature section is not adopted, but the temperature is directly heated to 1000°C- Sintering at 1100°C, and the sintering time is the same as the sintering time in Example 1.
  • Comparative Example 5 the preparation method of Comparative Example 5 is roughly the same as the preparation method of Example 1, the difference is that in the first sintering, the cross sintering method of the heating section and the constant temperature section is not adopted, but three sintering sections are included, The temperature of the first sintering section is 400-600°C for 4 hours, the temperature of the second sintering section is 600-700°C for 4 hours, and the temperature of the third sintering section is 700-900°C for 13 hours.
  • Comparative Example 6 the preparation method of Comparative Example 6 is roughly the same as the preparation method of Example 1, the difference is that a heating section and a constant temperature section are used for sintering, wherein the temperature of the heating section is 200°C-1100°C, and the temperature rises
  • the time of the constant temperature section is the same as the sum of the time of the first heating section and the second heating section in Example 1
  • the temperature of the constant temperature section is 1000 °C-1100 °C
  • the time of the constant temperature section is the same as that of the first constant temperature section and the second heating section in Example 1.
  • the total time of the constant temperature segment is the same.
  • Comparative Example 7 the preparation method of Comparative Example 7 is roughly the same as the preparation method of Example 1, the difference is that the cooling time of the cooling section is 1h, that is, the cooling time of Comparative Example 7 is much shorter than that of Example 1.
  • Comparative Example 8 the preparation method of Comparative Example 8 is roughly the same as that of Example 1, except that the rotational speed of the ball mill in the first crushing process is 2000 r/min, which is lower than that of Example 1.
  • Comparative Example 9 the preparation method of Comparative Example 9 is roughly the same as that of Example 1, except that the rotational speed of the ball mill in the first crushing process is 10000 r/min, which is greater than that of Example 1.
  • Comparative Example 10 the preparation method of Comparative Example 10 is roughly the same as the preparation method of Example 1, the difference is that the pressure of gas crushing is 3 MPa, which is lower than that of Example 1.
  • Comparative Example 11 the preparation method of Comparative Example 10 is roughly the same as the preparation method of Example 1, the difference is that the pressure of gas crushing is 20MPa, which is greater than that of Example 1.
  • Comparative Example 12 the preparation method of Comparative Example 12 is substantially the same as the preparation method of Example 1, the difference is that the amount of the coating material added in step S300 is 2000 ppm.
  • Comparative Example 13 small particle material was prepared, the small particle material was composed of 1-3 primary particles of positive electrode material, and the primary particle of positive electrode material was LiNi 0.7 Co 0.1 Mn 0.2 .
  • the secondary particulate material is prepared, the secondary particulate material is composed of multiple primary particles of positive electrode material, and the particle size D50 of the secondary particulate material is 50 ⁇ m, that is, the secondary particulate material has a very large number of primary particles of positive electrode material.
  • the primary particle of the positive electrode material is LiNi 0.7 Co 0.1 Mn 0.2.
  • the positive electrode material prepared in Example 1 Example 9 embodiment has superior performance results in a pole piece compacted density, can reach up to 3.70g / cm 3, pole pieces compacted density
  • Comparative Example 1 It can be seen from Comparative Example 1 that the value of relational formula 1 is not within the scope of the present application, and when the number of primary particles of positive electrode material in the secondary composite particles is too large, the Fragmentation will occur between them, which further leads to the appearance of new interfaces, and the battery performance deteriorates. The orientation, cycle performance and storage performance of the pole pieces of Comparative Example 1 are all poor.
  • Comparative Example 2 It can be seen from Comparative Example 2 that the value of Relational Formula 1 is not within the scope of the present application, and when the particle size D50 of the primary particles of the positive electrode material is too large, it will directly affect the length of the diffusion path of lithium ions, resulting in a low capacity of the material. , the battery impedance increases, the cycle performance and storage performance decrease, and the cycle performance and storage performance of Comparative Example 2 are both poor.
  • Comparative Example 3 It can be seen from Comparative Example 3 that the value of the relational formula 1 is not within the scope of the present application, and the specific surface area of the secondary composite particles is too large and the number of primary particles of the positive electrode material in the secondary composite particles is too large. If the specific surface area of the particles is too large, the side reactions between the secondary composite particles and the electrolyte will increase, the gas production will be serious, and the cycle performance of the battery will be affected. During the cycle, the primary particles of the positive electrode material will be broken, which will further lead to the appearance of new interfaces and the deterioration of the battery performance. The compaction density of the pole piece, the orientation of the pole piece after pressing, the battery impedance, the cycle performance and the storage performance of Comparative Example 3 Performance is poor.
  • Comparative Example 4 shows that the performance data of the prepared secondary composite particles are slightly worse than those of Example 1-Example 9 without adopting the method of temperature segmented sintering and cross-sintering of heating segment and constant temperature segment. However, it is better than the data of Comparative Example 1-Comparative Example 3, which shows that the use of the first sintering method of the present application is beneficial to form a positive electrode material that satisfies the relational formula 1 of the present application.
  • Comparative Example 5 It can be seen from Comparative Example 5 that although the temperature segmented sintering method is adopted, the cross-sintering method of the heating section and the constant temperature section is not adopted. The data is slightly worse, but better than the data of Comparative Example 1-Comparative Example 3, which shows that the use of the first sintering method of the present application is beneficial to form a positive electrode material that satisfies the relational formula 1 of the present application.
  • Comparative Example 6 and Comparative Example 7 that the first sintering within the scope of the present application is conducive to the formation of a positive electrode material that satisfies Relation 1 of the present application.
  • Comparative Example 6 only one temperature rise and one constant temperature are used to make the lithium source and the precursor materials during thermal decomposition pre insufficient, resulting in a moisture excluded insufficient or CO 2, a positive electrode material during sintering can not be sufficiently crystallized.
  • Comparative Example 7 if the cooling rate is too fast, a large amount of stress will remain inside the secondary composite particles, resulting in a large amount of stress inside the material particles after the material is rapidly cooled, and the primary particles and secondary composite particles of the positive electrode material will have different degrees of stress. At the same time, cracks occur in the subsequent use process and cycle process, which affects the performance of the material.
  • Comparative Example 10 and Comparative Example 11 the gas crushing pressure within the scope of the present application is conducive to the formation of a positive electrode material that satisfies the relationship 1 of the present application. If the gas crushing pressure is too small, the recombination of the secondary particles will be too large, and the secondary particles will become too large. The particle size distribution of the composite particles becomes wider, and if the gas crushing pressure is too high, the secondary composite particles are too small, and the particle size distribution of the secondary composite particles becomes wider, and the fine powder increases, which affects the performance of the material.
  • Comparative Example 12 It can be seen from Comparative Example 12 that more coating materials on the surface of the positive electrode material will lead to difficulty in deintercalating lithium during the charging and discharging process of the material.
  • the impedance of the battery in Comparative Example 12 increases, but the cycle performance and storage performance are still comparable. A ratio of 1-5 works better.

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Abstract

提供一种正极材料包括多个二次复合颗粒，每个二次复合颗粒包括多个正极材料一次颗粒；二次复合颗粒满足：0.9≤0.1d/a+b*c≤20，其中，a表示正极材料一次颗粒的粒径D50的值，单位为μm；b表示二次复合颗粒的粒径D50的值，单位为μm；c表示二次复合颗粒的比表面积的值，单位为m 2/g；d表示二次复合颗粒中正极材料一次颗粒的个数。

Description

正极材料及其制备方法、正极复合材料及电池
相关申请的交叉引用
本申请要求比亚迪股份有限公司于2020年07月15日提交的、申请名称为“正极材料及其制备方法、正极复合材料及电池”的、中国专利申请号“202010681792.9”的优先权。
技术领域
本申请涉及电池领域，具体涉及一种正极材料及其制备方法、正极复合材料及电池。
背景技术
目前市场上比较普遍的两种正极材料设计，其中一种是由一个或者个数很少(不超过5个)的一次颗粒构成，该材料具有结构稳定性好、循环性能好、储存产气少等优点的同时还存在一些缺点，例如同样金属比例下，其容量发挥低，电池阻抗高以及功率差等缺点；另一种是由很多个一次颗粒构成的二次颗粒材料，该材料同样存在很多问题，例如在相同粒径的二次颗粒材料中，一次颗粒数量多会使得一次颗粒太小，比表面积大，与电解液副反应，产气严重；该二次颗粒材料在压片过程中易破碎，循环性能差，热稳定性差，安全性差等。
发明内容
本申请旨在至少解决现有技术中存在的技术问题之一。为此，本申请提出一种正极材料，所述正极材料使电池的稳定性更好。
一种正极材料，所述正极材料包括多个二次复合颗粒，每个所述二次复合颗粒包括多个正极材料一次颗粒；所述二次复合颗粒满足以下关系式一：
0.9≤0.1d/a+b*c≤20(关系式一)
其中，所述a表示所述正极材料一次颗粒的粒径D50的值，单位为μm；所述b表示所述二次复合颗粒的粒径D50的值，单位为μm；所述c表示所述二次复合颗粒的比表面积的值，单位为m 2/g；所述d表示所述二次复合颗粒中所述正极材料一次颗粒的个数。
由此，本申请提供的正极材料中的二次复合颗粒中将正极材料一次颗粒的粒径D50、二次复合颗粒的粒径D50、二次复合颗粒的比表面积以及二次复合颗粒中正极材料一次颗粒的个数设置满足上述关系式一时，正极材料所制备的电池具有较低的电池阻抗，电池具有较高的循环容量保持率，且电池的厚度变化率较低，说明电池产气较少，正极片与电解液的副反应较少，电池稳定性更好。
一种正极材料的制备方法，所述正极材料的制备方法包括：
将第一前驱体和第二前驱体混合并进行预烧结；
将所得预烧结混合物进行第一烧结，在第一烧结完成后进行第一破碎，得到正极材料，所述正极材料包括多个二次复合颗粒，每个所述二次复合颗粒包括多个正极材料一次颗粒。
一种正极复合材料，所述正极复合材料包括如上面所述的正极材料和包覆于所述正极材料表面的包覆层。
一种电池，所述电池包括正极片，所述正极片包括集流体以及设置于所述集流体上的正极活性层，所述正极活性层包括如上面所述的正极复合材料。
本申请的附加方面和优点将在下面的描述中部分给出，部分将从下面的描述中变得明显，或通过本申请的实践了解到。
具体实施方式
下面详细描述本申请的实施例，所述实施例的示例在附图中示出，其中自始至终相同或类似的标号表示相同或类似的元件或具有相同或类似功能的元件。下面通过参考附图描述的实施例是示例性的，仅用于解释本申请，而不能理解为对本申请的限制。
需要说明的是，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。进一步地，在本申请的描述中，除非另有说明，“多个”的含义是两个或两个以上。
根据本申请实施例的正极材料，正极材料包括多个二次复合颗粒，每个二次复合颗粒包括多个正极材料一次颗粒；二次复合颗粒满足以下关系式一：
0.9≤0.1d/a+b*c≤20(关系式一)
其中，a表示正极材料一次颗粒的粒径D50的值，单位为μm；b表示二次复合颗粒的粒径D50的值，单位为μm；c表示二次复合颗粒的比表面积的值，单位为m 2/g；d表示二次复合颗粒中正极材料一次颗粒的个数。
在电池的充放电过程中，锂离子会在正极材料和负极材料中脱/嵌，锂离子的脱/嵌速度影响电池的电性能。在本申请中，正极材料一次颗粒的粒径D50的大小与锂离子在正极材料中扩散路径的长短直接相关，正极材料一次颗粒的粒径D50过大，会增加锂离子的扩散路径，导致材料的容量发挥偏低同时电池的阻抗会增加；如果正极材料一次颗粒的粒径D50过小，在相同粒径D50的二次复合颗粒中正极材料一次颗粒的个数就会增加，进而会使得二次复合颗粒的比表面积增加，造成二次复合颗粒和电解液副反应增加，产气严重，电池的循环性能受到影响。
正极材料一次颗粒的粒径D50以及组成二次复合颗粒的正极材料一次颗粒的个数直接影响了二次复合颗粒的粒径D50以及比表面积。在相同的二次复合颗粒的粒径设计下，正极材料一次颗粒的粒径D50过小，正极材料一次颗粒的个数会增加，造成二次复合颗粒的比表面积增加，发生副反应的面积增加。同时二次复合颗粒中正极材料一次颗粒个数过多，在极片压片以及循环过程中，正极材料一次颗粒之间会发生破碎，进而更一步导致新的界 面出现，电池性能劣化。正极材料一次颗粒的粒径D50过大，相应组成二次复合颗粒的正极材料一次颗粒的个数减小，但粒径较大的正极材料一次颗粒会直接增加锂离子的扩散路径，导致材料的容量发挥偏低，电池阻抗增加，功率性能降低。
本申请通过大量实验数据发现在二次复合颗粒中的正极材料一次颗粒的粒径D50、二次复合颗粒的粒径D50、二次复合颗粒的比表面积以及二次复合颗粒中正极材料一次颗粒的个数满足上述关系式一时，正极材料所制备的电池具有较低的电池阻抗，电池具有较高的循环容量保持率，且电池的厚度变化率较低，说明电池产气较少，正极片与电解液的副反应较少，电池稳定性更好。
在一些实施例中，二次复合颗粒满足：2.5≤0.1d/a+b*c≤9。通过实验数据可知，在上述取值范围二次复合颗粒具有较佳的性能效果。
其中，a的取值范围可以为：0.5≤a≤3.5。进而a的取值范围优选为：1.5≤a≤2.5。
在一些实施例中，b的取值范围可以为：3≤b≤12。进而b的取值范围优选为：4.5≤b≤7。
其中，c的取值范围可以为：0.3≤c≤1.2。进而c的取值范围优选为：0.5≤c≤1.0。
在一些实施例中，d的取值范围可以为：1≤d≤50。进而d的取值范围为优选：3≤d≤20。
在一些实施例中，正极材料一次颗粒为层状结构正极材料。
正极材料一次颗粒为LiNi xCo yM z，x的取值范围为：0.33≤x≤0.98，y的取值范围为：0.01≤y≤0.33，z的取值范围为：0.01≤z≤0.33，且x+y+z＝1，M为Mn、Al、Zr、Ti、Y、Sr和W中的至少一种。
本申请实施例还提供一种正极材料的制备方法，正极材料的制备方法可以包括步骤S100和步骤S200。详细步骤如下。
步骤S100，将第一前驱体和第二前驱体混合并进行预烧结。
其中，第一前驱体包括Ni eCo fQ g(OH) 2、Ni eCo fQ gO或者Ni、Co、Q的氢氧化物或氧化物中的至少一种，在Ni eCo fQ g(OH) 2和Ni eCo fQ gO中的e、f、g的取值范围为：0.33≤e≤0.98，0.01≤f≤0.33，0.01≤g≤0.33，且e+f+g＝1，Q为Mn、Al、Zr、Ti、Y、Sr和W中的至少一种。第二前驱体包括氢氧化锂、碳酸锂、硝酸锂和醋酸锂中的至少一种。第一前驱体和第二前驱体的摩尔比为1∶(1-1.05)。
在一些实施例中，预烧结的温度可以为200℃-500℃，预烧结的时间为4h-6h。预烧结的过程中可以不需要搅拌，在辊道窑中进行预烧结。预烧结的目的是将第一前驱体和第二前驱体中的水分挥发出来，更有利于第一前驱体与第二前驱体在第一烧结过程中充分反应，有利于正极材料的形成。
步骤S200，将所得预烧结混合物进行第一烧结，在第一烧结完成后进行第一破碎，得到正极材料，正极材料包括多个二次复合颗粒，每个二次复合颗粒包括多个正极材料一次颗粒。在第一烧结和第一破碎完成后可确定正极材料一次颗粒的粒径D50、二次复合颗粒的粒径D50、二次复合颗粒的比表面积以及二次复合颗粒中的正极材料一次颗粒的个数。
其中，正极材料一次颗粒是指利用EBSD(背散射电子衍射技术)测试正极材料内部中取向不同的颗粒为正极材料一次颗粒。取向是指颗粒在所示界面上以任一点为原点的坐标 轴上的取向。也就是说，通过EBSD测试正极材料，可观察到多个取向不同的颗粒，其中每个取向不同的颗粒即为正极材料一次颗粒。
二次复合颗粒是指具有多个正极材料一次颗粒粘结在一起的材料颗粒。即在二次复合颗粒中具有多个取向不同的正极材料一次颗粒。
在一些实施例中，第一烧结依次包括第一升温段、第一恒温段、第二升温段、第二恒温段以及降温段。
第一升温段的温度为200℃-800℃，第一升温段的时间为1.5h-3.5h；第一恒温段的温度为700℃-800℃，第一恒温段的时间为5.0h-8.0h；第二升温段的温度为800℃-1100℃，第二升温段的时间为2.0h-3.5h；第二恒温段的温度为1000℃-1100℃，第二恒温段的时间为8.0h-10.0h。
其中，第一升温段和第二升温段可以是持续升温，也可以是在每个升温段中停止升温一小段时间后继续升温。优选的采用持续升温。
第一前驱体和第二前驱体在第一升温段以及第二升温段发生热分解反应，分解的副产物包括水和/或二氧化碳，其中第一前驱体包括氢氧化物时，第一前驱体会分解出水和金属氧化物，第二前驱体会分解出水和氧化锂，其中，在第二前驱体包括碳酸锂时，碳酸锂会分解出二氧化碳和氧化锂。可选地，第一升温段和第二升温段在具有排风管的加热炉进行。排风管可排除第一前驱体和/或锂源热分解产生的水蒸气和二氧化碳等气体，以加快第一前驱体和第二前驱体的分解反应。在第一升温段和第二升温段的升温过快，会使得分解反应不充分，副产物排不干净，会对后面的固相反应产生副作用，一方面会腐蚀后续反应的设备，另一方面会造成正极材料表面的游离锂含量过高，正极材料阻抗会偏大。固相反应是指氧化锂和金属氧化物反应生成正极材料一次颗粒的反应。
第一恒温段和第二恒温段发生固相反应，锂氧化物和金属氧化物发生离子扩散，恒温段的反应温度和反应时间会影响正极材料一次颗粒的粒径大小和结晶程度的好坏，会直接影响正极材料的最终性能。在第一恒温段和第二恒温段中可不需要排风管。需要说明的是，在恒温段的温度可在一定预设范围内波动，例如第一恒温段的温度可在750℃-780℃内波动。
在第一烧结中采用升温段和恒温段交替的方式进行烧结，可以使第一前驱体和第二前驱体反应的更充分。
降温段包括第一降温子段和第二降温子段，第一降温子段的温度为1100℃-600℃，第一降温子段的时间为2.5-4.0h；第二降温子段的温度为600℃-200℃，第二降温子段的时间为0.5-2.0h。其中第一降温子段和第二降温子段可以是持续降温，也可以是在每个降温子段中停止降温一小段时间后继续降温。优选的采用持续降温。
在降温段，如果材料以较高温度出炉，会对后面的设备产生腐蚀；如果降温过快，二次复合颗粒内部会残存大量的应力，导致材料在后续的使用过程中、循环过程中发生裂纹，影响材料的性能。
本申请通过实验发现当第一烧结中第一升温段、第一恒温段、第二升温段、第二恒温段 以及降温段的温度和时间在上述范围内时，具有较好的性能，且在第一烧结完成后可确定正极材料一次颗粒的粒径，第一烧结后正极材料一次颗粒之间会团聚形成团聚物。
第一破碎是包括：将第一烧结完成后的烧结团聚物进行球磨，得到初步破碎物，再将初步破碎物进行气碎；其中，球磨的转速为4000r/min-8000r/min，球磨的时间为1.5h-2.5h，气碎的压力为5MPa-10MPa，气碎的时间为0.5h-1.5h。在该步骤可以确定二次复合颗粒的粒径D50、二次复合颗粒的比表面积和二次复合颗粒料中的正极材料一次颗粒的个数。
根据本申请实施例的正极复合材料，正极复合材料包括如上面任一项的正极材料和包覆于正极材料表面的包覆层。
包覆层可为在正极材料表面形成的一层保护层，降低正极材料与电解液的副反应，有助于材料表层结构的稳定性，提高材料的循环性能；或者包覆层为在正极材料表面形成的热阻隔层，降低材料热扩散的速率，提升材料的安全性等。
在一些实施例中，包覆层在正极复合材料中的质量占比为300ppm-900ppm。在该质量比范围内，包覆层可以有效的降低二次复合颗粒与电解液之间的副反应，在一定程度上可以降低材料的产气，同时包覆层还可以起到热阻隔的作用，减缓热扩散，提升材料的安全性能。另外，包覆层的用量过大，会使得在二次复合颗粒表面存在一层与本体结构不同的物质，不利于锂离子的脱出，降低二次复合颗粒中活性成分的含量，不利于提升正极材料的比容量以及倍率、低温性能；包覆层的用量过少，会使得包覆层的厚度太薄或者能包覆的二次复合颗粒表面积不足，存在裸露的二次复合颗粒与电解液接触发生副反应的现象，不利于材料性能的发挥。本申请通过实验发现，当包覆层占正极复合材料的质量比在上述范围内时，且满足上述关系式一时，正极复合材料和所做制备的电池具有较佳的性能效果。
在一些实施例中，包覆层的材质为Zr、Mn、Y、Ti、W、Al、Co、B和Mg中至少一种元素的氢氧化物和/氧化物。更优选的，包覆层的材质为Ti 3O 4、Mg(OH) 2、W 2O 3、Al 2O 3、Co(OH) 2和B(OH) 3中的至少一种。
其中包覆层可通过如下方法形成于正极材料的表面得到正极复合材料。
将正极材料和包覆材料进行混合，然后进行第二烧结，再将第二烧结完成后的混合物进行第二破碎得到正极复合材料。
根据本申请的一些实施例，第二烧结的温度为500℃-800℃，第二烧结的时间为5.0h-8.0h；第二破碎采用机械磨破碎，机械磨的转速为2000r/min-4000r/min，第二破碎的时间为0.5-1h。第二烧结的目的是将包覆材料烧结在二次复合颗粒的表面上形成包覆层，得到正极复合材料，在第二烧结过程中会有部分二次复合颗粒通过包覆材料粘接，第二破碎是将在第二烧结过程粘接到一起的二次复合颗粒分开，其目的是将二次复合颗粒之间的包覆材料分开，第二破碎采用上述范围的参数时不会影响二次复合颗粒的粒径。
本申请还提供一种电池，电池包括正极片，正极片包括集流体以及设置于集流体上的正极活性层，正极活性层包括如上面任一项的正极复合材料。其中正极活性层是由正极浆料涂覆在集流体上形成的涂层。
本申请中正极片包括上述的正极复合材料，使得正极片的极片压实密度在3.5g/mm 3以 上，极片压后取向003峰强度和110峰强度比值较低，说明取向性越弱，不容易在充放电时膨胀。
电池包括如上面的正极片，可降低电池阻抗和电池在高温储存的厚度变化率，以及可提高电池循环500次的容量保持率，提高电池的电性能。
在一些实施例中，正极浆料还包括导电剂和粘结剂，正极复合材料、导电剂以及粘结剂的质量比为100∶(0.5-2)∶(0.5-2)。或者说正极活性层包括正极复合材料、导电剂以及粘结剂，正极复合材料、导电剂以及粘结剂的质量比为100∶(0.5-2)∶(0.5-2)。
导电剂包括碳管、炭黑以及石墨烯中的至少一种，优选的，导电剂包括碳管、炭黑以及石墨烯三种。
粘结剂包括由偏氟乙烯与含活性基团的乙烯烃化合物共聚得到的第一共聚物和由偏氟乙烯与三氟氯乙烯共聚得到的第二共聚物。其中在第一共聚物中，偏氟乙烯和含活性基团的乙烯烃化合物的质量比为(85.00-99.99)∶(0.01-15.00)，活性基团包括羧基、环氧基、羟基和磺酸基中的至少一种；在第二共聚物中，偏氟乙烯和三氟氯乙烯的质量比为(85.00-99.05)∶(0.05-15.00)。
为了更好的说明本申请的技术方案，下面结合多个具体实施例进行说明。
实施例
一种正极材料的制备：
步骤S100，将镍钴锰前驱体和第二前驱体混合并在辊道窑中进行预烧结，在本实施例中镍钴锰前驱体选用Ni 0.7Co 0.1Mn 0.2(OH) 2，第二前驱体选用氢氧化锂，预烧结的温度为200℃-500℃，预烧结的时间为4h-6h。
步骤S200，将所得预烧结混合物进行第一烧结，在完成第一烧结后进行第一破碎，得到正极材料，第一烧结依次包括第一升温段、第一恒温段、第二升温段、第二恒温段以及降温段；第一升温段的温度为200℃-800℃，第一升温段的时间为1.5h-3.5h；第一恒温段的温度为700℃-800℃，第一恒温段的时间为5.0h-8.0h；第二升温段的温度为800℃-1100℃，第二升温段的时间为2.0h-3.5h；第二恒温段的温度为1000℃-1100℃，第二恒温子段的时间为8.0h-10.0h；降温段包括第一降温子段和第二降温子段，第一降温子段的温度为1100℃-600℃，第一降温子段的时间为2.5-4.0h；第二降温子段的温度为600℃-200℃，第二降温子段的时间为0.5-2.0h；第一破碎包括将第一烧结完成后的烧结团聚物进行球磨，得到初步破碎物，再将初步破碎物进行气碎；其中，球磨的转速为4000r/min-8000r/min，球磨的时间为1.5h-2.5h；气碎的压力为5MPa-10MPa，气碎的时间为0.5h-1.5h。
其中，所得正极材料包括多个二次复合颗粒，每个二次复合颗粒包括多个正极材料一次颗粒，正极材料一次颗粒为层状结构正极材料，化学式为LiNi 0.7Co 0.1Mn 0.2。
按照上述实施例方法，调整制备参数得到不同的正极材料，并对正极材料的粒径D50、二次复合颗粒的比表面积以及二次复合颗粒中正极材料一次颗粒的个数及其粒径D50进行测试，结果汇总在表1，其中a表示正极材料一次颗粒的粒径D50的值，单位为μm；b表 示二次复合颗粒的粒径D50的值，单位为μm；c表示二次复合颗粒的比表面积的值，单位为m 2/g；d表示二次复合颗粒中正极材料一次颗粒的个数。各项目的测试方法如下：
正极材料一次颗粒的粒径D50测试方法为：利用5000倍下的CP-SEM图片，统计300个左右的正极材料一次颗粒的长边尺寸，做数据的统计分布，得出正极材料一次颗粒的粒径D50。
二次复合颗粒的粒径D50的测试方法为：测试设备为激光粒度仪，参考型号为马尔文2000/3000。测试方法是：在去离子水中进行分散，超声10min；进行测试，得到二次复合颗粒的粒径D50。
二次复合颗粒的比表面积的测试方法为：采用气体吸附方法，多点位置测试，测试标准为ISO-9277/GB/T19587-2004。
二次复合颗粒中的正极材料一次颗粒的个数的测试方法为：利用EBSD(背散射电子衍射技术)测试二次复合颗粒内部中正极材料一次颗粒的各种取向，不同的正极材料一次颗粒的取向不同，在EBSD下显示不同的颜色，在10K下的EBSD的图片中，计算10μm×10μm的单位面积内二次复合颗粒中的正极材料一次颗粒的平均个数，再根据一个二次复合颗粒的面积来得到一个二次复合颗粒中正极材料一次颗粒的平均个数。
正极复合材料的制备：将制备得到的正极材料和包覆材料进行混合，然后进行第二烧结，再将第二烧结完成后的混合物进行第二破碎得到正极复合材料。在本实施例中包覆材料选用Ti 3O 4，包覆材料在所形成的正极复合材料中的含量为300-900ppm。第二烧结的温度为500℃-800℃，第二烧结的时间为5.0h-8.0h；第二破碎采用机械磨破碎，机械磨的转速为2000r/min-4000r/min，第二破碎的时间为0.5-1h。
正极浆料的制备：将制备得到的正极复合材料与导电剂、粘结剂按照质量比为100∶1.2∶1.2混合制备得到正极浆料，其中导电剂为包括碳管、炭黑以及石墨烯三种，碳管、炭黑以及石墨烯的质量比为0.6∶0.5∶0.3，粘结剂为由偏氟乙烯与含活性基团的乙烯烃化合物共聚得到的第一共聚物和由偏氟乙烯与三氟氯乙烯共聚得到的第二共聚物组成，第一共聚物和第二共聚物的摩尔比为1∶1，在第一共聚物中，偏氟乙烯和含活性基团的乙烯烃化合物的质量比为95.00∶5.00，活性基团包括羧基；在第二共聚物中，偏氟乙烯和三氟氯乙烯的质量比为96.00∶4.00。
将所制备的正极浆料进行性能测试，包括极片压实密度测试、极片压后取向测试、电池阻抗测试、循环性能测试以及储存性能测试。
其中，极片压实密度测试方法为：将各实施例中制备的正极浆料涂布于极片上形成未压正极极片，将未压正极极片制成40*100mm大小，利用大野压片机进行压片，根据极片的面密度和极片压后的厚度，计算极片压实密度。
极片压后取向测试方法为：按照JY/T 009-1996多晶体X射线衍射方法通则进行测定；分别采用(003)和(110)的峰强比值来表征。
电池阻抗测试方法为：将制备的各正极材料制成对应的电池，将电池调至60％SOC，采用电流3C，充放电时间为10s的测试方法，测试电池的DCIR；将电池的DCIR的数值与电 池1/3C放电容量的乘积作为电池阻抗的表征。
循环性能测试方法为：将制备的各正极材料制成对应的电池，测试方法为：温度条件：45±5℃；充电：1C恒流充电至4.2V；放电：1C恒流放电至2.5V；循环500次后，以第一次循环的放电容量C1作为参考，计算容量保持率，在表2中记为循环45℃-C500。
储存性能测试方法为：将制备的各正极材料制成对应的电池，电池按照0.2C恒流充电至4.2V，室温下放置2h，记录电池初始厚度；将电池置于60℃的恒温柜存放28D，记录储存后的厚度，计算厚度变化，在表2中记为60-28D厚度变化率。
表1
Figure PCTCN2021087569-appb-000001
其中对比例1-3是按照不同于上述实施例的方法制备得到二次复合颗粒，且二次复合颗 粒中的a、b、c、d值如表1所示。
本申请还增加了对比例4-对比例14。
在对比例4中：对比例4的制备方法与实施例1制备方法大致相同，不同的是，在第一烧结中不采用升温段和恒温段交叉烧结的方法，而是直接升温到1000℃-1100℃烧结，烧结时间与实施例1烧结的时间相同。
在对比例5中：对比例5的制备方法与实施例1制备方法大致相同，不同的是，在第一烧结中不采用升温段和恒温段交叉烧结的方法，而是包括三个烧结段，第一烧结段温度为400-600℃，烧结4h，第二烧结段温度为600-700烧结4h，第三烧结段温度为700-900℃，烧结13h。
在对比例6中：对比例6的制备方法与实施例1制备方法大致相同，不同的是，采用一个升温段和一个恒温段进行烧结，其中该升温段的温度为200℃-1100℃，升温段的时间与实施例1中第一升温段和第二升温段的时间总和相同，恒温段的温度为1000℃-1100℃，恒温段的时间为与实施例1中第一恒温段和第二恒温段的时间总和相同。
在对比例7中：对比例7的制备方法与实施例1制备方法大致相同，不同的是，降温段的降温时间为1h，即对比例7的降温时间远小于实施例1的降温时间。
在对比例8中：对比例8的制备方法与实施例1制备方法大致相同，不同的是，在第一破碎过程中球磨的转速为2000r/min，小于实施例1的球磨转速。
在对比例9中：对比例9的制备方法与实施例1制备方法大致相同，不同的是，在第一破碎过程中球磨的转速为10000r/min，大于实施例1的球磨转速。
在对比例10中：对比例10的制备方法与实施例1制备方法大致相同，不同的是，气碎的压力为3MPa，小于实施例1的气碎压力。
在对比例11中：对比例10的制备方法与实施例1制备方法大致相同，不同的是，气碎的压力为20MPa，大于实施例1的气碎压力。
在对比例12中：对比例12的制备方法与实施例1制备方法大致相同，不同的是，在步骤S300中添加的包覆材料的用量为2000ppm。
在对比例13中：制备小颗粒材料，小颗粒材料是由1-3个正极材料一次颗粒组成，正极材料一次颗粒为LiNi 0.7Co 0.1Mn 0.2。
在对比例14中：制备二次颗粒材料，二次颗粒材料是由多个正极材料一次颗粒组成，二次颗粒材料的粒径D50为50μm，即二次颗粒材料中具有非常多个正极材料一次颗粒，正极材料一次颗粒为LiNi 0.7Co 0.1Mn 0.2。
将上述实施例1-实施例9以及对比例1-对比例14制备得到的正极材料进行性能测试，性能效果数据如表2所示。
表2
Figure PCTCN2021087569-appb-000002
Figure PCTCN2021087569-appb-000003
从表2实验数据可以看出，实施例1-实施例9所制备的正极材料具有较优的性能效果，在极片压实密度方面，最高能达到3.70g/cm 3，极片压实密度值越大，说明正极材料的能量密度越高；在极片压后取向方面，003峰/110峰强度的比值最低能达到25，比值越小说明正极材料的取向性越差，越有利于减缓极片在充放电时的膨胀程度；在电池阻抗方面，最小能达到50mΩ，电池阻抗值越小，说明书电池导电性越好；在循环性能方面，循环45℃-C500的值(容量保持率)最高有95％，最低也能达到85％，这说明具有较好的循环性能；在储存性能方面，60℃-28D厚度变化率最低能达到6％，厚度变化率值越低，说明电池的储存性能越佳，越稳定。
从对比例1可以看出，关系式一的值不在本申请的范围内，且二次复合颗粒中的正极材 料一次颗粒的个数太多时，极片压片以及循环过程中，正极材料一次颗粒之间会发生破碎，进而更一步导致新的界面出现，电池性能劣化，对比例1的极片压后取向、循环性能以及储存性能均较差。
从对比例2可以看出，关系式一的值不在本申请的范围内，且正极材料一次颗粒的粒径D50太大时，直接影响锂离子的扩散路径的长短，导致材料的容量发挥偏低，电池阻抗增加，循环性能以及储存性能降低，对比例2的循环性能以及储存性能均较差。
从对比例3可以看出，关系式一的值不在本申请的范围内，且二次复合颗粒的比表面积过大、二次复合颗粒中的正极材料一次颗粒的个数太多时，二次复合颗粒的比表面积过大会导致次二次复合颗粒和电解液副反应增加，产气严重，电池的循环性能受到影响；二次复合颗粒中的正极材料一次颗粒的个数太多时极片压片以及循环过程中，正极材料一次颗粒之间会发生破碎，进而更一步导致新的界面出现，电池性能劣化，对比例3的极片压实密度、极片压后取向、电池阻抗、循环性能以及储存性能均较差。
从对比例4可以看出，不采用温度分段烧结以及升温段和恒温段交叉烧结的方法，所制备的二次复合颗粒的各项性能数据比实施例1-实施例9的数据稍差，但比对比例1-对比例3的数据要好，这说明采用本申请的第一烧结的方法有利于形成满足本申请关系式一的正极材料。
从对比例5可以看出，虽然采用温度分段烧结方法，但是没有采用升温段和恒温段交叉烧结的方法，所制备的二次复合颗粒的各项性能数据比实施例1-实施例9的数据稍差，但比对比例1-对比例3的数据要好，这说明采用本申请的第一烧结的方法有利于形成满足本申请关系式一的正极材料。
从对比例6和对比例7可以看出，第一烧结在本申请的范围有利于形成满足本申请关系式一的正极材料，在对比例6中，仅采用一次升温和一次恒温使得锂源和前驱体材料在前期的热分解过程不充分，导致其水分或者CO 2排除不充分，烧结过程中正极材料不能充分结晶。在对比例7中降温速度太快，会使得二次复合颗粒内部会残存大量的应力，导致材料在急剧降温后，材料颗粒内部应力很大，正极材料一次颗粒和二次复合颗粒都会发生不同程度的破碎，同时在后续的使用过程中、循环过程中发生裂纹，影响材料的性能。
从对比例8和对比例9可以看出，球磨速度在本申请的范围有利于形成满足本申请关系式一的正极材料，球磨速度过快会导致二次复合颗粒过小，球磨速度过慢会导致二次颗粒复合过大，影响材料的性能。
从对比例10和对比例11可以看出，气碎压力在本申请的范围有利于形成满足本申请关系式一的正极材料，气碎压力过小会导致二次颗粒复合太大，且二次复合颗粒粒径分布变宽，气碎压力过大会导致二次复合颗粒太小，且二次复合颗粒粒径分布变宽，细粉增多，影响材料的性能。
从对比例12可以看出，在正极材料表面包覆较多的包覆材料，会导致材料充放电过程中脱嵌锂困难，对比例12的电池阻抗增加，但循环性能和储存性能仍比对比例1-5的效果要好。
从对比例13和对比例14可以看出，目前现有小颗粒材料和二次颗粒材料的性能没有满足本申请的关系式一的情况下，其性能效果较差。
尽管已经示出和描述了本申请的实施例，本领域的普通技术人员可以理解：在不脱离本申请的原理和宗旨的情况下可以对这些实施例进行多种变化、修改、替换和变型，本申请的范围由权利要求及其等同物限定。

Claims (10)

  1. 一种正极材料，其特征在于，所述正极材料包括多个二次复合颗粒，每个所述二次复合颗粒包括多个正极材料一次颗粒；所述二次复合颗粒满足以下关系式一：
    0.9≤0.1d/a+b*c≤20(关系式一)
    其中，所述a表示所述正极材料一次颗粒的粒径D50的值，单位为μm；所述b表示所述二次复合颗粒的粒径D50的值，单位为μm；所述c表示所述二次复合颗粒的比表面积的值，单位为m 2/g；所述d表示所述二次复合颗粒中所述正极材料一次颗粒的个数。
  2. 如权利要求1所述的正极材料，其特征在于，所述a的取值范围为：0.5≤a≤3.5，所述b的取值范围为：3≤b≤12，所述c的取值范围为：0.3≤c≤1.2，所述d的取值范围为：1≤d≤50。
  3. 如权利要求1-2中任一项所述的正极材料，其特征在于，所述正极材料一次颗粒为LiNi xCo yM z，所述x的取值范围为：0.33≤x≤0.98，所述y的取值范围为：0.01≤y≤0.33，所述z的取值范围为：0.01≤z≤0.33，且x+y+z＝1，所述M为Mn、Al、Zr、Ti、Y、Sr和W中的至少一种。
  4. 一种如权利要求1-3任一项所述正极材料的制备方法，其特征在于，所述正极材料的制备方法包括：
    将第一前驱体和第二前驱体混合并进行预烧结；
    将所得预烧结混合物进行第一烧结，在第一烧结完成后进行第一破碎，得到正极材料，所述正极材料包括多个二次复合颗粒，每个所述二次复合颗粒包括多个正极材料一次颗粒。
  5. 如权利要求4所述的正极材料的制备方法，其特征在于，所述二次复合颗粒满足以下关系式一：
    2.5≤0.1d/a+b*c≤9(关系式一)
    其中，所述a表示所述正极材料一次颗粒的粒径D50的值，单位为μm；所述b表示所述二次复合颗粒的粒径D50的值，单位为μm；所述c表示所述二次复合颗粒的比表面积的值，单位为m 2/g；所述d表示所述二次复合颗粒中所述正极材料一次颗粒的个数。
  6. 如权利要求4-5中任一项所述的正极材料的制备方法，其特征在于，所述第一烧结依次包括第一升温段、第一恒温段、第二升温段、第二恒温段以及降温段；
    所述第一升温段的温度为200℃-800℃，所述第一升温段的时间为1.5h-3.5h；所述第一恒温段的温度为700℃-800℃，所述第一恒温段的时间为5.0h-8.0h；所述第二升温段的温度为800℃-1100℃，所述第二升温段的时间为2.0h-3.5h；所述第二恒温段的温度为1000℃-1100℃，所述第二恒温段的时间为8.0h-10.0h；
    所述降温段包括第一降温子段和第二降温子段，所述第一降温子段的温度为1100℃-600℃，所述第一降温子段的时间为2.5-4.0h；所述第二降温子段的温度为600℃-200℃，所述第二降温子段的时间为0.5-2.0h。
  7. 如权利要求4-6中任一项所述的正极材料的制备方法，其特征在于，所述第一破碎是包括：将第一烧结完成后的烧结团聚物进行球磨，得到初步破碎物，再将所述初步破碎物进行气碎；其中，所述球磨的转速为4000r/min-8000r/min，所述球磨的时间为1.5h-2.5h；所述气碎的压力为5MPa-10MPa，所述气碎的时间为0.5h-1.5h。
  8. 一种正极复合材料，其特征在于，所述正极复合材料包括如权利要求1-3任一项所述的正极材料和包覆于所述正极材料表面的包覆层。
  9. 如权利要求8所述的正极复合材料，其特征在于，所述包覆层在所述正极复合材料中的质量占比为300ppm-900ppm。
  10. 一种电池，其特征在于，所述电池包括正极片，所述正极片包括集流体以及设置于所述集流体上的正极活性层，所述正极活性层包括如权利要求8或9所述的正极复合材料。
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101584062A (zh) * 2006-12-26 2009-11-18 株式会社三德 非水电解质二次电池用正极活性物质、正极以及二次电池
JP2016139569A (ja) * 2015-01-29 2016-08-04 住友金属鉱山株式会社 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池
CN110265631A (zh) * 2018-06-27 2019-09-20 宁德时代新能源科技股份有限公司 一种三元正极材料及其制备方法和锂离子电池
WO2020085731A1 (ko) * 2018-10-26 2020-04-30 주식회사 엘지화학 이차전지용 양극 활물질, 그 제조방법 및 이를 포함하는 리튬 이차전지
CN111384371A (zh) * 2018-12-29 2020-07-07 宁德时代新能源科技股份有限公司 一种抗压的正极活性材料及电化学储能装置

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000133246A (ja) * 1998-10-30 2000-05-12 Hitachi Maxell Ltd 非水二次電池
CN110637384B (zh) * 2017-08-31 2022-09-30 松下知识产权经营株式会社 非水电解质二次电池用正极活性物质、非水电解质二次电池用正极和非水电解质二次电池
CN110890525B (zh) * 2018-09-11 2023-08-11 艾可普罗 Bm 有限公司 用于锂二次电池的正极活性材料及包括其的锂二次电池
CN109742344B (zh) * 2018-12-21 2022-07-19 贵州振华新材料股份有限公司 低游离锂的氧化铝包覆高镍正极材料、制法和应用

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101584062A (zh) * 2006-12-26 2009-11-18 株式会社三德 非水电解质二次电池用正极活性物质、正极以及二次电池
JP2016139569A (ja) * 2015-01-29 2016-08-04 住友金属鉱山株式会社 非水系電解質二次電池用正極活物質とその製造方法、および非水系電解質二次電池
CN110265631A (zh) * 2018-06-27 2019-09-20 宁德时代新能源科技股份有限公司 一种三元正极材料及其制备方法和锂离子电池
WO2020085731A1 (ko) * 2018-10-26 2020-04-30 주식회사 엘지화학 이차전지용 양극 활물질, 그 제조방법 및 이를 포함하는 리튬 이차전지
CN111384371A (zh) * 2018-12-29 2020-07-07 宁德时代新能源科技股份有限公司 一种抗压的正极活性材料及电化学储能装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4184615A4 *

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