WO2023169064A1 - 单晶型多元正极材料及其制备方法和锂离子电池 - Google Patents

单晶型多元正极材料及其制备方法和锂离子电池 Download PDF

Info

Publication number
WO2023169064A1
WO2023169064A1 PCT/CN2022/144086 CN2022144086W WO2023169064A1 WO 2023169064 A1 WO2023169064 A1 WO 2023169064A1 CN 2022144086 W CN2022144086 W CN 2022144086W WO 2023169064 A1 WO2023169064 A1 WO 2023169064A1
Authority
WO
WIPO (PCT)
Prior art keywords
cathode material
single crystal
sintering
crystal multi
component
Prior art date
Application number
PCT/CN2022/144086
Other languages
English (en)
French (fr)
Inventor
胡贻僧
李珊珊
宋顺林​
刘亚飞
陈彦彬
Original Assignee
北京当升材料科技股份有限公司
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 北京当升材料科技股份有限公司 filed Critical 北京当升材料科技股份有限公司
Priority to EP22930683.2A priority Critical patent/EP4306687A1/en
Priority to JP2023560160A priority patent/JP2024511223A/ja
Publication of WO2023169064A1 publication Critical patent/WO2023169064A1/zh
Priority to US18/497,404 priority patent/US11955635B1/en

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
    • C30B29/10—Inorganic compounds or compositions
    • C30B29/16—Oxides
    • C30B29/22—Complex oxides
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B1/00—Single-crystal growth directly from the solid state
    • C30B1/10—Single-crystal growth directly from the solid state by solid state reactions or multi-phase diffusion
    • C—CHEMISTRY; METALLURGY
    • C30—CRYSTAL GROWTH
    • C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
    • C30B1/00—Single-crystal growth directly from the solid state
    • C30B1/12—Single-crystal growth directly from the solid state by pressure treatment during the growth
    • 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
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • 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
    • 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
    • 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

Definitions

  • the present invention relates to the field of cathode material preparation, specifically to single crystal multi-component cathode materials and their preparation methods and lithium ion batteries.
  • Lithium-ion batteries have outstanding advantages such as high voltage, high energy density, good cycle performance, small self-discharge, and no memory effect.
  • the cathode material plays a decisive role in the capacity, performance and cost of the battery.
  • nickel-cobalt-manganese multi-component materials have high gram capacity and good cycle stability. Multi-component cathode materials are divided into agglomerated type and single crystal type according to the state of particle existence.
  • the spherical particles of the agglomerated multi-component cathode material are easily broken when rolled, and the electrolyte will penetrate between the broken particles, causing a series of side effects, thus posing a greater challenge to the processing technology. Designing the cathode material into a more stable single crystal structure can effectively avoid the above problems.
  • the sintered single crystal particles have obvious edges and corners, poor roundness and regularity. Irregular particles are more likely to break during the pole piece rolling process, or The separator is pierced during assembly, causing the battery cycle performance to deteriorate or even dive.
  • the use of pure oxygen sintering not only increases the processing cost, but also because the lithium salt will melt into the particles under the oxygen atmosphere.
  • the primary particles formed in the heating section are relatively round and regular, it is difficult to fuse between the particles in the constant temperature section, resulting in It is difficult for the particles to grow into single crystals, or the crystal particles formed have severe adhesion between particles, poor independence, and even maintain a precursor-like morphology.
  • the purpose of the present invention is to overcome the existing problems in the prior art that single crystal cathode materials have uneven grain sizes, easy adhesion between particles, and poor roundness and regularity of single crystals.
  • the first aspect of the present invention provides a single-crystal multi-element cathode material.
  • the length of the longest diagonal and the shortest diagonal of the single-crystal particles of the single-crystal multi-element cathode material measured by SEM are defined.
  • the ratio of the lengths is the roundness R, and R ⁇ 1;
  • a second aspect of the present invention provides a method for preparing a single crystal multi-component cathode material.
  • the preparation method includes:
  • the first sintering includes a temperature rising stage I and a constant temperature stage I carried out in sequence, the temperature rising stage I is carried out in an oxygen atmosphere, and the constant temperature stage I is carried out in an air atmosphere;
  • the temperature of the second sintering is not higher than the temperature of the first sintering.
  • a third aspect of the present invention provides a single crystal multi-component cathode material prepared by the preparation method described in the second aspect.
  • a fourth aspect of the present invention provides a lithium-ion battery, which contains the single-crystal multi-element positive electrode material described in the first or third aspect.
  • the preparation method provided by the present invention starts from the perspective of optimizing the sintering process.
  • an oxygen atmosphere is used in the heating section and an air atmosphere is used in the constant temperature section to optimize the single crystal morphology, combined with the second sintering process.
  • the single-crystal multi-element cathode material obtained by sintering meets specific roundness and uniformity. Its single-crystal particles have a more rounded and regular shape, uniform size, less agglomeration and less adhesion, which enables it to be pressed during the process of making electrodes. It has a higher solid density and is less likely to break and fall off during processing and battery cycling, thereby improving the energy density, rate performance and cycle stability of the battery.
  • single crystal cathode materials have better performance than non-single crystal cathode materials in terms of cycle life, rate performance, stability, safety and processability.
  • Figure 1 is an SEM image of the single crystal multi-component cathode material prepared in Example 1 of the present invention
  • Figure 2 is an SEM image of the single crystal multi-component cathode material prepared in Example 2 of the present invention.
  • Figure 3 is an SEM image of the single crystal multi-component cathode material prepared in Example 3 of the present invention.
  • Figure 4 is an SEM image of the single crystal multi-component cathode material prepared in Comparative Example 1 of the present invention
  • Figure 5 is an SEM image of the single crystal multi-component cathode material prepared in Comparative Example 2 of the present invention.
  • Figure 6 is an SEM image of the single crystal multi-component cathode material prepared in Comparative Example 3 of the present invention.
  • Figure 7 is an SEM image of the single crystal multi-component cathode material prepared in Comparative Example 4 of the present invention.
  • first and second do not represent the order, nor do they limit each material or operation. They are only used to distinguish each material or operation.
  • the "first” and “second” in “first sintering” and “second sintering” are only for differentiation to indicate that these are not the same sintering operation.
  • the room temperature mentioned in the present invention refers to 25 ⁇ 2°C.
  • a first aspect of the present invention provides a single-crystal multi-component cathode material.
  • the ratio of the length of the longest diagonal to the length of the shortest diagonal of the single-crystal particles of the single-crystal multi-component cathode material measured by SEM is defined as Roundness R, and R ⁇ 1;
  • the product of is 1.20-1.40.
  • the quality of the single crystal structure directly affects the electrochemical performance of the cathode material.
  • the inventor of the present invention found that the single crystal multi-element cathode material that meets the above specific parameter limitations has The shape is round and regular, the particle size is uniform, and there is less agglomeration and adhesion, which enables the positive electrode material to be compacted at a higher density during the process of making the electrode, and is less likely to fragment and fall off during processing and battery cycling, thus benefiting Improve battery energy density and cycle stability.
  • the ratio of the length of the longest diagonal to the length of the shortest diagonal measured by SEM of the single crystal particles of the single crystal multi-component cathode material is defined as the roundness R, and R ⁇ 1.
  • the rounded and regular single-crystal particles help prevent the cathode material from breaking during the rolling process of the pole pieces, and prevent the irregular corners of the cathode material from piercing the separator during battery assembly, which helps improve the safety performance and cycle performance of the battery.
  • R is the statistical result obtained by randomly selecting 300 single crystal particles as samples in the SEM image.
  • R is 1-1.2.
  • the single crystal particles using the single crystal multi-component cathode material of the above preferred embodiment have a more rounded and regular shape, which is conducive to further improving the safety performance and cycle performance of the battery.
  • the particle size corresponding to 10% of the volume distribution of the single crystal particles of the single crystal multi-component cathode material obtained from the particle size test is D 10
  • the particle size corresponding to 50% of the volume distribution is D 50
  • the volume distribution The particle size corresponding to 90% is D 90
  • the uniformity of the single crystal multi-element cathode material is defined as K 90
  • K 90 (D 90 -D 10 )/D 50
  • the product of K 90 and R is 1.20- 1.40.
  • the product of K 90 and R is 1.25-1.35.
  • the single-crystal multi-component cathode material using the above preferred embodiment has high capacity and cycle retention rate, and is conducive to further increasing the compaction density of the cathode material.
  • the particle size D 10 of the single crystal multi-component cathode material is 1.5-2.5 ⁇ m.
  • the particle size D 50 of the single crystal multi-component cathode material is 3-5 ⁇ m.
  • the particle size D 90 of the single crystal multi-component cathode material is 6-8 ⁇ m.
  • the particle size test is carried out using the Hydro 2000mu model laser particle size analyzer of Marvern Company.
  • the smaller the value of K 90 the better the uniformity of the single crystal particles; the larger the value of K 90 , the worse the uniformity of the single crystal particles.
  • K90 is 1.18-1.25, preferably 1.20-1.22.
  • the uniformity of the single crystal particles is better, which is conducive to increasing the gradation and improving the compaction density of the material.
  • the single crystal multi-component cathode material has the structure shown in Formula I:
  • G is one or more of Ti, W, V, Ta, Zr, La, Ce, Er, Sr, Si, Al, B, Mg, Co, F and Y;
  • M is Sr, F, B, One or more of Al, Nb, Co, Mn, Mo, W, Si, Mg, Ti and Zr;
  • G is one or more of Ti, W, Zr, Sr, Si, Al, B and F; and/or M is Sr, F, B, Al, W, Si and One or more of Ti.
  • Adopting the above preferred embodiments is beneficial to further improving the energy density, rate performance and cycle stability of the battery.
  • the agglomeration rate of the single-crystal multi-component cathode material is defined as B.
  • Any 300 single crystal particles of the single-crystal multi-component cathode material measured by SEM have an agglomerated morphology.
  • the single crystal multi-component cathode material using the above preferred embodiment has a small agglomeration rate of single crystal particles, a high degree of single crystallization, less adhesion, and is not easy to fall off or fragment under high voltage or during long cycles, which is conducive to further improvement. Energy density, rate performance and cycle stability of the battery.
  • the average value of the longest diagonal length and the shortest diagonal length of any 300 single crystal particles measured by SEM of the single crystal multi-element cathode material is defined as
  • the grain size is P 50
  • P 50 is 1.5-3.0 ⁇ m, preferably 2.0-2.4 ⁇ m. If the value of P 50 is too large, it will increase the transmission distance of lithium ions inside the cathode material, affecting the capacity. If the value of P 50 is too small, it will cause the material to agglomerate and even fail to form a single crystal material, affecting the cycle performance of the material. .
  • Using the single-crystal multi-component cathode material in the above preferred embodiment is beneficial to further improving the capacity and cycle performance of the single-crystal multi-component cathode material.
  • the single crystal multi-element cathode material adopts a secondary sintering process during the preparation process.
  • an oxygen atmosphere is used in the heating section and an air atmosphere is used in the constant temperature section, so that the single crystal particle morphology is more rounded and regular. , more uniform size, less agglomeration and adhesion, and higher compaction density, which is beneficial to improving the energy density, rate performance and cycle stability of the battery.
  • a second aspect of the present invention provides a method for preparing a single crystal multi-component cathode material.
  • the preparation method includes:
  • the first sintering includes a temperature rising stage I and a constant temperature stage I carried out in sequence, the temperature rising stage I is carried out in an oxygen atmosphere, and the constant temperature stage I is carried out in an air atmosphere;
  • the temperature of the second sintering is not higher than the temperature of the first sintering.
  • the fusion stage is a constant temperature section with a higher temperature, that is, the lithium source and the fine primary particles further react, so that The process of fusion into large particles.
  • the temperature-raising stage I of the first sintering By using an oxygen atmosphere in the temperature-raising nucleation stage of the reaction between the nickel-cobalt-manganese precursor and the lithium source (the temperature-raising stage I of the first sintering), the primary particles formed from the fiber are made more plump and round, and in the growth stage of the constant-temperature sintering (the first sintering stage I)
  • the constant temperature stage I) uses an air atmosphere to make it easier for single crystal particles to fuse to form large single crystal particles.
  • the finished particles of the cathode material are more rounded and regular, and the obtained single crystal polymorphic
  • the cathode material has a rounded and regular morphology, uniform particle size, and less agglomeration and adhesion. It has the characteristics of high compaction density, good rate performance and excellent cycle performance.
  • the nickel-cobalt-manganese precursor in step (1), can be a nickel-cobalt-manganese precursor known in the art and suitable for preparing cathode materials. There is no particular limit to this, and they can all be used. The invention object of the present invention is achieved to a certain extent.
  • the nickel-cobalt-manganese precursor is selected from oxides and/or hydroxides containing nickel, cobalt and manganese.
  • the lithium source in step (1), can be a lithium source known in the art and suitable for preparing cathode materials. There is no special limit to this, and all of them can achieve this to a certain extent.
  • the lithium source is selected from lithium carbonate and/or lithium hydroxide.
  • the amount of the lithium source satisfies: 1.02 ⁇ [n(Li)]/[n(Ni)+n(Co) +n(Mn)] ⁇ 1.06.
  • the mixed raw materials further include additives, and the additives are selected from compounds containing G, preferably oxides, hydroxides, and carbonic acids containing G. At least one of salts and fluorides, more preferably at least one of zirconium oxide, strontium carbonate, strontium hydroxide, silicon dioxide, aluminum oxide, aluminum hydroxide, tungsten trioxide, titanium oxide, aluminum fluoride and boron oxide.
  • G can be selected with reference to the above, and will not be described again here.
  • the additive is beneficial to the formation of single crystallization of the material, reducing internal resistance and improving the cycle stability of the material.
  • step (1) preferably, in step (1), according to the stoichiometric ratio, the amount of the additive calculated as G element satisfies: 0.0001 ⁇ [n(G)]/[n(Ni)+ n(Co)+n(Mn)] ⁇ 0.005.
  • the temperature rising stage I is carried out in an oxygen atmosphere, through the temperature rising nucleation stage of the reaction between the nickel cobalt manganese precursor and the lithium source (that is, the temperature rising stage I of the first sintering )
  • Using an oxygen atmosphere can make the primary particles formed by fibers more plump and round.
  • the conditions of the temperature rise stage I also include: the temperature rise time is 2-10 h, preferably 6-8 h.
  • the temperature is increased to the constant temperature of the constant temperature stage I through the above heating time.
  • the constant temperature stage I is performed in an air atmosphere.
  • the constant temperature stage I of the first sintering the single crystal particles can be fuse more easily to form large single crystal particles.
  • the conditions of the constant temperature stage I also include: the constant temperature temperature is 600-1100°C, preferably 900-1000°C; the constant temperature time is 6-12h, preferably for 8-10h.
  • the median particle size D 50 of the nickel cobalt manganese precursor is 3-5 ⁇ m.
  • the median particle size D′ 50 of the single crystal cathode material process product is 3-5 ⁇ m.
  • the median particle size D 50 of the nickel cobalt manganese precursor and the median particle size D′ 50 of the single crystal cathode material process product satisfy Formula II :
  • Adopting the above preferred embodiment is beneficial to obtain a single crystal multi-element cathode material whose particle size D 10 , D 50 , D 90 and uniformity K 90 of the single crystal particles meet the above requirements.
  • the median particle size D′ 50 of the obtained single crystal cathode material process product meets the above requirements.
  • the equipment used in the crushing process is selected from soybean milk. At least one of machine, jaw crusher, roller, colloid mill, mechanical mill and airflow mill.
  • the single crystal cathode material process product and the coating agent are mixed first, and then the resulting mixture is subjected to the second sintering; the coating
  • the coating agent is selected from compounds containing M, preferably at least one of oxides, hydroxides, carbonates and fluorides containing M, more preferably strontium carbonate, strontium hydroxide, silicon dioxide, alumina, At least one of aluminum hydroxide, tungsten trioxide, titanium oxide, aluminum fluoride and boron oxide.
  • M can be selected with reference to the above, and will not be described again here.
  • the coating agent is beneficial to reducing free lithium and improving the cycle stability of the material in high temperature and high voltage environments.
  • step (2) preferably, in step (2), according to the stoichiometric ratio, the amount of the coating agent in terms of M elements satisfies: 0.0001 ⁇ [n(M)]/[n(Ni )+n(Co)+n(Mn)] ⁇ 0.005.
  • step (2) the second sintering is performed in an air atmosphere.
  • the second sintering includes a temperature rising stage II and a constant temperature stage II performed in sequence.
  • the conditions of the temperature rise stage II also include: the temperature rise time is 2-10 h, preferably 4-7 h.
  • the conditions of the constant temperature stage II also include: the constant temperature temperature is 500-900°C, preferably 600-800°C; the constant temperature time is 6-12h, preferably for 8-10h.
  • ⁇ P is preferably defined as the change value of the grain size of the single-crystal multi-component cathode material, in ⁇ m; ⁇ T is the temperature change value under the same sintering step, in °C; ⁇ t is the change value of the same sintering step.
  • the grain size P 50 of the obtained single crystal multi-component cathode material is P 1 ⁇ m; when the first sintering When the constant temperature of the constant temperature stage I is T 2 °C and the constant temperature time is t 2 h, the grain size P 50 of the obtained single crystal multi-element cathode material is P 2 ⁇ m, then ⁇ T is the absolute difference between T 1 and T 2 value (i.e.
  • ⁇ m), and ⁇ P ⁇ T+ ⁇ t.
  • a third aspect of the present invention provides a single crystal multi-component cathode material prepared by the preparation method described in the second aspect.
  • the single-crystal multi-component cathode material is the same as or similar to the single-crystal multi-component cathode material described in the first aspect of the present invention, and will not be described again here.
  • a fourth aspect of the present invention provides a lithium-ion battery, which contains the single-crystal multi-element positive electrode material described in the first or third aspect.
  • Morphology test obtained through the scanning electron microscope test of the S-4800 model of Hitachi HITACHI of Japan. Among them, the roundness R, the agglomeration rate B and the grain size P 50 were all obtained through the SEM image test;
  • pole piece Fully mix the single crystal multi-component cathode material, conductive carbon black and polyvinylidene fluoride (PVDF) with an appropriate amount of N-methylpyrrolidone (NMP) according to the mass ratio of 95:2:3 to form a uniform Slurry, apply the slurry on aluminum foil and dry it at 120°C for 12 hours, then stamp it into shape using a pressure of 100MPa to make a positive electrode sheet with a diameter of 15.8mm and a thickness of 3.2mm.
  • NMP N-methylpyrrolidone
  • the single-crystal multi-component The loading capacity of the positive electrode material is 15.5 mg/cm 2 .
  • the positive electrode plate, separator, negative electrode plate and electrolyte into a CR2032 button battery and let it stand for 6 hours.
  • the negative electrode uses a lithium metal sheet with a diameter of 15.8mm and a thickness of 1mm;
  • the separator uses a polypropylene microporous membrane (Celgard 2325) with a thickness of 25 ⁇ m;
  • the electrolyte uses 1mol/L LiPF 6 and ethylene carbonate (EC ) and diethyl carbonate (DEC).
  • Shenzhen Xinwell battery testing system was used to test the electrochemical performance of CR2032 button batteries.
  • the charge and discharge current density of 0.1C was 100mA/g.
  • High temperature cycle performance test Control the charge and discharge voltage range to 3.0-4.4V. At a constant temperature of 60°C, charge and discharge the button battery for 2 times at 0.1C, and then charge and discharge 80 times at 1C to evaluate the single crystal form. High-temperature cycle capacity retention rate of multi-component cathode materials.
  • Rate performance test Control the charge and discharge voltage range to 3.0-4.4V. At room temperature, charge and discharge the button battery for 2 times at 0.1C, then charge and discharge once at 0.3C, with a first discharge ratio of 0.1C. The ratio of capacity to 0.3C discharge specific capacity evaluates the rate performance of multi-component cathode materials.
  • the nickel-cobalt-manganese precursor is a hydroxide containing nickel, cobalt and manganese, and its chemical formula is shown in Table 2; the types of lithium sources and additives and the amounts of each raw material are shown in Table 1; the equipment used in the crushing process is a soymilk machine;
  • the first sintering is a heating stage I and a constant temperature stage I carried out in sequence.
  • the specific conditions are shown in Table 1;
  • the median particle size D 50 of the nickel-cobalt-manganese precursor and the median particle size D′ 50 of the single-crystal cathode material process product are shown in Table 1;
  • the second sintering is carried out in an air atmosphere; the second sintering is a heating stage II and a constant temperature stage II carried out in sequence.
  • the specific conditions are shown in Table 1; during the reaction process, the chemical formulas of each product are shown in Table 2.
  • step (1) the constant temperature of the constant temperature stage I of the first sintering and the median particle size D′ 50 of the single crystal cathode material process product are detailed in Table 1, and the rest are In the same way, a single crystal multi-component cathode material is obtained.
  • step (1) the constant temperature of the constant temperature stage I of the first sintering and the median particle size D′ 50 of the single crystal cathode material process product are detailed in Table 1, and the rest are In the same way, a single crystal multi-component cathode material is obtained.
  • the difference is that in step (1), the first sintering is performed in an air atmosphere, and the rest are the same to obtain a single crystal multi-component cathode material.
  • step (1) the first sintering is performed in an oxygen atmosphere, and the rest are the same to obtain a single crystal multi-component cathode material.
  • step (1) the first sintering is performed in an air atmosphere, and the rest are the same to obtain a single crystal multi-component positive electrode material.
  • step (1) the first sintering is performed in an oxygen atmosphere, and the rest are the same to obtain a single crystal multi-component cathode material.
  • step (1) the difference is that in step (1), the D′ 50 of the obtained single crystal cathode material process product is 3.64 ⁇ m,
  • 13.3% , all other things are the same, and a single crystal multi-element positive electrode material is obtained. Its uniformity K 90 is shown in Table 3.
  • step (1) the difference is that in step (1), the D′ 50 of the single crystal cathode material process product is 4.49 ⁇ m,
  • 6.9% , all other things are the same, and a single crystal multi-element positive electrode material is obtained. Its uniformity K 90 is shown in Table 3.
  • Amount 1 is the total molar amount of nickel cobalt manganese element in the nickel cobalt manganese precursor: the molar amount of lithium element in the lithium source: the molar amount of G element in the additive;
  • the usage amount 2 is the total molar amount of nickel cobalt manganese element in the nickel cobalt manganese precursor: the molar amount of M element in the coating agent.
  • the single-crystal multi-component cathode materials obtained in the Examples and Comparative Examples were tested respectively, including agglomeration rate B, particle size D 10 , particle size D 50 , particle size D 90 , uniformity K 90 and roundness R. The results are shown in Table 3.
  • the single crystal multi-component cathode materials obtained in the Examples and Comparative Examples were tested respectively, including the grain size P 50 and compacted density, as well as the electrochemical performance test. The results are shown in Table 4.
  • Capacity retention rate 3 is the high temperature cycle capacity retention rate.
  • the present invention exemplarily provides scanning electron microscope (SEM) images of the single crystal multi-component cathode materials obtained in Examples 1-3 and Comparative Examples 1-4, as shown in Figures 1-7 respectively. It can be seen from the figure that compared with the single crystal multi-component cathode material obtained in Example 2-3 ( Figures 2 and 3) and the single crystal multi-component cathode material obtained in Comparative Example 1-2 ( Figure 4-5), the present invention
  • the single crystal particles of the single crystal multi-component cathode material ( Figure 1) obtained in Example 1 are round and regular, and the morphology is better;
  • the grain size P 50 of the single crystal particles of the single crystal multi-component cathode material obtained in Example 2 (Fig. 2) and the single crystal multi-component cathode material obtained in Comparative Example 2 (Fig. 5) is 1.8 ⁇ m. It can be seen from the electron microscope image It is clearly seen that some particles still maintain the precursor morphology, and there are adhesion between particles. However, compared with the single crystal multi-component cathode material obtained in Comparative Example 2, Example 2 of the present invention passes through oxygen during one sintering process. The single-crystal multi-element cathode material obtained by adding air sintering process has better particle independence and regularity;
  • the crystal grain size P 50 of the single crystal particles of the single crystal multi-component cathode material obtained in Example 3 (Fig. 3) and the single crystal multi-component cathode material obtained in Comparative Example 1 (Fig. 4) is 2.6 ⁇ m, and the crystal particles are relatively large. It has good independence but poor regularity. However, compared with the single crystal multi-component cathode material obtained in Comparative Example 1, the single crystal particles of the single-crystal multi-component cathode material obtained in Example 3 of the present invention are more rounded;
  • the single crystal grain size P 50 of the single crystal particles of the single crystal multi-component cathode material obtained in Example 1 and the single crystal multi-component cathode material obtained in Comparative Examples 3 and 4 is 2.2 ⁇ m, but compared with the single crystal multi-component cathode material obtained in Comparative Examples 3 and 4.
  • the single crystal particles of the single-crystal multi-component cathode material obtained in Example 1 of the present invention have better roundness and independence.
  • the single crystal multi-element cathode material provided by the present invention has a more rounded and regular morphology, and its single crystal particles have uniform size, less agglomeration and less adhesion, and have high compaction density and good rate performance.
  • excellent cycle performance in:
  • Comparing Example 2 and Comparative Example 2, and Example 3 and Comparative Example 1 it can be seen that under the condition of air atmosphere throughout the sintering process, the growth direction of the crystal starts from the outside after the lithium source is melted and then moves to the particle surface. Therefore, a lower temperature is required to expand; however, under the condition of an oxygen atmosphere during the entire sintering process, there are more crystals and the growth starts from inside the particles, so a higher temperature is required to expand.
  • the single-crystal particles of the single-crystal multi-component cathode material obtained by the sintering method of oxygen in the heating section and air in the constant temperature section provided by the present invention have better performance. Excellent compacted density and better electrochemical performance;
  • the agglomeration rate will affect the cycle performance of the material.
  • the size of the grain size is directly related to the agglomeration rate. The larger the grain size, the smaller the agglomeration rate, and the better the cycle performance; at the same time, sintering
  • the atmosphere also has a certain impact on the agglomeration rate and cycle performance.
  • the agglomeration rate of single crystal particles prepared by the present invention's sintering method of one-time sintering oxygen combined with air is significantly lower than that of one-time sintering in single oxygen or air.
  • the corresponding cycle performance of the multi-element cathode material is: oxygen combined with air > oxygen > air.
  • the roundness index it can also be seen from the roundness index that the single crystal particles of the single crystal multi-element cathode material obtained by the method provided by the present invention are more rounded and regular, and under the same grain size, the roundness of a single oxygen atmosphere is better than that of a single air atmosphere. the roundness;
  • Example 4 and Example 5 it can be seen from Example 4 and Example 5 that the method provided by the present invention is also applicable to high-nickel products. As the nickel content increases and the cobalt content decreases, the roundness and compaction density of the multi-element cathode material can be maintained at a high level, and the electrochemical performance capacity will be significantly improved, but the rate performance and cycle performance will be correspondingly worse;

Abstract

一种单晶型多元正极材料及其制备方法和锂离子电池，所述单晶型多元正极材料的单晶颗粒由SEM测得的最长对角线的长度与最短对角线的长度的比值为圆润度R，且R≥1；所述单晶型多元正极材料的单晶颗粒的D 10、D 50和D 90满足：K 90＝(D 90-D 10)/D 50，K 90与R的乘积为1.20-1.40。所述单晶型多元正极材料的形貌更为圆润规整，且其单晶颗粒的尺寸均一、团聚少、粘连少，具有压实密度高，倍率性能好，循环性能优异的特点。

Description

单晶型多元正极材料及其制备方法和锂离子电池
相关申请的交叉引用
本申请要求2022年12月22日提交的中国专利申请202211659558.1的权益，该申请的内容通过引用被合并于本文。
技术领域
本发明涉及正极材料制备领域，具体涉及单晶型多元正极材料及其制备方法和锂离子电池。
背景技术
锂离子电池具有电压高、能量密度大、循环性能好、自放电小、无记忆效应等突出优点。正极材料作为其重要组成部分，对电池的容量、性能及成本起决定性作用。镍钴锰多元材料作为最受欢迎的锂电正极材料之一，拥有较高的克容量和良好的循环稳定性。多元正极材料按照颗粒存在状态分为团聚型和单晶型。团聚型多元正极材料在辊压时球形颗粒易破碎，电解液会从破碎的颗粒间渗透进去，导致一系列的副作用，因此对加工工艺造成了较大的挑战。而将正极材料设计成更稳定的单晶结构可以有效的避免上述问题。
现有的单晶型正极材料受制备过程中条件的限制，特别是烧结气氛的影响，单晶颗粒棱角明显、圆润度及规整度较差，或者单晶颗粒间粘连严重、独立性差，甚至仍保持类前驱体形貌。这是因为现有技术中大多采用单一气氛(空气或氧气)进行烧结。纯空气烧结虽然可以降低加工成本，但空气条件下锂盐难以熔融渗透入颗粒，而是覆盖在颗粒表面，在升温生长阶段容易形成不规则的一次颗粒；在恒温融合阶段，覆盖在颗粒表面的锂则可在表面使颗粒间融合，使颗粒迅速长大，烧结出的单晶颗粒棱角明显、圆润度及规整度较差，在极片辊压过程中不规则的颗粒更容易碎裂，或者组装时刺穿隔膜，导致电池循环性能变差甚至跳水。另一方面，采用纯氧气烧结不仅增加了加工成本，而且由于氧气气氛下锂盐会熔融到颗粒内部，在升温段虽然形成的一次颗粒较为圆润规整，但是恒温段颗粒间却难以融合，从而导致颗粒难以长大成单晶或是形成的晶体颗粒间粘连严重、独立性差，甚至仍保持类前驱体形貌。
因此提供一种形貌圆润、尺寸均一、团聚少、粘连少的单晶型正极材料及其适用于工业化生产的制备方法至关重要。
发明内容
本发明的目的是为了克服现有技术存在的单晶型正极材料的晶粒尺寸不均匀、颗粒之间易粘连以及单晶圆润度规整度差的问题。
为了实现上述目的，本发明第一方面提供一种单晶型多元正极材料，定义所述单晶型多元正极材料的单晶颗粒由SEM测得的最长对角线的长度与最短对角线的长度的比值为圆润度R，且R≥1；所述单晶型多元正极材料的单晶颗粒的D 10、D 50和D 90满足：K 90＝(D 90-D 10)/D 50，K 90与R的乘积为1.20-1.40。
本发明第二方面提供一种单晶型多元正极材料的制备方法，所述制备方法包括：
(1)将含有镍钴锰前驱体和锂源的混合物进行第一烧结，并将得到的产物进行破碎处理，得到单晶型正极材料过程品；
(2)将所述单晶型正极材料过程品进行第二烧结，得到单晶型多元正极材料；
其中，所述第一烧结包括依次进行的升温阶段I和恒温阶段I，所述升温阶段I在氧气气氛下进行，所述恒温阶段I在空气气氛下进行；
所述第二烧结的温度不高于所述第一烧结的温度。
本发明第三方面提供一种由第二方面所述的制备方法制备得到的单晶型多元正极材料。
本发明第四方面提供一种锂离子电池，所述锂离子电池含有第一方面或第三方面所述的单晶型多元正极材料。
通过上述技术方案，本发明提供的制备方法从优化烧结过程的角度出发，通过在第一烧结的过程中，升温段采用氧气气氛，恒温段采用空气气氛，以优化单晶形貌，结合第二烧结而得的单晶型多元正极材料满足特定的圆润度和均一性，其单晶颗粒的形貌更为圆润规整、尺寸均一、团聚少、粘连少，能够使得其在制作电极的过程中压实密度更高，且在加工和电池循环过程中不易发生碎裂及脱落，从而提升电池的能量密度、倍率性能和循环稳定性。
此外，单晶型正极材料相比非单晶型正极材料在循环寿命、倍率性能、稳定性、安全性和可加工性方面均有更好的表现。
附图说明
图1是本发明实施例1制得的单晶型多元正极材料的SEM图；
图2是本发明实施例2制得的单晶型多元正极材料的SEM图；
图3是本发明实施例3制得的单晶型多元正极材料的SEM图；
图4是本发明对比例1制得的单晶型多元正极材料的SEM图；
图5是本发明对比例2制得的单晶型多元正极材料的SEM图；
图6是本发明对比例3制得的单晶型多元正极材料的SEM图；
图7是本发明对比例4制得的单晶型多元正极材料的SEM图。
具体实施方式
在本文中所披露的范围的端点和任何值都不限于该精确的范围或值，这些范围或值应当理解为包含接近这些范围或值的值。对于数值范围来说，各个范围的端点值之间、各个范围的端点值和单独的点值之间，以及单独的点值之间可以彼此组合而得到一个或多个新的数值范围，这些数值范围应被视为在本文中具体公开。
在本发明中，在没有明确说明的情况下，“第一”和“第二”均不代表先后次序，也不对各个物料或者操作起到限定作用，仅是为了区分各个物料或者操作，例如，“第一烧结”和“第二烧结”中的“第一”和“第二”仅是为了区分以表示这不是同一烧结操作。
在没有特别说明的情况下，本发明所述室温是指25±2℃。
本发明第一方面提供一种单晶型多元正极材料，定义所述单晶型多元正极材料的单晶颗粒由SEM测得的最长对角线的长度与最短对角线的长度的比值为圆润度R，且R≥1；所述单晶型多元正极材料的单晶颗粒的D 10、D 50和D 90满足：K 90＝(D 90-D 10)/D 50，K 90与R的乘积为1.20-1.40。
对于单晶型正极材料而言，其单晶结构的好坏直接影响正极材料的电化学性能，本发明的发明人在研究过程中发现，满足上述特定参数限定的单晶型多元正极材料，其形貌圆润规整、颗粒尺寸均一，并且团聚少、粘连少，能够使正极材料在制作电极的过程中压实密度更高，而且在加工和电池循环过程中不易发生碎裂及脱落，从而有利于提升电池的能量密度和循环稳定性。
根据本发明的一些实施方式，定义所述单晶型多元正极材料的单晶颗粒由SEM测得的最长对角线的长度与最短对角线的长度的比值为圆润度R，且R≥1，R值越接近1，则单晶颗粒的最长对角线与最短对角线的长度越接近，表明材料的形貌越圆润规整。圆润规整的单晶颗粒有利于防止正极材料在极片辊压过程中出现碎裂，以及防止电池在组装时正极材料不规整的边角刺穿隔膜，有利于提高电池的安全性能和循环性能。本发明中，R为SEM图中随机选取300个单晶颗粒作为样本所得到的统计结果。
根据本发明的一些实施方式，优选地，R为1-1.2。采用上述优选实施方式的单晶型多元正极材料的单晶颗粒，其形貌更为圆润规整，有利于进一步提升电池的安全性能和循环性能。
根据本发明的一些实施方式，定义所述单晶型多元正极材料的单晶颗粒由粒度测试得到的体积分布10％对应的粒度为D 10，体积分布50％对应的粒度为D 50，体积分布90％对应的粒度为D 90，并定义所述单晶型多元正极材料的均一性为K 90，且K 90＝(D 90-D 10)/D 50，K 90与R的乘积为1.20-1.40。
根据本发明的一些实施方式，优选地，K 90与R的乘积为1.25-1.35。采用上述优选实施方式的单晶型多元正极材料，具有较高的容量和循环保持率，同时有利于进一步提升正极材料的压实密度。
根据本发明的一些实施方式，优选地，所述单晶型多元正极材料的粒度D 10为1.5-2.5μm。
根据本发明的一些实施方式，优选地，所述单晶型多元正极材料的粒度D 50为3-5μm。
根据本发明的一些实施方式，优选地，所述单晶型多元正极材料的粒度D 90为6-8μm。
本发明中，所述粒度测试采用Marvern公司的Hydro 2000mu型号的激光粒度仪进行。
根据本发明的一些实施方式，K 90的值越小，则单晶颗粒的均一性越好；K 90的值越大，则单晶颗粒的均一性越差。优选地，K 90为1.18-1.25，优选为1.20-1.22。采用上述优选实施方式的单晶型多元正极材料，其单晶颗粒的均一性更好，有利于增大级配，提升材料的压实密度。
根据本发明的一些实施方式，优选地，所述单晶型多元正极材料具有式I所示的结构：
Li 1+a(Ni xCo yMn zG b)M cO 2-d    式I；
式中，-0.05≤a≤0.3，0≤b≤0.05，0≤c≤0.05，0.5≤x＜1，0＜y＜0.5，0＜z＜0.5；d的取值确保正负电荷数相等；G为Ti、W、V、Ta、Zr、La、Ce、Er、Sr、Si、Al、B、Mg、Co、F和Y中的一种或几种；M为Sr、F、B、Al、Nb、Co、Mn、Mo、W、Si、Mg、Ti和Zr中的一种或几种；
更优选地，式中，0≤a≤0.2，0.0001≤b≤0.005，0.0001≤c≤0.005，0.5≤x≤0.95，0.01≤y≤0.4，0.01≤z≤0.4。
更优选地，式中，G为Ti、W、Zr、Sr、Si、Al、B和F中的一种或几种；和/或，M为Sr、F、B、Al、W、Si和Ti中的一种或几种。
采用上述优选实施方式，有利于进一步提高电池的能量密度、倍率性能和循环稳定性。
根据本发明的一些实施方式，式I中，若G和M均为阳离子，则d＝0；若G和M均为阴离子，则d＝b+c；若G为阴离子，M为阳离子，则d＝b；若M为阴离子，G为阳离子，则 d＝c。
根据本发明的一些实施方式，优选地，定义所述单晶型多元正极材料的团聚率为B，由SEM测得的任意300个该单晶型多元正极材料的单晶颗粒中，具有团聚形态的单晶颗粒的个数为n，其中，B＝n/300*100％，且B为0-3.0％，优选为0.8-2.4％。团聚率B越大则表明正极材料的单晶化程度越低，反之则单晶化程度越高。电池在高电压下或者长循环过程中，粘连在一起的正极材料颗粒容易脱落或是碎裂，从而导致电池组的失效。一般而言，团聚率B的值越小，则循环性能越优。采用上述优选实施方式的单晶型多元正极材料，其单晶颗粒的团聚率小，单晶化程度高，粘连少，在高电压下或者长循环过程中不易脱落或碎裂，有利于进一步提升电池的能量密度、倍率性能和循环稳定性。
根据本发明的一些实施方式，优选地，定义所述单晶型多元正极材料由SEM测得的任意300个单晶颗粒的最长对角线的长度与最短对角线的长度的平均值为晶粒尺寸P 50，且P 50为1.5-3.0μm，优选为2.0-2.4μm。P 50的值过大，则会增加锂离子在正极材料内部的传输距离，影响容量的发挥；P 50的值过小，则会导致材料团聚，甚至无法形成单晶材料，影响材料的循环性能。采用上述优选实施方式的单晶型多元正极材料，有利于进一步提高所述单晶型多元正极材料的容量和循环性能。
本发明中，所述单晶型多元正极材料在制备过程中采用二次烧结工艺，其第一烧结过程中，升温段采用氧气气氛，恒温段采用空气气氛，使得单晶颗粒形貌更圆润规整、尺寸更均一、团聚粘连更少，压实密度更高，有利于提高电池的能量密度、倍率性能和循环稳定性。
本发明第二方面提供一种单晶型多元正极材料的制备方法，所述制备方法包括：
(1)将含有镍钴锰前驱体和锂源的混合物进行第一烧结，并将得到的产物进行破碎处理，得到单晶型正极材料过程品；
(2)将所述单晶型正极材料过程品进行第二烧结，得到单晶型多元正极材料；
其中，所述第一烧结包括依次进行的升温阶段I和恒温阶段I，所述升温阶段I在氧气气氛下进行，所述恒温阶段I在空气气氛下进行；
所述第二烧结的温度不高于所述第一烧结的温度。
现有的制备单晶正极材料的方法大多采用单一气氛(空气或氧气)进行烧结，使得单晶颗粒棱角明显、圆润度及规整度较差，或者单晶颗粒间粘连严重、独立性差，甚至仍保持类前驱体形貌。而本发明的发明人在研究过程中发现，镍钴锰前驱体与锂源的混合物固相反应分为生长和融合两个阶段，生长阶段为温度较低的升温段，即锂源熔融渗透入前驱体颗粒内部，并 发生初步反应，让构成前驱体的纤维长大变饱满，长成为细小的一次颗粒；融合阶段为温度较高的恒温段，即锂源与细小的一次颗粒进一步反应，使其融合成大个颗粒的过程。通过在镍钴锰前驱体与锂源反应的升温成核阶段(第一烧结的升温阶段I)采用氧气气氛，让纤维形成的一次颗粒更加饱满圆润，在恒温烧结的增长阶段(第一烧结的恒温阶段I)采用空气气氛，使单晶颗粒间更容易地融合形成大的单晶颗粒，进一步通过二次烧结(第二烧结)使得正极材料成品颗粒更为圆润规整，得到的单晶型多元正极材料的形貌圆润规整、颗粒尺寸均一，并且团聚少、粘连少，具有压实密度高，倍率性能好和循环性能优异的特点。
根据本发明的一些实施方式，步骤(1)中，所述镍钴锰前驱体可以为本领域所公知的适用于制备正极材料的镍钴锰前驱体，对此没有特别的限制，其均能在一定程度上实现本发明的发明目的。优选地，所述镍钴锰前驱体选自含有镍、钴和锰的氧化物和/或氢氧化物。
根据本发明的一些实施方式，步骤(1)中，所述锂源可以为本领域所公知的适用于制备正极材料的锂源，对此没有特别的限制，其均能在一定程度上实现本发明的发明目的。优选地，所述锂源选自碳酸锂和/或氢氧化锂。
根据本发明的一些实施方式，优选地，步骤(1)中，按照化学计量比计，所述锂源的用量满足：1.02≤[n(Li)]/[n(Ni)+n(Co)+n(Mn)]≤1.06。
根据本发明的一些实施方式，优选地，步骤(1)中，所述混合的原料还包括添加剂，所述添加剂选自含有G的化合物，优选为含有G的氧化物、氢氧化物、碳酸盐和氟化物中的至少一种，更优选为氧化锆、碳酸锶、氢氧化锶、二氧化硅、氧化铝、氢氧化铝、三氧化钨、氧化钛、氟化铝和氧化硼中的至少一种。其中，G可以参照上文进行选用，在此不再赘述。本发明中，所述添加剂有利于材料单晶化的形成，降低内阻、提高材料的循环稳定性。
根据本发明的一些实施方式，优选地，步骤(1)中，按照化学计量比计，以G元素计的所述添加剂的用量满足：0.0001≤[n(G)]/[n(Ni)+n(Co)+n(Mn)]≤0.005。
根据本发明的一些实施方式，步骤(1)中，所述升温阶段I在氧气气氛下进行，通过在镍钴锰前驱体与锂源反应的升温成核阶段(即第一烧结的升温阶段I)采用氧气气氛，能够使得纤维形成的一次颗粒更加饱满圆润。
根据本发明的一些实施方式，优选地，步骤(1)中，所述升温阶段I的条件还包括：升温时间为2-10h，优选为6-8h。所述升温阶段I中，通过上述升温时间升温至恒温阶段I的恒温温度。
根据本发明的一些实施方式，步骤(1)中，所述恒温阶段I在空气气氛下进行，通过在 恒温烧结的增长阶段(第一烧结的恒温阶段I)采用空气气氛，能够使单晶颗粒间更容易地融合形成大的单晶颗粒。
根据本发明的一些实施方式，优选地，步骤(1)中，所述恒温阶段I的条件还包括：恒温温度为600-1100℃，优选为900-1000℃；恒温时间为6-12h，优选为8-10h。
根据本发明的一些实施方式，优选地，步骤(1)中，所述镍钴锰前驱体的粒度中值D 50为3-5μm。
根据本发明的一些实施方式，优选地，步骤(1)中，所述单晶型正极材料过程品的粒度中值D′ 50为3-5μm。
根据本发明的一些实施方式，优选地，步骤(1)中，所述镍钴锰前驱体的粒度中值D 50与所述单晶型正极材料过程品的粒度中值D′ 50满足式II：
|(D 50-D′ 50)/D 50|＜5％    式II。
采用上述优选实施方式有利于获得单晶颗粒的粒度D 10、D 50、D 90以及均一性K 90满足上述要求的单晶型多元正极材料。
根据本发明的一些实施方式，步骤(1)中，通过所述第一烧结结合所述破碎处理，使得到的单晶型正极材料过程品的粒度中值D′ 50满足上述要求。对所述破碎处理所采用的设备没有特别的限制，只要能够获得粒度中值D′ 50满足上述要求的单晶型正极材料过程品即可，优选地，所述破碎处理采用的设备选自豆浆机、鄂破、对辊、胶体磨、机械磨和气流磨中的至少一种。
根据本发明的一些实施方式，优选地，步骤(2)中，先将所述单晶型正极材料过程品与包覆剂进行混合，再将得到的混合物进行所述第二烧结；所述包覆剂选自含有M的化合物，优选为含有M的氧化物、氢氧化物、碳酸盐和氟化物中的至少一种，更优选为碳酸锶、氢氧化锶、二氧化硅、氧化铝、氢氧化铝、三氧化钨、氧化钛、氟化铝和氧化硼中的至少一种。其中，M可以参照上文进行选用，在此不再赘述。本发明中，所述包覆剂有利于降低游离锂，提高材料在高温、高电压环境下的循环稳定性。
根据本发明的一些实施方式，优选地，步骤(2)中，按照化学计量比计，以M元素计的所述包覆剂的用量满足：0.0001≤[n(M)]/[n(Ni)+n(Co)+n(Mn)]≤0.005。
根据本发明的一些实施方式，所述镍钴锰前驱体、所述锂源、所述添加剂和所述包覆剂的用量使得得到的单晶型多元正极材料中，n(Li)：n(Ni)：n(Co)：n(Mn)：n(G)：n(M)＝(1+a)：x：y：z：b：c，其中，a、b、c、x、y、z的取值可参照上文进行定义和选用，在此不再赘述。
根据本发明的一些实施方式，优选地，步骤(2)中，所述第二烧结在空气气氛下进行。
根据本发明的一些实施方式，优选地，步骤(2)中，所述第二烧结包括依次进行的升温阶段II和恒温阶段II。
根据本发明的一些实施方式，优选地，步骤(2)中，所述升温阶段II的条件还包括：升温时间为2-10h，优选为4-7h。
根据本发明的一些实施方式，优选地，步骤(2)中，所述恒温阶段II的条件还包括：恒温温度为500-900℃，优选为600-800℃；恒温时间为6-12h，优选为8-10h。
根据本发明的一些实施方式，优选地，定义ΔP为单晶型多元正极材料的晶粒尺寸变化值，单位为μm；ΔT为同一烧结步骤下的温度变化值，单位为℃；Δt为同一烧结步骤下的时间变化值，单位为h，且三者满足：ΔP＝ωΔT+γΔt，其中，ω＝0.02μm/℃，γ＝0.1μm/h。例如，当第一烧结的恒温阶段I的恒温温度为T 1℃，恒温时间为t 1h时，得到的单晶型多元正极材料的晶粒尺寸P 50为P 1μm；当第一烧结的恒温阶段I的恒温温度为T 2℃，恒温时间为t 2h时，得到的单晶型多元正极材料的晶粒尺寸P 50为P 2μm，则ΔT为T 1与T 2之差的绝对值(即|T 1-T 2|℃)，Δt为t 1与t 2之差的绝对值(即|t 1-t 2|h)，ΔP为P 1与P 2之差的绝对值(即|P 1-P 2|μm)，且ΔP＝ωΔT+γΔt。
本发明第三方面提供一种由第二方面所述的制备方法制备得到的单晶型多元正极材料。
根据本发明的一些实施方式，所述单晶型多元正极材料与本发明第一方面所述的单晶型多元正极材料相同或相似，在此不再赘述。
本发明第四方面提供一种锂离子电池，所述锂离子电池含有第一方面或第三方面所述的单晶型多元正极材料。
以下将通过实施例对本发明进行详细描述。
以下实施例和对比例中，若没有特别说明，所使用的原料均为市售品。
以下实施例和对比例中，相关参数通过以下方法测试得到：
(1)形貌测试：通过日本日立HITACHI公司S-4800型号的扫描电子显微镜测试得到，其中，圆润度R、团聚率B和晶粒尺寸P 50均通过SEM图测试得到；
(2)粒度D 10、D 50、D 90：通过Marvern公司的Hydro 2000mu型号的激光粒度仪测试得到；
(3)压实密度：通过百特公司BT-30型号的振实密度测试仪测试得到；
(4)电化学性能测试：
以下实施例和对比例中，单晶型多元正极材料的电化学性能采用CR2032扣式电池进行测试。
CR2032扣式电池的制备过程具体如下：
极片制备：将单晶型多元正极材料、导电碳黑和聚偏二氟乙烯(PVDF)按照95：2：3的质量比与适量的N-甲基吡咯烷酮(NMP)充分混合，形成均匀的浆料，将该浆料涂覆在铝箔上于120℃干燥12h后，使用100MPa的压力将其冲压成型，制成直径为15.8mm、厚度为3.2mm的正极极片，其中，单晶型多元正极材料的负载量为15.5mg/cm 2。
电池组装：在水含量与氧含量均小于5ppm的充有氩气的气手套箱内，将正极极片、隔膜、负极极片以及电解液组装成CR2032扣式电池后，静置6h。其中，负极极片使用直径为15.8mm、厚度为1mm的金属锂片；隔膜使用厚度为25μm的聚丙烯微孔膜(Celgard 2325)；电解液使用1mol/L的LiPF 6、碳酸乙烯酯(EC)和碳酸二乙酯(DEC)的等量混合液。
电化学性能测试：
以下实施例和对比例中，采用深圳新威尔电池测试系统对CR2032扣式电池进行电化学性能测试，0.1C的充放电电流密度为100mA/g。
控制充放电电压区间为3.0-4.4V，在室温下，将扣式电池分别在0.1C和0.3C下进行充放电测试，评估单晶型多元正极材料的充放电比容量。
高温循环性能测试：控制充放电电压区间为3.0-4.4V，在恒温60℃下，将扣式电池在0.1C下充放电循环2次，然后在1C下充放电循环80次，评估单晶型多元正极材料的高温循环容量保持率。
倍率性能测试：控制充放电电压区间为3.0-4.4V，在室温下，将扣式电池在0.1C下充放电循环2次，然后在0.3C下充放电循环1次，以0.1C首次放电比容量与0.3C放电比容量的比值评估多元正极材料的倍率性能。
实施例1
(1)将含有镍钴锰前驱体、锂源和添加剂的混合物进行第一烧结，并将得到的产物进行破碎处理，得到单晶型正极材料过程品；其中：
镍钴锰前驱体为含有镍、钴和锰的氢氧化物，其化学式见表2；锂源和添加剂的种类以及各原料的用量见表1；破碎处理采用的设备为豆浆机；
第一烧结为依次进行的升温阶段I和恒温阶段I，具体条件见表1；
镍钴锰前驱体的粒度中值D 50和单晶型正极材料过程品的粒度中值D′ 50见表1；
(2)将该单晶型正极材料过程品进行第二烧结，得到单晶型多元正极材料；其中：
第二烧结在空气气氛下进行；第二烧结为依次进行的升温阶段II和恒温阶段II，具体条件见表1；反应过程中，各产物的化学式见表2。
实施例2
按照实施例1的方法，不同的是，步骤(1)中，第一烧结的恒温阶段I的恒温温度以及单晶型正极材料过程品的粒度中值D′ 50，具体见表1，其余均相同，得到单晶型多元正极材料。
实施例3
按照实施例1的方法，不同的是，步骤(1)中，第一烧结的恒温阶段I的恒温温度以及单晶型正极材料过程品的粒度中值D′ 50，具体见表1，其余均相同，得到单晶型多元正极材料。
其余的实施例均按照实施例1的方法，不同之处见表1，其余均相同，分别得到单晶型多元正极材料。
对比例1
按照实施例1的方法，不同的是，步骤(1)中，第一烧结均在空气气氛下进行，其余均相同，得到单晶型多元正极材料。
对比例2
按照实施例1的方法，不同的是，步骤(1)中，第一烧结均在氧气气氛下进行，其余均相同，得到单晶型多元正极材料。
对比例3
按照实施例2的方法，不同的是，步骤(1)中，第一烧结均在空气气氛下进行，其余均相同，得到单晶型多元正极材料。
对比例4
按照实施例3的方法，不同的是，步骤(1)中，第一烧结均在氧气气氛下进行，其余均相同，得到单晶型多元正极材料。
对比例5
按照实施例3的方法，不同的是，步骤(1)中，得到的单晶型正极材料过程品的D′ 50为3.64μm，|(D 50-D′ 50)/D 50|＝13.3％，其余均相同，得到单晶型多元正极材料，其均一性K 90见表3。
对比例6
按照实施例3的方法，不同的是，步骤(1)中，得到的单晶型正极材料过程品的D′ 50为4.49μm，|(D 50-D′ 50)/D 50|＝6.9％，其余均相同，得到单晶型多元正极材料，其均一性K 90见表3。
表1
Figure PCTCN2022144086-appb-000001
Figure PCTCN2022144086-appb-000002
注：用量 1即为镍钴锰前驱体中镍钴锰元素的总摩尔量：锂源中锂元素的摩尔量：添加剂中G元素的摩尔量；
用量 2即为镍钴锰前驱体中镍钴锰元素的总摩尔量：包覆剂中M元素的摩尔量。
表2
Figure PCTCN2022144086-appb-000003
Figure PCTCN2022144086-appb-000004
测试例1
分别将实施例和对比例得到的单晶型多元正极材料进行测试，包括团聚率B、粒度D 10、粒度D 50、粒度D 90、均一性K 90和圆润度R，结果见表3。
表3
编号 团聚率B D 10 D 50 D 90 K 90 圆润度R K 90*R
单位 ％ μm μm μm / / /
实施例1 1.30 2.11 4.22 7.24 1.22 1.05 1.28
实施例2 2.40 2.01 4.16 7.03 1.21 1.09 1.32
实施例3 0.80 2.37 4.34 7.58 1.20 1.14 1.37
实施例4 1.20 2.04 3.90 6.78 1.22 1.03 1.25
实施例5 1.30 1.93 3.60 6.41 1.24 1.06 1.32
对比例1 1.40 2.31 4.32 7.83 1.28 1.47 1.88
对比例2 4.30 1.93 4.09 6.73 1.14 1.21 1.42
对比例3 2.10 2.01 4.22 7.38 1.27 1.54 1.96
对比例4 1.80 1.99 4.13 7.37 1.30 1.26 1.64
对比例5 1.60 1.43 3.74 7.97 1.75 1.06 1.85
对比例6 1.70 2.22 4.55 6.78 1.00 1.09 1.09
测试例2
分别将实施例和对比例得到的单晶型多元正极材料进行测试，包括晶粒尺寸P 50和压实密度，以及电化学性能测试，结果见表4。
表4
编号 晶粒尺寸P 50 压实密度 首次放电比容量 放电比容量 0.3C/0.1C 容量保持率 3
单位 μm g/cm 3 0.1C mAh/g 0.3C mAh/g ％ ％
实施例1 2.2 3.27 190.4 183.4 96.3 95.2
实施例2 1.8 3.12 191.3 183.2 95.8 94.6
实施例3 2.6 3.18 189.9 182.9 96.3 95.2
实施例4 2.2 3.24 206.5 196.8 95.3 93.5
实施例5 2.2 3.21 212.7 201.4 94.7 93.2
对比例1 2.6 2.77 186.4 173.2 92.9 89.3
对比例2 1.8 2.63 185.9 174.1 93.7 88.4
对比例3 2.2 2.83 186.1 172.2 92.5 88.5
对比例4 2.2 2.87 186.0 173.8 93.4 88.6
对比例5 2.2 2.99 188.1 177.6 94.4 87.9
对比例6 2.2 2.97 187.4 176.3 94.1 88.1
注：容量保持率 3即为高温循环容量保持率。
本发明示例性地提供了实施例1-3和对比例1-4得到的单晶型多元正极材料的扫描电镜(SEM)图，分别依次如图1-7所示。从图中可知，与实施例2-3得到的单晶型多元正极材料(图2、3)和对比例1-2得到的单晶型多元正极材料(图4-5)相比，本发明实施例1得到的单晶型多元正极材料(图1)的单晶颗粒圆润规整，形貌更佳；
实施例2得到的单晶型多元正极材料(图2)和对比例2得到的单晶型多元正极材料(图5)的单晶颗粒的晶粒尺寸P 50为1.8μm，从电镜图中可以清楚地看到仍有部分颗粒保持前驱体形貌，且颗粒间存在粘连，但与对比例2得到的单晶型多元正极材料相比，本发明实施例2在一次烧结的过程中，通过氧气加空气的烧结工艺而得的单晶型多元正极材料，其颗粒独立性以及规整度更优；
实施例3得到的单晶型多元正极材料(图3)和对比例1得到的单晶型多元正极材料(图 4)的单晶颗粒的晶粒尺寸P 50为2.6μm，晶体颗粒较大，独立性好但规整度差，但与对比例1得到的单晶型多元正极材料相比，本发明实施例3得到的单晶型多元正极材料的单晶颗粒更为圆润；
实施例1得到的单晶型多元正极材料以及对比例3、4得到的单晶型多元正极材料的单晶颗粒的晶粒尺寸P 50均为2.2μm，但与对比例3、4得到的单晶型多元正极材料相比，本发明实施例1得到的单晶型多元正极材料的单晶颗粒，其圆润度及独立程度均更优。
通过上述结果可以看出，本发明提供的单晶型多元正极材料的形貌更为圆润规整，且其单晶颗粒的尺寸均一、团聚少、粘连少，具有压实密度高，倍率性能好，循环性能优异的特点。其中：
比较实施例1-3和对比例1、2可以看出，当单晶颗粒的晶粒尺寸P 50为2.0-2.4μm时，综合性能最优，压实密度最高，倍率及高温循环保持率最优，容量能够保持在较高水平；当P 50＜2.0μm时，压实密度会随之降低，倍率及保持率变差，但是由于晶体颗粒变小后，锂离子在颗粒内部传输的路径变短，容量略有提升；当P 50＞2.4μm时，压实密度也会降低，降低趋势较P 50＜2.0μm时要小；
比较实施例2和对比例2，以及实施例3和对比例1可以看出，在一次烧结全程为空气气氛的条件下，锂源熔融后再颗粒表面，晶体的生长方向是从外部开始生长，因此需要较低的温度即可涨大；而在一次烧结全程为氧气气氛的条件下晶体较多，且是从颗粒内部开始生长，需要更高的温度才得以涨大。对比单晶型多元正极材料的压实密度以及电化学性能可以看出，通过本发明提供的一次烧结升温段氧气加恒温段空气的烧结方式得到的单晶型多元正极材料的单晶颗粒具有更优的压实密度，以及更优的电化学性能；
比较实施例1与对比例3、4可以看出，采用不同工艺制备得到的单晶型多元正极材料，即使其具有相同的晶粒尺寸，其性能也不相同，一次烧结采用升温段氧气加恒温段空气的烧结方式制备而得的单晶型多元正极材料，其压实密度及电化学性能明显优于采用单一气氛制备而得的多元正极材料；
此外，团聚率会影响到材料的循环性能，从上表可以看出，晶粒尺寸的大小与团聚率有直接关系，晶粒尺寸越大，团聚率越小，循环性能相对越好；同时烧结气氛也对团聚率和循环性能有一定影响，在晶粒尺寸相当的情况下，通过本发明一次烧结氧气结合空气的烧结方式，制备的单晶颗粒团聚率明显低于一次烧结在单一的氧气或空气气氛下进行而制得的颗粒(氧气气氛下的团聚率小于空气气氛下的团聚率)，对应的多元正极材料的循环性能：氧气结合空气 ＞氧气＞空气。同时，通过圆润度指标也可以看出，本发明提供的方法得到的单晶型多元正极材料的单晶颗粒更加圆润规则，且相同晶粒尺寸下，单一氧气气氛的圆润度优于单一空气气氛的圆润度；
由实施例4及实施例5可以看出，本发明提供的方法在高镍产品上同样适用。随着镍含量的增加，钴含量的降低，多元正极材料的圆润度以及压实密度均能保持在较高水平，电化学性能方面容量会明显提高，但倍率性能及循环性能会相应变差；
由实施例1与对比例5和6可以看出，相同的烧结方式制备的不同粒度分布的多元正极材料，在其圆润度满足本发明限定范围的条件下，K 90过大或过小，导致K 90与R的乘积超出本发明限定的范围，其压实密度、容量及循环寿命均会有不同程度的降低。以上详细描述了本发明的优选实施方式，但是，本发明并不限于此。在本发明的技术构思范围内，可以对本发明的技术方案进行多种简单变型，包括各个技术特征以任何其它的合适方式进行组合，这些简单变型和组合同样应当视为本发明所公开的内容，均属于本发明的保护范围。

Claims (13)

  1. 一种单晶型多元正极材料，其特征在于，定义所述单晶型多元正极材料的单晶颗粒由SEM测得的最长对角线的长度与最短对角线的长度的比值为圆润度R，且R≥1；
    所述单晶型多元正极材料的单晶颗粒的D 10、D 50和D 90满足：K 90＝(D 90-D 10)/D 50，K 90与R的乘积为1.20-1.40。
  2. 根据权利要求1所述的单晶型多元正极材料，其中，R为1-1.2；
    和/或，K 90与R的乘积为1.25-1.35；
    和/或，K 90为1.18-1.25，优选为1.20-1.22。
  3. 根据权利要求1所述的单晶型多元正极材料，其中，所述单晶型多元正极材料具有式I所示的结构：
    Li 1+a(Ni xCo yMn zG b)M cO 2-d式I；
    式中，-0.05≤a≤0.3，0≤b≤0.05，0≤c≤0.05，0.5≤x＜1，0＜y＜0.5，0＜z＜0.5；d的取值确保正负电荷数相等；G为Ti、W、V、Ta、Zr、La、Ce、Er、Sr、Si、Al、B、Mg、Co、F和Y中的一种或几种；M为Sr、F、B、Al、Nb、Co、Mn、Mo、W、Si、Mg、Ti和Zr中的一种或几种；
    优选地，式中，0≤a≤0.2，0.0001≤b≤0.005，0.0001≤c≤0.005，0.5≤x≤0.95，0.01≤y≤0.4，0.01≤z≤0.4；
    和/或，G为Ti、W、Zr、Sr、Si、Al、B和F中的一种或几种；
    和/或，M为Sr、F、B、Al、W、Si和Ti中的一种或几种。
  4. 根据权利要求1-3中任意一项所述的单晶型多元正极材料，其中，所述单晶型多元正极材料的团聚率为B，且B为0-3.0％，优选为0.8-2.4％。
  5. 根据权利要求1-3中任意一项所述的单晶型多元正极材料，其中，所述单晶型多元正极材料的单晶颗粒的最长对角线的长度与最短对角线的长度的平均值为晶粒尺寸P 50，且P 50为1.5-3.0μm，优选为2.0-2.4μm。
  6. 一种单晶型多元正极材料的制备方法，其特征在于，所述制备方法包括：
    (1)将含有镍钴锰前驱体和锂源的混合物进行第一烧结，并将得到的产物进行破碎处理，得到单晶型正极材料过程品；
    (2)将所述单晶型正极材料过程品进行第二烧结，得到单晶型多元正极材料；
    其中，所述第一烧结包括依次进行的升温阶段I和恒温阶段I，所述升温阶段I在氧气气氛下进行，所述恒温阶段I在空气气氛下进行；
    所述第二烧结的温度不高于所述第一烧结的温度。
  7. 根据权利要求6所述的制备方法，其中，步骤(1)中，所述镍钴锰前驱体选自含有镍、钴和锰的氧化物和/或氢氧化物；
    和/或，所述锂源选自碳酸锂和/或氢氧化锂；
    和/或，所述混合的原料还包括添加剂，所述添加剂选自含有G的化合物，优选为含有G的氧化物、氢氧化物、碳酸盐和氟化物中的至少一种，更优选为氧化锆、碳酸锶、氢氧化锶、二氧化硅、氧化铝、氢氧化铝、三氧化钨、氧化钛、氟化铝和氧化硼中的至少一种。
  8. 根据权利要求6或7所述的制备方法，其中，步骤(1)中，所述升温阶段I的条件还包括：升温时间为2-10h，优选为6-8h；
    和/或，所述恒温阶段I的条件还包括：恒温温度为600-1100℃，优选为900-1000℃；恒温时间为6-12h，优选为8-10h；
    和/或，所述镍钴锰前驱体的粒度中值D 50与所述单晶型正极材料过程品的粒度中值D′ 50满足式II：
    |(D 50-D′ 50)/D 50|＜5％  式II。
  9. 根据权利要求6-8中任意一项所述的制备方法，其中，步骤(2)中，先将所述单晶型正极材料过程品与包覆剂进行混合，再将得到的混合物进行所述第二烧结；所述包覆剂选自含有M的化合物，优选为含有M的氧化物、氢氧化物、碳酸盐和氟化物中的至少一种，更优选为碳酸锶、氢氧化锶、二氧化硅、氧化铝、氢氧化铝、三氧化钨、氧化钛、氟化铝和氧化硼中的至少一种。
  10. 根据权利要求6-8中任意一项所述的制备方法，其中，步骤(2)中，所述第二烧结在空气气氛下进行；
    和/或，所述第二烧结包括依次进行的升温阶段II和恒温阶段II；
    和/或，所述升温阶段II的条件还包括：升温时间为2-10h，优选为4-7h；
    和/或，所述恒温阶段II的条件还包括：恒温温度为500-900℃，优选为600-800℃；恒温时间为6-12h，优选为8-10h。
  11. 根据权利要求6-8中任意一项所述的制备方法，其中，定义ΔP为单晶型多元正极材料的晶粒尺寸变化值，单位为μm；ΔT为同一烧结步骤下的温度变化值，单位为℃；Δt为同一烧结步骤下的时间变化值，单位为h，且三者满足：ΔP＝ωΔT+γΔt，其中，ω＝0.02μm/℃，γ＝0.1μm/h。
  12. 一种由权利要求6-11中任意一项所述的制备方法制备得到的单晶型多元正极材料。
  13. 一种锂离子电池，其特征在于，所述锂离子电池含有权利要求1-5或12中任意一项所述的单晶型多元正极材料。
PCT/CN2022/144086 2022-12-22 2022-12-30 单晶型多元正极材料及其制备方法和锂离子电池 WO2023169064A1 (zh)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP22930683.2A EP4306687A1 (en) 2022-12-22 2022-12-30 Single crystal multi-element positive electrode material, preparation method therefor, and lithium ion battery
JP2023560160A JP2024511223A (ja) 2022-12-22 2022-12-30 単結晶型多元正極材料、その製造方法、及びリチウムイオン電池
US18/497,404 US11955635B1 (en) 2022-12-22 2023-10-30 Single crystal multi-element positive electrode material, preparation method therefor, and lithium ion battery

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211659558.1A CN116169261A (zh) 2022-12-22 2022-12-22 单晶型多元正极材料及其制备方法和锂离子电池
CN202211659558.1 2022-12-22

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US18/497,404 Continuation US11955635B1 (en) 2022-12-22 2023-10-30 Single crystal multi-element positive electrode material, preparation method therefor, and lithium ion battery

Publications (1)

Publication Number Publication Date
WO2023169064A1 true WO2023169064A1 (zh) 2023-09-14

Family

ID=86419202

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2022/144086 WO2023169064A1 (zh) 2022-12-22 2022-12-30 单晶型多元正极材料及其制备方法和锂离子电池

Country Status (5)

Country Link
US (1) US11955635B1 (zh)
EP (1) EP4306687A1 (zh)
JP (1) JP2024511223A (zh)
CN (1) CN116169261A (zh)
WO (1) WO2023169064A1 (zh)

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108923041A (zh) * 2018-05-29 2018-11-30 深圳市德方纳米科技股份有限公司 三元正极材料及其制备方法和锂离子电池
CN110697787A (zh) * 2019-09-11 2020-01-17 中国科学院化学研究所 一种锂离子电池用高体积能量密度三元正极材料及制备方法
CN112301428A (zh) * 2020-09-24 2021-02-02 广东邦普循环科技有限公司 一种三元单晶正极材料及其制备方法和应用
US20210126242A1 (en) * 2018-12-29 2021-04-29 Contemporary Amperex Technology Co., Limited High-compacted-density positive electrode material and electrochemical energy storage apparatus
US20210143423A1 (en) * 2018-03-29 2021-05-13 Umicore Methods for preparing positive electrode material for rechargeable lithium ion batteries
CN113036095A (zh) * 2020-03-27 2021-06-25 湖南杉杉能源科技股份有限公司 一种单晶形貌锂离子电池正极材料的制备方法
CN113620352A (zh) * 2021-07-06 2021-11-09 江门市科恒实业股份有限公司 一种高电压单晶三元正极材料及其制备方法
CN114703544A (zh) * 2021-12-24 2022-07-05 北京当升材料科技股份有限公司 单晶型多元正极材料及其制备方法与应用
CN114843502A (zh) * 2022-05-16 2022-08-02 北京卫蓝新能源科技有限公司 一种高倍率单晶高镍正极材料及其制备方法和应用
US20220285676A1 (en) * 2019-08-30 2022-09-08 Sumitomo Metal Mining Co., Ltd. Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery
CN115084506A (zh) * 2022-05-18 2022-09-20 广东邦普循环科技有限公司 大粒径单晶三元正极材料及其制备方法和应用
CN115332530A (zh) * 2021-05-10 2022-11-11 比亚迪股份有限公司 磷酸铁锂正极材料及其制备方法和锂离子电池

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2023182443A (ja) * 2022-06-14 2023-12-26 トヨタ自動車株式会社 正極活物質粒子、ナトリウムイオン二次電池、及び、正極活物質粒子の製造方法

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20210143423A1 (en) * 2018-03-29 2021-05-13 Umicore Methods for preparing positive electrode material for rechargeable lithium ion batteries
CN108923041A (zh) * 2018-05-29 2018-11-30 深圳市德方纳米科技股份有限公司 三元正极材料及其制备方法和锂离子电池
US20210126242A1 (en) * 2018-12-29 2021-04-29 Contemporary Amperex Technology Co., Limited High-compacted-density positive electrode material and electrochemical energy storage apparatus
US20220285676A1 (en) * 2019-08-30 2022-09-08 Sumitomo Metal Mining Co., Ltd. Positive electrode active material for lithium ion secondary battery and lithium ion secondary battery
CN110697787A (zh) * 2019-09-11 2020-01-17 中国科学院化学研究所 一种锂离子电池用高体积能量密度三元正极材料及制备方法
CN113036095A (zh) * 2020-03-27 2021-06-25 湖南杉杉能源科技股份有限公司 一种单晶形貌锂离子电池正极材料的制备方法
CN112301428A (zh) * 2020-09-24 2021-02-02 广东邦普循环科技有限公司 一种三元单晶正极材料及其制备方法和应用
CN115332530A (zh) * 2021-05-10 2022-11-11 比亚迪股份有限公司 磷酸铁锂正极材料及其制备方法和锂离子电池
CN113620352A (zh) * 2021-07-06 2021-11-09 江门市科恒实业股份有限公司 一种高电压单晶三元正极材料及其制备方法
CN114703544A (zh) * 2021-12-24 2022-07-05 北京当升材料科技股份有限公司 单晶型多元正极材料及其制备方法与应用
CN114843502A (zh) * 2022-05-16 2022-08-02 北京卫蓝新能源科技有限公司 一种高倍率单晶高镍正极材料及其制备方法和应用
CN115084506A (zh) * 2022-05-18 2022-09-20 广东邦普循环科技有限公司 大粒径单晶三元正极材料及其制备方法和应用

Also Published As

Publication number Publication date
JP2024511223A (ja) 2024-03-12
EP4306687A1 (en) 2024-01-17
CN116169261A (zh) 2023-05-26
US11955635B1 (en) 2024-04-09

Similar Documents

Publication Publication Date Title
US10553870B2 (en) Nickel manganese containing composite hydroxide and manufacturing method for producing same
US11482703B2 (en) Positive-electrode active material precursor for nonaqueous electrolyte secondary battery and method for manufacturing positive-electrode active material precursor for nonaqueous electrolyte secondary battery
CN110534733A (zh) 一种大单晶锂离子电池镍钴锰酸锂正极材料制备方法
CN109516509B (zh) 一种高压实单晶三元正极材料及其制备方法、应用
CN112582599B (zh) 一种无钴高镍四元正极材料、其制备方法及其应用
WO2018090956A1 (zh) 高电压锂电池正极材料、电池及制法和应用
KR20180130579A (ko) 나노-결정을 포함하는 다결정질 레이어드 금속 옥사이드
WO2022207008A1 (zh) 单晶型多元正极材料及其制备方法与应用
CN109461893B (zh) 一种新型锂离子电池正极材料及其制备方法
US20220340446A1 (en) Cobalt-free lamellar cathode material and method for preparing cobalt-free lamellar cathode material, cathode piece and lithium ion battery
US11949102B2 (en) Positive electrode active material precursor for nonaqueous electrolyte secondary battery and method for manufacturing positive electrode active material precursor for nonaqueous electrolyte secondary battery
WO2023193826A1 (zh) 正极材料及其制备方法与应用
CN114436347B (zh) 一种高镍三元正极材料及其制备方法和应用
CN113584590B (zh) 一种单晶三元正极材料及其制备方法
WO2023221625A1 (zh) 大粒径单晶三元正极材料及其制备方法和应用
CN109888225A (zh) 正极材料及其制备方法和锂离子电池
CN115995531A (zh) 一种正极活性材料、正极极片、锂离子电池及其应用
CN113422039A (zh) 三元系复合氧化物基体材料、三元正极材料及制备方法与由其制备的锂离子电池
WO2023169064A1 (zh) 单晶型多元正极材料及其制备方法和锂离子电池
CN116864687A (zh) 正极材料及其制备方法、锂离子电池
CN116282225A (zh) 表面一次颗粒非径向生长的前驱体及其制备方法、锂离子电池及其正极材料和涉电设备
CN112125351A (zh) 一种三元前驱体及其制备方法、三元材料及其制备方法、锂离子电池
CN115893524B (zh) 二次电池正极材料及其制备方法和应用
CN117430174B (zh) 氧化物前驱体及其制备方法和应用
US20230187626A1 (en) Cathode Material for a Lithium Ion Battery and Preparation Method and Application Thereof

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 2023560160

Country of ref document: JP

WWE Wipo information: entry into national phase

Ref document number: 2022930683

Country of ref document: EP

ENP Entry into the national phase

Ref document number: 2022930683

Country of ref document: EP

Effective date: 20231012

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

Ref document number: 22930683

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 1020237040229

Country of ref document: KR