WO2021238051A1 - 无钴正极材料、其制备方法及锂离子电池 - Google Patents

无钴正极材料、其制备方法及锂离子电池 Download PDF

Info

Publication number
WO2021238051A1
WO2021238051A1 PCT/CN2020/124466 CN2020124466W WO2021238051A1 WO 2021238051 A1 WO2021238051 A1 WO 2021238051A1 CN 2020124466 W CN2020124466 W CN 2020124466W WO 2021238051 A1 WO2021238051 A1 WO 2021238051A1
Authority
WO
WIPO (PCT)
Prior art keywords
cobalt
free
lithium
preparation
sintering
Prior art date
Application number
PCT/CN2020/124466
Other languages
English (en)
French (fr)
Inventor
江卫军
杨红新
乔齐齐
孙明珠
许鑫培
施泽涛
陈思贤
马加力
王鹏飞
Original Assignee
蜂巢能源科技有限公司
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 蜂巢能源科技有限公司 filed Critical 蜂巢能源科技有限公司
Priority to JP2022514560A priority Critical patent/JP7369277B2/ja
Priority to EP20937309.1A priority patent/EP3975292A4/en
Priority to US17/763,664 priority patent/US20240055577A1/en
Priority to KR1020227005073A priority patent/KR20220035191A/ko
Publication of WO2021238051A1 publication Critical patent/WO2021238051A1/zh

Links

Images

Classifications

    • 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
    • H01M4/04—Processes of manufacture in general
    • H01M4/0471—Processes of manufacture in general involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis
    • 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
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/90—Carbides
    • C01B32/914—Carbides of single elements
    • C01B32/991—Boron carbide
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/006—Compounds containing, besides nickel, two or more other elements, with the exception of oxygen or hydrogen
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
    • C—CHEMISTRY; METALLURGY
    • 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
    • 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
    • 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
    • C30B33/00—After-treatment of single crystals or homogeneous polycrystalline material with defined structure
    • 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
    • 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
    • H01M4/624—Electric conductive fillers
    • 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
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00—Crystal-structural characteristics
    • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
    • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/01—Particle morphology depicted by an image
    • C01P2004/03—Particle morphology depicted by an image obtained by SEM
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/60—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
    • 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

Definitions

  • the present invention relates to the field of lithium ion batteries, in particular to a cobalt-free positive electrode material, a preparation method thereof, and a lithium ion battery.
  • Cobalt-free cathode materials are more concerned in the field of lithium-ion batteries.
  • nickel-manganese layered materials have become a research hotspot in recent years due to their advantages of high energy density, low cost, and good cycle performance.
  • the study found that the nickel-manganese layered structure with higher nickel content (more than 80% by mole) has structural instability, poor safety, poor cycle performance, high alkalinity, and more side reactions with the electrolyte. Gas and other issues have caused the practical application of nickel-manganese layered materials to be limited.
  • the nickel-manganese cathode material does not contain cobalt element, and the content of nickel element is low, and the content of manganese element is high, the conductivity of the material is poor and the capacity is relatively low.
  • the use of Ti-doped LiNi 0.5 Mn 0.5-x Ti x O 2 can improve the conductivity of the cathode material to a certain extent, increasing the capacitance from 150mAh/g to 180mAh/g, but this capacitance It is still far lower than the current 200-210mAh/g of high nickel cathode materials.
  • Another existing document also provides an improved method for LiNi 0.5 Mn 0.5 O 2 material, which includes doping with silicon, the capacitance of the cathode material can be increased to 192mAh/g, but the cycle performance is still not ideal.
  • the maximum weekly circulation retention rate is only 78%.
  • the main purpose of the present invention is to provide a cobalt-free positive electrode material, a preparation method thereof, and a lithium ion battery, so as to solve the problem of high electric capacity but poor cycle performance of the existing lithium ion battery positive electrode material.
  • one aspect of the present invention provides a method for preparing a cobalt-free cathode material.
  • the preparation method includes: subjecting a lithium source material and a cobalt-free precursor to a first sintering process to obtain a sintered product; and crushing the sintered product to 1 to 2 ⁇ m to obtain a cobalt-free single crystal material; and subject the cobalt-free single crystal material, the boron coating agent and the carbon coating agent to a second sintering process to obtain a cobalt-free cathode material.
  • the first sintering process includes: subjecting the lithium source material and the cobalt-free precursor to a first mixing process to obtain a first mixture; sintering the first mixture in the presence of an air or oxygen atmosphere to obtain a sintered product; preferably Specifically, the first mixing process is carried out at a stirring speed of 2000-3000 rpm, and the mixing time is 5-20 min.
  • the temperature of the first sintering process is 700-1200°C, and the sintering time is 5-15h; preferably, the temperature of the first sintering process is 900-1000°C.
  • the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor is (0.95-1.10):1.
  • the lithium source material is one or more of the group consisting of lithium hydroxide, lithium carbonate, lithium acetate, lithium oxide, lithium nitrate and lithium oxalate;
  • the cobalt-free precursor is Ni 1-x Mn x (OH) 2 and 0.45 ⁇ x ⁇ 0.55;
  • the boron coating agent is selected from one or more of the group consisting of boric acid, boron oxide, boron nitrate and metaboric acid, and the carbon coating agent is selected from sucrose, glucose, One or more of the group consisting of PEG and TiC.
  • the second sintering process includes: subjecting the cobalt-free single crystal material with the boron coating agent and the carbon coating agent to a second mixing process to obtain a second mixture; sintering the second mixture to obtain a cobalt-free cathode material;
  • the preparation method further includes: sieving the product obtained in the second sintering process to remove particles with a particle size ⁇ 0.2 ⁇ m and particles with a particle size ⁇ 6 ⁇ m to obtain a cobalt-free cathode material; preferably, the second mixing treatment process It is carried out at a stirring speed of 2000 to 3000 rpm, and the mixing time is 10 to 20 minutes.
  • the temperature of the second sintering treatment process is 300-900°C, and the treatment time is 10-20 min; preferably, the D50 of the cobalt-free precursor is 0.5-2 ⁇ m.
  • Another aspect of the application also provides a cobalt-free cathode material, which is prepared by the above-mentioned preparation method.
  • the coating amount of the C element is 0.1 to 3%, and the coating amount of the B element is 0.01 to 1%.
  • Another aspect of the present application also provides a lithium ion battery, including a positive electrode material, and the positive electrode material includes the aforementioned cobalt-free positive electrode material.
  • a layered cobalt-free cathode material LiNi 1-x Mn x O 2 (0.45 ⁇ x ⁇ 0.55) is prepared by sintering a lithium source material and a cobalt-free precursor, and then crushed to 1 ⁇ 2 ⁇ m, a layered cobalt-free single crystal material can be obtained.
  • the surface of the layered cobalt-free single crystal material can fully contact and react with the electrolyte, and form a stable positive solid electrolyte interface membrane (SEI) during the initial cycle.
  • SEI solid electrolyte interface membrane
  • the above-mentioned cobalt-free single crystal material can greatly reduce gas production during the application process and improve the cycle performance of the material.
  • its particle size is limited to 1 ⁇ 2 ⁇ m, which is lower than ordinary secondary particles (approximately 10 ⁇ m) and ordinary single crystal materials (approximately 3 ⁇ 4 ⁇ m) This is beneficial to greatly improve the current rate performance of lithium materials compared to cobalt-containing cathode materials.
  • sintering the cobalt-free single crystal material with a boron coating agent and a carbon coating agent can form a boron carbide coating layer on the surface of the cobalt-free single crystal material.
  • Boron carbide not only has good electrical conductivity, but also has high strength and chemical stability.
  • the cobalt-free cathode material prepared by the above method has the advantages of stable structure, high capacitance, excellent current rate performance and good cycle performance.
  • Figure 1 shows a 2000 times scanning electron microscope image of the product obtained by the crushing treatment in Example 1 of the present invention
  • FIG. 2 shows the XRD pattern of the cobalt-free cathode material prepared according to Example 1 of the present invention
  • FIG. 3 shows a scanning electron microscope image of a cobalt-free cathode material prepared according to Example 1 of the present invention at a high magnification of 30,000 times;
  • FIG. 5 shows the charge and discharge curve of the cobalt-free cathode material prepared according to Embodiment 1 of the present invention
  • Fig. 6 shows the cycle curve of the cobalt-free cathode material prepared according to Example 1 of the present invention at 45°C;
  • FIG. 7 shows a scanning electron microscope image of a cobalt-free cathode material without a coating layer at a high magnification of 20000 times.
  • the current lithium ion battery cathode material has the problem of high capacity but poor cycle performance.
  • the present application provides a method for preparing a cobalt-free cathode material.
  • the preparation method includes: subjecting a lithium source material and a cobalt-free precursor to a first sintering process to obtain a sintered product; ⁇ 2 ⁇ m to obtain a cobalt-free single crystal material; subject the cobalt-free single crystal material, a boron coating agent and a carbon coating agent to a second sintering process to obtain a cobalt-free positive electrode material.
  • the layered cobalt-free cathode material LiNi 1-x Mn x O 2 (0.45 ⁇ x ⁇ 0.55) is prepared by sintering the lithium source material and the cobalt-free precursor, and then the layered cathode material can be obtained by crushing it to 1 ⁇ 2 ⁇ m Of cobalt-free single crystal materials.
  • the surface of the layered cobalt-free single crystal material can fully contact and react with the electrolyte, and form a stable positive solid electrolyte interface membrane (SEI) during the initial cycle.
  • SEI solid electrolyte interface membrane
  • the above-mentioned cobalt-free single crystal material can greatly reduce gas production during the application process and improve the cycle performance of the material.
  • the cobalt-free cathode material itself has poorer conductivity and lower capacity.
  • Crystal material (approximately 3 to 4 ⁇ m), which is beneficial to greatly improve the current rate performance of the cobalt-free cathode material.
  • sintering the cobalt-free single crystal material with a boron coating agent and a carbon coating agent can form a boron carbide coating layer on the surface of the cobalt-free single crystal material.
  • Boron carbide not only has good electrical conductivity, but also has high strength and chemical stability.
  • the cobalt-free cathode material prepared by the above method has the advantages of stable structure, high capacitance, excellent current rate performance and good cycle performance.
  • the above-mentioned sintering process is an aerobic sintering process, which can be realized by using devices and processes commonly used in the art.
  • the aforementioned sintering process includes: subjecting the lithium source material and the cobalt-free precursor to a first mixing process to obtain a first mixture; in the presence of an air or oxygen atmosphere, sintering the first mixture to obtain Sintered product.
  • mixing the lithium source material and the cobalt-free precursor is beneficial to improve the uniformity of the mixing of the two raw materials and the degree of sintering, thereby helping to improve the stability of the layered cobalt-free cathode material.
  • the first mixing process is performed at a stirring speed of 2000-300 rpm, and the mixing time is 5-20 min.
  • the temperature of the first sintering process is 700 to 1200° C., and the sintering time is 5 to 15 hours.
  • the temperature and the sintering time of the first sintering treatment include but are not limited to the above range, and limiting it to the above range is beneficial to further improve the stability of the layered cobalt-free cathode material. More preferably, the temperature of the first sintering process is 900-1000°C.
  • the nickel-manganese lithium battery prepared by the above preparation method has the advantages of stable structure, high electric capacity, excellent current rate performance and good cycle performance.
  • the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor is (0.95-1.10):1. Limiting the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor within the above range is beneficial to further improve the energy density, capacitance and structural stability of the positive electrode material.
  • the lithium source material and the cobalt-free precursor can be selected from commonly used types in the art.
  • the lithium source material is one or more of the group consisting of lithium hydroxide, lithium carbonate, lithium acetate, lithium oxide, lithium nitrate, and lithium oxalate;
  • the cobalt-free precursor is Ni 1- x Mn x (OH) 2 and 0.45 ⁇ x ⁇ 0.55.
  • the second sintering process includes: subjecting the cobalt-free single crystal material, the boron coating agent and the carbon coating agent to a second mixing process to obtain a second mixture; sintering the second mixture, A cobalt-free cathode material is obtained.
  • the cobalt-free single crystal material is mixed with the boron coating agent and the carbon coating agent, so that the three can be mixed more uniformly to obtain a second mixture. Sintering the second mixture can form a boron carbide coating layer on the surface of the cobalt-free single crystal material.
  • the preparation of cobalt-free cathode material by the above method can not only improve its wear resistance, corrosion resistance and electrical conductivity, but also further Improve its capacitance and cycle performance.
  • the second mixing process is performed at a stirring speed of 2000-3000 rpm, and the mixing time is 10-20 minutes.
  • the preparation method further includes: sieving the product obtained by the dry coating process to remove particles with a particle size ⁇ 0.2 ⁇ m and particles with a particle size ⁇ 6 ⁇ m to obtain a cobalt-free cathode material. Screening the products obtained by the dry coating process is beneficial to improve the stability of the electrical properties of the cobalt-free cathode material.
  • the cobalt-free cathode material coated with boron carbide can be obtained through the second sintering process.
  • the temperature of the second sintering treatment process is 300-900°C, and the treatment time is 10-20 min.
  • the temperature and processing time of the second sintering process include but are not limited to the above range, and limiting it to the above range is beneficial to further increase the sintering degree and improve the overall performance of the cobalt-free cathode material. More preferably, the D50 of the cobalt-free precursor is 0.5-2 ⁇ m.
  • the addition of the boron coating agent and the carbon coating agent can improve the conductivity, cycle performance and capacitance of the cobalt-free positive electrode material.
  • the boron coating agent includes but is not limited to one or more of the group consisting of boric acid, boron oxide, boron nitrate and metaboric acid
  • the carbon coating agent includes but is not limited to sucrose, glucose, One or more of the group consisting of polyethylene glycol (PEG) and titanium carbide (TiC).
  • the above-mentioned several have the advantages of low cost and wide sources, so the selection of the above-mentioned several boron coating agents and carbon coating agents is beneficial to reduce the preparation cost.
  • the carbon coating agent is TiC.
  • the cobalt-free cathode material can be represented by LiNi 1-x Mn x O 2 , 0.45 ⁇ x ⁇ 0.55, and the cobalt-free cathode material is prepared by the above-mentioned preparation method.
  • the layered cobalt-free cathode material LiNi 1-x Mn x O 2 (0.45 ⁇ x ⁇ 0.55) is prepared by sintering the lithium source material and the lithium manganese precursor, and then the layered cathode material can be obtained by crushing it to 1 ⁇ 2 ⁇ m Of cobalt-free single crystal materials.
  • the surface of the layered cobalt-free single crystal material can fully contact and react with the electrolyte, and form a stable positive solid electrolyte interface membrane (SEI) during the initial cycle.
  • SEI solid electrolyte interface membrane
  • the above-mentioned cobalt-free single crystal material can greatly reduce gas production during the application process and improve the cycle performance of the material.
  • its particle size is limited to 1 ⁇ 2 ⁇ m, which is lower than ordinary secondary particles (approximately 10 ⁇ m) and ordinary single crystal materials (approximately 3 ⁇ 4 ⁇ m) This is beneficial to greatly improve the current rate performance of the cobalt-free cathode material.
  • sintering the cobalt-free single crystal material with a boron coating agent and a carbon coating agent can form a boron carbide coating layer on the surface of the cobalt-free single crystal material.
  • Boron carbide not only has good electrical conductivity, but also has high strength and chemical stability.
  • the cobalt-free cathode material prepared by the above method has the advantages of stable structure, high capacitance, excellent current rate performance and good cycle performance.
  • the coating amount of C element is 0.1 to 3%, and the coating amount of B element is 0.01 to 1%. Limiting the coating amount of C element and B element within the above range can make it play a better synergistic effect with lithium element, nickel element and manganese element, thereby enabling the cobalt-free cathode material to have more excellent electrical properties and Corrosion resistance and wear resistance.
  • Another aspect of the present application also provides a lithium ion battery, including a positive electrode material, and the positive electrode material includes the aforementioned cobalt-free positive electrode material.
  • the cobalt-free cathode material provided in this application has the advantages of stable structure, high capacitance, excellent current rate performance, and good cycle performance. Therefore, using it as a lithium-ion battery can greatly improve its capacity, current rate performance and cycle performance.
  • the bulk material sintered by the reaction is crushed by a jet mill, and most of the single crystal particle products with a particle size of 1-2 microns are obtained.
  • Dry coating is used to coat the above-mentioned single crystal particles with boron and carbon.
  • the specific process is: adding the coating agent and the single crystal particle product to a 5L mixing equipment for mixing. Mixing time: 15 minutes, rotation speed: 2500rpm; Among them, the boron coating agent includes boric acid, and the carbon coating agent includes sucrose. After high temperature treatment at 400°C in an inert atmosphere (nitrogen) for 6 hours, the coated carbon content after high temperature treatment is 1% (wt), and the boron coating The content is 0.1% (wt). Finally, the high-temperature processed material is air-classified and sieved with 350 meshes to remove powders below 0.2 microns and greater than 6 microns to obtain the final product, a cobalt-free cathode material.
  • FIG. 7 shows a scanning electron microscope image of a cobalt-free cathode material without a coating layer at a high magnification of 20000 times.
  • a four-probe tester was used to detect the resistivity of 2 ⁇ m uncoated cobalt-free single crystal material, 2 ⁇ m coated cobalt-free single crystal material, and 5 ⁇ m uncoated cobalt-free single crystal material.
  • the results are shown in Figure 4. It can be seen from Figure 4 that compared to 5 ⁇ m uncoated and cobalt-free single crystal materials, the resistivity of 2 ⁇ m uncoated and cobalt-free single crystal materials and 2 ⁇ m coated and cobalt-free single crystal materials is lower.
  • the particle size is limited to 2 ⁇ m, and carbon-boron coating can improve the conductivity of the cobalt-free cathode material.
  • Example 1 The difference from Example 1 is that the temperature of the first sintering process is 700°C, and the temperature of the second sintering process is 900°C.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 cycles is 93%, and the discharge capacity is 210m Ah/g.
  • Example 2 The difference from Example 1 is that the temperature of the first sintering process is 1200°C, and the temperature of the second sintering process is 300°C.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 cycles is 97%, and the discharge capacity is 198mAh/g.
  • Example 1 The difference from Example 1 is that the temperature of the first sintering process is 600°C.
  • the cobalt-free cathode material has a capacity retention rate of 80% at 45°C for 600 cycles, and a discharge capacity of 180mAh/g.
  • Example 2 The difference from Example 1 is that the temperature of the second sintering process is 200°C.
  • the cobalt-free cathode material has a capacity retention rate of 82% at 45°C for 600 weeks and a discharge capacity of 179mAh/g.
  • Example 1 The difference from Example 1 is that the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor is 0.95:1.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 weeks was 93%, and the discharge capacity was 201 mAh/g.
  • Example 1 The difference from Example 1 is that the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor is 1.10:1.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 weeks is 96%, and the discharge capacity is 200 mAh/g.
  • Example 1 The difference from Example 1 is that the ratio of the number of moles of Li element in the lithium source material to the sum of the number of moles of Ni element and Mn element in the cobalt-free precursor is 1.5:1.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45° C. for 600 weeks was 91%, and the discharge capacity was 188 mAh/g.
  • Example 1 The difference from Example 1 is that after the second sintering treatment, the screening process is not performed.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45° C. for 600 weeks was 89%, and the discharge capacity was 200 mAh/g.
  • Example 1 The difference from Example 1 is that the coating amount of C element is 4%, and the coating amount of B element is 2%.
  • the cobalt-free cathode material has a cycle capacity retention rate of 92% at 45° C. for 600 weeks and a discharge capacity of 180 mAh/g.
  • Example 1 The difference from Example 1 is that the carbon coating agent is TiC.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 weeks is 96%, and the discharge capacity is 205m Ah/g.
  • Example 2 The difference from Example 1 is that after crushing, the particle size of the cobalt-free single crystal material is 5 ⁇ m.
  • the cycle capacity retention rate of the cobalt-free cathode material at 45°C for 600 cycles is 93%, and the discharge capacity is 180m Ah/g.
  • Example 2 The difference from Example 1 is that there is only a carbon coating layer.
  • the cobalt-free cathode material has a cycle capacity retention rate of 90% at 45°C for 600 weeks, and a discharge capacity of 200mAh/g.
  • Example 1 The difference from Example 1 is that there is only a boron coating layer.
  • the cobalt-free cathode material has a cycle capacity retention rate of 85% at 45°C for 600 weeks, and a discharge capacity of 180mAh/g.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Inorganic Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Metallurgy (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)

Abstract

一种无钴正极材料、其制备方法及锂离子电池。该制备方法包括：将锂源材料与无钴前驱体进行第一烧结处理，得到烧结产物；使烧结产物破碎至1～2μm，得到无钴单晶材料；及将无钴单晶材料、硼包覆剂及碳包覆剂进行第二烧结处理，得到无钴正极材料。采用上述方法制得无钴正极材料具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。

Description

无钴正极材料、其制备方法及锂离子电池 技术领域
本发明涉及锂离子电池领域，具体而言，涉及一种无钴正极材料、其制备方法及锂离子电池。
背景技术
不含钴的正极材料是锂离子电池领域较为关注的对象，其中，镍锰层状材料因具有能量密度高、成本较低及循环性能好等优势，已经成为近年来的研究热点。但研究发现镍含量较高(摩尔百分比大于80％)的镍锰层状结构存在结构不稳定、安全性较差、循环性能较差、碱性高及与电解液之间的副反应多导致产气等问题，这导致镍锰层状材料的实际应用受到限制。
由于镍锰正极材料中不含有钴元素，且镍元素含量低、锰元素含量高，因此该材料的导电性较差，容量会比较低。根据现有文献可知，采用掺杂Ti的LiNi 0.5Mn 0.5-xTi xO 2可以在一定程度上改善正极材料的导电性，将电容量从150mAh/g提升到180mAh/g，但此电容量仍远低于目前高镍正极材料的200～210mAh/g等。另一篇现有文献也提供了一种LiNi 0.5Mn 0.5O 2材料的改进方法，其包括通过掺杂硅元素，正极材料的电容量可以提升至192mAh/g，但循环性能还不理想，100周循环保持率最高只有78％。
鉴于上述问题的存在，有必要研发一种电容量高和循环性能好的无钴正极材料。
发明内容
本发明的主要目的在于提供一种无钴正极材料、其制备方法及锂离子电池，以解决现有锂离子电池正极材料存在电容量高，但循环性能较差的问题。
为了实现上述目的，本发明一方面提供了一种无钴正极材料的制备方法，该制备方法包括：将锂源材料与无钴前驱体进行第一烧结处理，得到烧结产物；使烧结产物破碎至1～2μm，得到无钴单晶材料；及将无钴单晶材料、硼包覆剂及碳包覆剂进行第二烧结处理，得到无钴正极材料。
进一步地，第一烧结处理过程包括：将锂源材料与无钴前驱体进行第一混合处理，得到第一混合物；在空气或氧气气氛存在下，使第一混合物进行烧结，得到烧结产物；优选地，第一混合处理过程在2000～3000rpm的搅拌速度下进行，混合时间为5～20min。
进一步地，第一烧结处理过程的温度为700～1200℃，烧结时间为5～15h；优选地，第一烧结处理过程的温度为900～1000℃。
进一步地，锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为(0.95～1.10):1。
进一步地，锂源材料为氢氧化锂、碳酸锂、醋酸锂、氧化锂、硝酸锂和草酸锂组成的组中的一种或多种；无钴前驱体为Ni 1-xMn x(OH) 2所示的化合物，且0.45≤x≤0.55；硼包覆剂选自硼酸、氧化硼、硝酸硼和偏硼酸组成的组中的一种或多种，碳包覆剂选自蔗糖、葡萄糖、PEG和TiC组成的组中的一种或多种。
进一步地，第二烧结处理过程包括：使无钴单晶材料与硼包覆剂及碳包覆剂进行第二混合处理，得到第二混合物；将第二混合物进行烧结，得到无钴正极材料；优选地，制备方法还包括：将第二烧结处理过程得到的产物进行筛分，以去除粒度≤0.2μm的颗粒和粒度≥6μm的颗粒，得到无钴正极材料；优选地，第二混合处理过程在2000～3000rpm的搅拌速度下进行，混合时间为10～20min。
进一步地，第二烧结处理过程的温度为300～900℃，处理时间为10～20min；优选地，无钴前驱体的D50为0.5～2μm。
本申请的另一方面还提供了一种无钴正极材料，该无钴正极材料采用上述制备方法制得。
进一步地，无钴正极材料中，C元素的包覆量为0.1～3％，B元素的包覆量为0.01～1％。
本申请的又一方面还提供了一种锂离子电池，包括正极材料，正极材料包括上述无钴正极材料。
应用本发明的技术方案，以锂源材料与无钴前驱体进行烧结制得层状的无钴正极材料LiNi 1-xMn xO 2(0.45≤x≤0.55)，然后通过将其破碎至1～2μm，能够获得层状的无钴单晶材料。在初始的充放电过程中，层状的无钴单晶材料表面可以和电解液充分接触反应，并在初始循环中形成稳定的正极固态电解质界面膜(SEI)。而在后期循环的充放电的收缩膨胀不会像多晶形貌颗粒产生新的晶界界面，也不会发生副反应。因而上述无钴单晶材料在应用过程中能够大大减少产气，并提高材料的循环性能。同时由于无钴正极材料本身的导电性较差，容量较低，将其粒径限定在1～2μm之间，低于普通二次颗粒(大约10μm)和一般单晶材料(大约3～4μm)，这样有利于大幅提高相比于含钴正极材料，锂材料的电流倍率性能。此外，将无钴单晶材料与硼包覆剂及碳包覆剂进行烧结，能够在无钴单晶材料表面形成碳化硼包覆层。碳化硼不仅具有良好的导电性，而且还具有较高的强度和化学稳定性。在上述三方面原因的基础上，采用上述方法制得无钴正极材料具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。
附图说明
构成本申请的一部分的说明书附图用来提供对本发明的进一步理解，本发明的示意性实施例及其说明用于解释本发明，并不构成对本发明的不当限定。在附图中：
图1示出了根据本发明实施例1中经破碎处理得到的产物的2000倍扫描电子显微镜图；
图2示出了根据本发明实施例1制得的无钴正极材料的XRD图；
图3示出了根据本发明实施例1制得的无钴正极材料在30000倍高倍率下的扫描电子显微镜图；
图4示出了根据本发明实施例1制得的2μm无包覆无钴单晶材料、2μm包覆无钴单晶材料以及5μm无包覆无钴单晶材料的电阻率；
图5示出了根据本发明实施例1制得的无钴正极材料的充放电曲线；
图6示出了根据本发明实施例1制得的无钴正极材料在45℃下的循环曲线；
图7示出了没有包覆层的无钴正极材料在20000倍高倍率下的扫描电子显微镜图。
具体实施方式
需要说明的是，在不冲突的情况下，本申请中的实施例及实施例中的特征可以相互组合。下面将结合实施例来详细说明本发明。
正如背景技术所描述的，现有锂离子电池正极材料存在电容量高，但循环性能较差的问题。为了解决上述技术问题，本申请提供了一种无钴正极材料的制备方法，该制备方法包括：将锂源材料与无钴前驱体进行第一烧结处理，得到烧结产物；使烧结产物破碎至1～2μm，得到无钴单晶材料；将无钴单晶材料与硼包覆剂及碳包覆剂进行第二烧结处理，得到无钴正极材料。
以锂源材料与无钴前驱体进行烧结制得层状的无钴正极材料LiNi 1-xMn xO 2(0.45≤x≤0.55)，然后通过将其破碎至1～2μm，能够获得层状的无钴单晶材料。在初始的充放电过程中，层状的无钴单晶材料表面可以和电解液充分接触反应，并在初始循环中形成稳定的正极固态电解质界面膜(SEI)。而在后期循环的充放电的收缩膨胀不会像多晶形貌颗粒产生新的晶界界面，也不会发生副反应。因而上述无钴单晶材料在应用过程中能够大大减少产气，并提高材料的循环性能。同时由于相比于含钴正极材料，无钴正极材料本身的导电性较差，容量较低，将其粒径限定在1～2μm之间，低于普通二次颗粒(大约10μm)和一般单晶材料(大约3～4μm)，这样有利于大幅提高无钴正极材料的电流倍率性能。此外，将无钴单晶材料与硼包覆剂及碳包覆剂进行烧结，能够在无钴单晶材料表面形成碳化硼包覆层。碳化硼不仅具有良好的导电性，而且还具有较高的强度和化学稳定性。在上述三方面原因的基础上，采用上述方法制得无钴正极材料具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。
上述烧结过程为有氧烧结过程，可以采用本领域常用的装置和工艺实现。在一种优选的实施例中，上述烧结过程包括：将锂源材料与无钴前驱体进行第一混合处理，得到第一混合物；在空气或氧气气氛存在下，使第一混合物进行烧结，得到烧结产物。在进行烧结过程之前，先将锂源材料和无钴前驱体进行混合有利于提高两种原料的混合均匀性以及烧结程度，从而有利于提高层状的无钴正极材料的稳定性。为了进一步提高层状的无钴正极材料的稳定性，优选地，第一混合处理过程在2000～300rpm的搅拌速度下进行，混合时间为5～20min。
在一种优选的实施例中，第一烧结处理过程的温度为700～1200℃，烧结时间为5～15h。第一烧结处理的温度和烧结时间包括但不限于上述范围，而将其限定在上述范围内有利于进一步提高层状的无钴正极材料的稳定性。更优选地，第一烧结处理过程的温度为900～1000℃。
采用上述制备方法制得的镍锰锂电池具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。在一种优选的实施例中，锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为(0.95～1.10):1。将锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值限定在上述范围内有利于进一步提高正极材料的能量密度和电容量及结构稳定性。
上述制备方法中，锂源材料和无钴前驱体可以选用本领域常用的种类。在一种优选的实施例中，锂源材料为氢氧化锂、碳酸锂、醋酸锂、氧化锂、硝酸锂和草酸锂组成的组中的一种或多种；无钴前驱体为Ni 1-xMn x(OH) 2所示的化合物，且0.45≤x≤0.55。
在一种优选的实施例中，第二烧结处理过程包括：使无钴单晶材料与硼包覆剂及碳包覆剂进行第二混合处理，得到第二混合物；将第二混合物进行烧结，得到无钴正极材料。将无钴单晶材料与硼包覆剂及碳包覆剂进行混合，能够使三者混合地更加均匀，得到第二混合物。将第二混合物进行烧结，能够在无钴单晶材料表面形成碳化硼包覆层。由于碳化硼不仅具有良好的导电性，而且还具有较高的强度和化学稳定性，因而采用上述方法制备无钴正极材料不仅能够提高其耐磨损性、耐腐蚀性和导电性，还能够进一步提高其电容量和循环性能。为了进一步提高碳化硼包覆层的均匀性，提高无钴正极材料的稳定性，更优选地，第二混合处理过程在2000～3000rpm的搅拌速度下进行，混合时间为10～20min。
在一种优选的实施例中，制备方法还包括：将干法包覆过程得到的产物进行筛分，以去除粒度≤0.2μm的颗粒和粒度≥6μm的颗粒，得到无钴正极材料。对干法包覆过程得到的产物进行筛选有利于提高无钴正极材料的电学性能的稳定性。
通过第二烧结过程能够获得碳化硼包覆的无钴正极材料。在一种优选的实施例中，第二烧结处理过程的温度为300～900℃，处理时间为10～20min。第二烧结处理过程的温度和处理时间包括但不限于上述范围，而将其限定在上述范围内有利于进一步提高烧结程度，提高无钴正极材料的综合性能。更优选地，无钴前驱体的D50为0.5～2μm。
上述制备方法中，硼包覆剂和碳包覆剂的加入可以提高无钴正极材料的导电性、循环性能和电容量。在一种优选的实施例中，硼包覆剂包括但不限于硼酸、氧化硼、硝酸硼和偏硼酸组成的组中的一种或多种，碳包覆剂包括但不限于蔗糖、葡萄糖、聚乙二醇(PEG)和碳化钛(TiC)组成的组中的一种或多种。相比于其它硼包覆剂和碳包覆剂，上述几种具有成本低和来源广等优点，因而选用上述几种硼包覆剂和碳包覆剂有利于降低制备成本。为了进一步提高无钴正极材料的导电性，更优选地，碳包覆剂为TiC。
本申请的另一方面还提供了一种无钴正极材料，无钴正极材料可以采用LiNi 1-xMn xO 2表示，0.45≤x≤0.55，且无钴正极材料采用上述制备方法制得。
以锂源材料与锂锰前驱体进行烧结制得层状的无钴正极材料LiNi 1-xMn xO 2(0.45≤x≤0.55)，然后通过将其破碎至1～2μm，能够获得层状的无钴单晶材料。在初始的充放电过程中，层状的无钴单晶材料表面可以和电解液充分接触反应，并在初始循环中形成稳定的正极固态电解质界面膜(SEI)。而在后期循环的充放电的收缩膨胀不会像多晶形貌颗粒产生新的晶界界面，也不会发生副反应。因而上述无钴单晶材料在应用过程中能够大大减少产气，并提高材料的循环性能。同时由于无钴正极材料本身的导电性较差，容量较低，将其粒径限定在1～2μm之间，低于普通二次颗粒(大约10μm)和一般单晶材料(大约3～4μm)，这样有利于大幅提高无钴正极材料的电流倍率性能。此外，将无钴单晶材料与硼包覆剂及碳包覆剂进行烧结，能够在无钴单晶材料表面形成碳化硼包覆层。碳化硼不仅具有良好的导电性，而且还具有较高的强度和化学稳定性。在上述三方面原因的基础上，采用上述方法制得无钴正极材料具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。
优选地，C元素的包覆量为0.1～3％，B元素的包覆量为0.01～1％。将C元素及B元素的包覆量限定在上述范围内能够使其与锂元素、镍元素及锰元素发挥更好的协同增效作用，从而能够使无钴正极材料具有更加优异的电学性能和耐腐蚀及耐磨损性能。
本申请的又一方面还提供了一种锂离子电池，包括正极材料，正极材料包括上述无钴正极材料。
本申请提供的无钴正极材料具有结构稳定、电容量高、电流倍率性能优和循环性能好等优点。因而采用其作为锂离子电池能够大大提高其电容量、电流倍率性能和循环性能。
以下结合具体实施例对本申请作进一步详细描述，这些实施例不能理解为限制本申请所要求保护的范围。
实施例1
先将氢氧化锂和D50粒径在1.5微米的前驱体Ni 1-xMn x(OH) 2(0.45≤x≤0.55)，按Li/(Ni+Mn)的摩尔比为1.05进行称量，然后采用高速混合设备进行混合，混合时间在10分钟。实验室5L设备转速在2500rpm，设备中的物料填充效率在50％。
在1000℃高温反应10小时(氧气)，将反应烧结出来的块状物料采用气流磨进行破碎，得到大部分粒径在1-2微米的单晶颗粒产品。
采用干法包覆，对上述单晶颗粒进行硼和碳共包覆，具体过程为：将包覆剂与单晶颗粒产品一起加入到5L混合设备中进行混合，混合时间：15分钟，转速：2500rpm；其中，硼包覆剂包括硼酸，碳包覆剂包括蔗糖，在400度惰性气氛(氮气)高温处理6小时，高温处理后包覆的碳含量为1％(wt)，硼的包覆含量为0.1％(wt)。最后将高温处理后的物料进行气流分级和350目过筛，去除0.2微米以下和大于6微米的粉体，得到最终产品无钴正极材料。
采用Zeiss扫描电镜对经破碎处理得到的产物进行检测，图谱见图1；由图1可知，无钴单晶材料为2μm单晶颗粒。图7示出了没有包覆层的无钴正极材料在20000倍高倍率下的扫描电子显微镜图。
采用XRD衍射仪对无钴正极材料的组成进行检测，谱图见图2；由图2可知，无钴正极材料属于六方晶系，R3-m空间群，为层状结构。
无钴正极材料在30000倍高倍率下的扫描电子显微镜(SEM)照片见图3，由图3可以明显看出，单晶颗粒表面有明显的包覆物质。
采用四探针测试仪对2μm无包覆无钴单晶材料、2μm包覆无钴单晶材料以及5μm无包覆无钴单晶材料的电阻率进行检测，结果见图4。由图4可知，相比于5μm无包覆无钴单晶材料，2μm无包覆无钴单晶材料和2μm包覆无钴单晶材料的电阻率更低，因而将无钴单晶材料的粒度限定在2μm，且对其进行碳硼包覆能够提高无钴正极材料的导电性。
采用国家GB/T 23365-2009 GB/T23366-2009的方法测试无钴正极材料的充放电性能，充放电曲线见图5。由图5可知，采用本申请提供的方法制得的无钴正极材料的电容量高，可以达到203mAh/g。
采用GB/T23366-2009的方法测试无钴正极材料的循环性能，测试结果见图6。由图6可知，采用本申请提供的方法制得的无钴正极材料的循环性能好，600周45℃循环容量保持率为95％。
实施例2
与实施例1的区别为：第一烧结过程的温度为700℃，第二烧结过程的温度为900℃。
无钴正极材料的在600周45℃循环容量保持率为93％，放电容量为210m Ah/g。
实施例3
与实施例1的区别为：第一烧结过程的温度为1200℃，第二烧结过程的温度为300℃。
无钴正极材料的在600周45℃循环容量保持率为97％，放电容量为198m Ah/g。
实施例4
与实施例1的区别为：第一烧结过程的温度为600℃。
无钴正极材料的在600周45℃循环容量保持率为80％，放电容量为180mAh/g。
实施例5
与实施例1的区别为：第二烧结过程的温度为200℃。
无钴正极材料的在600周45℃循环容量保持率为82％，放电容量为179mAh/g。
实施例6
与实施例1的区别为：锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为0.95:1。
无钴正极材料的在600周45℃循环容量保持率为93％，放电容量为201mAh/g。
实施例7
与实施例1的区别为：锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为1.10:1。
无钴正极材料的在600周45℃循环容量保持率为96％，放电容量为200mAh/g。
实施例8
与实施例1的区别为：锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为1.5:1。
无钴正极材料的在600周45℃循环容量保持率为91％，放电容量为188mAh/g。
实施例9
与实施例1的区别为：第二烧结处理后，不进行筛分过程。
无钴正极材料的在600周45℃循环容量保持率为89％，放电容量为200mAh/g。
实施例10
与实施例1的区别为：C元素的包覆量为4％，B元素的包覆量为2％。
无钴正极材料的在600周45℃循环容量保持率为92％，放电容量为180mAh/g。
实施例11
与实施例1的区别为：碳包覆剂为TiC。
无钴正极材料的在600周45℃循环容量保持率为96％，放电容量为205m Ah/g。
对比例1
与实施例1的区别为：经破碎后，无钴单晶材料的粒度为5μm。
无钴正极材料的在600周45℃循环容量保持率为93％，放电容量为180m Ah/g。
对比例2
与实施例1的区别为：只有碳包覆层。
无钴正极材料在600周45℃循环容量保持率为90％，放电容量为200mAh/g。
对比例3
与实施例1的区别为：只有硼包覆层。
无钴正极材料在600周45℃循环容量保持率为85％，放电容量为180mAh/g。
从以上的描述中，可以看出，本发明上述的实施例实现了如下技术效果：
比较实施例1至11及对比例1至3可知，采用本申请提供的方法制得的无钴正极材料具有更加优异的循环性能和电容量。
比较实施例1至5可知，将第一烧结处理和第二烧结处理过程的温度限定在本申请优选的范围内有利于进一步提高无钴正极材料的循环性能和电容量。
比较实施例1、6至8可知，将锂源材料中Li元素的摩尔数与无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值限定在本申请优选的范围内有利于进一步提高无钴正极材料的循环性能和电容量。
比较实施例1、10至11可知，采用本申请优选的包覆剂有利于提高无钴正极材料的循环性能和电容量。
需要说明的是，本申请的说明书和权利要求书中的术语“第一”、“第二”等是用于区别类似的对象，而不必用于描述特定的顺序或先后次序。应该理解这样使用的术语在适当情况下可以互换，以便这里描述的本申请的实施方式例如能够以除了在这里描述的那些以外的顺序实施。
以上所述仅为本发明的优选实施例而已，并不用于限制本发明，对于本领域的技术人员来说，本发明可以有各种更改和变化。凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。

Claims (10)

  1. 一种无钴正极材料的制备方法，其特征在于，所述制备方法包括：
    将锂源材料与无钴前驱体进行第一烧结处理，得到烧结产物；
    使所述烧结产物破碎至1～2μm，得到无钴单晶材料；及
    将所述无钴单晶材料、硼包覆剂及碳包覆剂进行第二烧结处理，得到所述无钴正极材料。
  2. 根据权利要求1的制备方法，其特征在于，所述第一烧结处理过程包括：
    将所述锂源材料与所述无钴前驱体进行第一混合处理，得到第一混合物；
    在空气或氧气气氛下，使所述第一混合物进行烧结，得到所述烧结产物；
    优选地，所述第一混合处理过程在2000～3000rpm的搅拌速度下进行，混合时间为5～20min。
  3. 根据权利要求1或2的制备方法，其特征在于，所述第一烧结处理过程的温度为700～1200℃，烧结时间为5～15h；优选地，所述第一烧结处理过程的温度为900～1000℃。
  4. 根据权利要求3的制备方法，其特征在于，所述锂源材料中Li元素的摩尔数与所述无钴前驱体中Ni元素和Mn元素的摩尔数之和的比值为(0.95～1.10):1。
  5. 根据权利要求1的制备方法，其特征在于，所述锂源材料为氢氧化锂、碳酸锂、醋酸锂、氧化锂、硝酸锂和草酸锂组成的组中的一种或多种；所述无钴前驱体为Ni 1-xMn x(OH) 2所示的化合物，且0.45≤x≤0.55；所述硼包覆剂选自硼酸、氧化硼、硝酸硼和偏硼酸组成的组中的一种或多种，所述碳包覆剂选自蔗糖、葡萄糖、聚乙二醇和碳化钛组成的组中的一种或多种。
  6. 根据权利要求1至5中任一项的制备方法，其特征在于，所述第二烧结处理过程包括：
    使所述无钴单晶材料与所述硼包覆剂及所述碳包覆剂进行第二混合处理，得到第二混合物；
    将所述第二混合物进行烧结，得到无钴正极材料；
    优选地，所述制备方法还包括：将所述第二烧结处理过程得到的产物进行筛分，以去除粒度≤0.2μm的颗粒和粒度≥6μm的颗粒，得到所述无钴正极材料；
    优选地，所述第二混合处理过程在2000～3000rpm的搅拌速度下进行，混合时间为10～20min。
  7. 根据权利要求6的制备方法，其特征在于，所述第二烧结处理过程的温度为300～900℃，处理时间为10～20min；
    优选地，所述无钴前驱体的D50为0.5～2μm。
  8. 一种无钴正极材料，其特征在于，所述无钴正极材料采用权利要求1至7中任一项所述的制备方法制得。
  9. 根据权利要求8的无钴正极材料，其特征在于，所述无钴正极材料中，C元素的包覆量为0.1～3％，B元素的包覆量为0.01～1％。
  10. 一种锂离子电池，包括正极材料，其特征在于，所述正极材料包括权利要求8或9所述的无钴正极材料。
PCT/CN2020/124466 2020-05-25 2020-10-28 无钴正极材料、其制备方法及锂离子电池 WO2021238051A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2022514560A JP7369277B2 (ja) 2020-05-25 2020-10-28 コバルトフリー正極材料、その製造方法及びリチウムイオン電池
EP20937309.1A EP3975292A4 (en) 2020-05-25 2020-10-28 COBALT-FREE POSITIVE ELECTRODE MATERIAL, PROCESS FOR ITS PRODUCTION AND LITHIUM-ION BATTERY
US17/763,664 US20240055577A1 (en) 2020-05-25 2020-10-28 Cobalt-free positive electrode material, preparation method thereof and lithium ion battery
KR1020227005073A KR20220035191A (ko) 2020-05-25 2020-10-28 무-코발트 양극 재료, 이의 제조 방법 및 리튬 이온 전지

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010451704.6A CN111599999B (zh) 2020-05-25 2020-05-25 无钴正极材料、其制备方法及锂离子电池
CN202010451704.6 2020-05-25

Publications (1)

Publication Number Publication Date
WO2021238051A1 true WO2021238051A1 (zh) 2021-12-02

Family

ID=72184161

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/124466 WO2021238051A1 (zh) 2020-05-25 2020-10-28 无钴正极材料、其制备方法及锂离子电池

Country Status (6)

Country Link
US (1) US20240055577A1 (zh)
EP (1) EP3975292A4 (zh)
JP (1) JP7369277B2 (zh)
KR (1) KR20220035191A (zh)
CN (1) CN111599999B (zh)
WO (1) WO2021238051A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114975981A (zh) * 2022-05-25 2022-08-30 泾河新城陕煤技术研究院新能源材料有限公司 一种镍基无钴正极材料及其制备方法
CN114975983A (zh) * 2022-05-06 2022-08-30 四川新锂想能源科技有限责任公司 高镍低钴材料及其制备方法、电池正极
CN117558904A (zh) * 2024-01-11 2024-02-13 河南科隆新能源股份有限公司 一种多孔核壳结构无钴正极材料及其制备方法

Families Citing this family (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111599999B (zh) * 2020-05-25 2022-04-08 蜂巢能源科技股份有限公司 无钴正极材料、其制备方法及锂离子电池
CN112582597A (zh) * 2020-11-20 2021-03-30 昆明理工大学 一种三元无钴正极材料的制备方法及改性方法
CN113060774B (zh) * 2021-03-26 2023-04-07 蜂巢能源科技有限公司 一种无钴正极材料及其制备方法和应用
CN113072101B (zh) * 2021-03-30 2023-04-07 蜂巢能源科技有限公司 一种无钴正极材料及其制备方法和应用
CN113023794B (zh) * 2021-03-31 2023-05-23 蜂巢能源科技有限公司 无钴高镍正极材料及其制备方法、锂离子电池正极及锂离子电池
CN113292111A (zh) * 2021-04-23 2021-08-24 陕西彩虹新材料有限公司 一种无钴单晶正极材料及其制备方法
CN114094059B (zh) * 2021-09-28 2023-04-28 格林美(湖北)新能源材料有限公司 一种复合纳米层包覆的无钴单晶正极材料及其制备方法
CN113998745B (zh) * 2021-12-27 2022-04-01 蜂巢能源科技股份有限公司 一种无钴正极材料及其制备方法和应用
CN114566620B (zh) * 2022-01-26 2024-02-02 泾河新城陕煤技术研究院新能源材料有限公司 锂电池高镍无钴单晶正极材料及其制备方法
WO2023162694A1 (ja) * 2022-02-28 2023-08-31 パナソニックＩｐマネジメント株式会社 非水電解質二次電池用正極活物質及び非水電解質二次電池
CN114808127B (zh) * 2022-05-23 2023-11-17 宁波容百新能源科技股份有限公司 一种无钴单晶材料及其制备方法和应用
CN114988497B (zh) * 2022-08-08 2022-11-29 蜂巢能源科技股份有限公司 细化无钴正极材料的方法、无钴正极材料和锂离子电池

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102339999A (zh) * 2010-07-14 2012-02-01 中国科学院物理研究所 一种聚阴离子复合材料及其制备方法和用途
CN103280569A (zh) * 2013-02-04 2013-09-04 刘剑洪 一种类石墨烯包覆富锂层状镍锰酸锂及制备方法和应用
CN109811412A (zh) * 2018-12-28 2019-05-28 广东邦普循环科技有限公司 一种单晶形貌的层状镍锰酸锂正极材料及其制备方法
CN110304665A (zh) * 2019-07-11 2019-10-08 兰州理工大学 一种微米级单晶镍锰酸锂正极材料的制备方法
CN111599999A (zh) * 2020-05-25 2020-08-28 蜂巢能源科技有限公司 无钴正极材料、其制备方法及锂离子电池

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3653409B2 (ja) * 1999-01-29 2005-05-25 三洋電機株式会社 リチウム二次電池用正極活物質及びその製造方法、この正極活物質を用いたリチウム二次電池用正極及びその製造方法、この正極を用いたリチウム二次電池及びその製造方法
CN1826291A (zh) * 2003-07-18 2006-08-30 东曹株式会社 锂－镍－锰复合氧化物、其制造方法及用途
JP5229472B2 (ja) * 2007-11-12 2013-07-03 戸田工業株式会社 非水電解液二次電池用マンガン酸リチウム粒子粉末及びその製造方法、並びに非水電解液二次電池
JP2011171113A (ja) * 2010-02-18 2011-09-01 Sanyo Electric Co Ltd リチウム二次電池用正極活物質及びその製造方法並びにそれを用いたリチウム二次電池
KR20120056674A (ko) * 2010-11-25 2012-06-04 삼성에스디아이 주식회사 리튬 이차 전지용 양극 활물질, 이의 제조 방법 및 이를 포함하는 리튬 이차 전지
JP5803539B2 (ja) * 2011-10-11 2015-11-04 株式会社豊田自動織機 リチウム含有複合酸化物粉末の製造方法
JP6536141B2 (ja) * 2015-04-14 2019-07-03 トヨタ自動車株式会社 複合活物質の製造方法
WO2018047946A1 (ja) * 2016-09-12 2018-03-15 富士フイルム株式会社 電極層材、全固体二次電池電極用シートおよび全固体二次電池ならびに全固体二次電池用電極シートおよび全固体二次電池の製造方法
CN107804879B (zh) * 2017-10-18 2019-11-19 重庆特瑞新能源材料有限公司 一种纳米化制备单晶锂电池正极材料的方法
CN108598457A (zh) * 2018-04-23 2018-09-28 桑德集团有限公司 一种单晶富锂锰基正极材料及其制备方法、锂离子电池
CN110660961B (zh) * 2018-06-28 2021-09-21 宁德时代新能源科技股份有限公司 正极片及锂离子电池
CN109148847B (zh) * 2018-08-07 2021-04-09 湖州杉杉新能源科技有限公司 一种具有高倍率性能的硼掺杂改性的硬碳包覆负极材料及其液相制备方法
CN109019605B (zh) * 2018-09-25 2022-03-11 通辽中硼新材料科技有限公司 一种碳化硼材料的冶炼方法
CN109755513B (zh) * 2018-12-26 2021-08-31 格林美（无锡）能源材料有限公司 金属硒化物/c/b复合包覆的正极材料及其制备方法
CN109962223A (zh) * 2019-03-07 2019-07-02 浙江超威创元实业有限公司 一种包含无钴Ni-Mn固溶镍基正极材料的锂离子电池
CN110444762B (zh) * 2019-07-12 2022-08-19 格林美（无锡）能源材料有限公司 有机粘结膜负载活性炭和硼共包覆的正极材料及制备方法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102339999A (zh) * 2010-07-14 2012-02-01 中国科学院物理研究所 一种聚阴离子复合材料及其制备方法和用途
CN103280569A (zh) * 2013-02-04 2013-09-04 刘剑洪 一种类石墨烯包覆富锂层状镍锰酸锂及制备方法和应用
CN109811412A (zh) * 2018-12-28 2019-05-28 广东邦普循环科技有限公司 一种单晶形貌的层状镍锰酸锂正极材料及其制备方法
CN110304665A (zh) * 2019-07-11 2019-10-08 兰州理工大学 一种微米级单晶镍锰酸锂正极材料的制备方法
CN111599999A (zh) * 2020-05-25 2020-08-28 蜂巢能源科技有限公司 无钴正极材料、其制备方法及锂离子电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
XIAO JIN, ZENG LEI-YING CHEN ZHAO-YONG ZHAO HAO PENG ZHONG-DONG: "Synthesis of LiNi0.5Mn0.5O2 as Cathode Material for Lithium Rechargeable Cells", CHINESE JOURNAL OF INORGANIC CHEMISTRY / WU JI HUA XUE XUE BAO, CHINESE ELECTRONIC PERIODICAL SERVICES, CN, vol. 22, no. 4, 30 April 2006 (2006-04-30), CN , pages 685 - 690, XP055873283, ISSN: 1001-4861 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114975983A (zh) * 2022-05-06 2022-08-30 四川新锂想能源科技有限责任公司 高镍低钴材料及其制备方法、电池正极
CN114975981A (zh) * 2022-05-25 2022-08-30 泾河新城陕煤技术研究院新能源材料有限公司 一种镍基无钴正极材料及其制备方法
CN114975981B (zh) * 2022-05-25 2023-12-19 泾河新城陕煤技术研究院新能源材料有限公司 一种镍基无钴正极材料及其制备方法
CN117558904A (zh) * 2024-01-11 2024-02-13 河南科隆新能源股份有限公司 一种多孔核壳结构无钴正极材料及其制备方法

Also Published As

Publication number Publication date
CN111599999A (zh) 2020-08-28
EP3975292A1 (en) 2022-03-30
EP3975292A4 (en) 2022-10-12
JP2022550265A (ja) 2022-12-01
CN111599999B (zh) 2022-04-08
US20240055577A1 (en) 2024-02-15
JP7369277B2 (ja) 2023-10-25
KR20220035191A (ko) 2022-03-21

Similar Documents

Publication Publication Date Title
WO2021238051A1 (zh) 无钴正极材料、其制备方法及锂离子电池
CN111592052B (zh) 镍锰酸锂复合材料、其制备方法及锂离子电池
WO2022000889A1 (zh) 正极材料、其制备方法及锂离子电池
KR102026918B1 (ko) 이차전지용 양극활물질의 제조방법 및 이에 따라 제조된 이차전지용 양극활물질
WO2022199399A1 (zh) 三元正极材料及其制备方法和锂离子电池
CN106663793B (zh) 正极活性材料及其制备方法
KR101624805B1 (ko) 고체 전해질층을 포함하는 이차전지
WO2022011939A1 (zh) 无钴正极材料及其制备方法以及锂离子电池正极和锂电池
WO2021189997A1 (zh) 正极材料及其制备方法，正极、锂离子电池和车辆
JP2019021627A (ja) リチウムイオン電池正極材料及びリチウムイオン電池
WO2022062320A1 (zh) 一种含有金属元素梯度掺杂的负极材料及其应用
WO2022206910A1 (zh) 无钴高镍正极材料、其制备方法及应用
CN102569807A (zh) 一种包覆改性的锰酸锂正极材料及其制备方法
CN108400321B (zh) 一种镍钴铁酸锂正极材料及其制备方法
WO2022062321A1 (zh) 一种硅基负极复合材料和锂二次电池
CN110649230A (zh) 一种纳米铆钉核壳结构正极材料及制备方法
CN113764638A (zh) 正极材料、其制备方法、包括其的正极和锂离子电池
KR101470090B1 (ko) 리튬이차전지용 양극 활물질 복합체, 이의 제조방법 및 이를 이용한 리튬이차전지
CN108682847B (zh) 一种多壳层中空微球形α-Fe2O3材料、制备方法及其应用
KR102617672B1 (ko) 보호막이 코팅된 리튬 전극 및 이를 포함하는 리튬 이차전지
CN114275828B (zh) 富镍材料及其制备方法、正极片、电池及用电设备
CN112614990A (zh) 一种镍锰二元复合正极材料及其制备方法
CN114583150B (zh) 正极活性材料及其应用
CN117247056A (zh) 一种锂离子电池无钴正极材料的制备及其应用
WO2021243928A1 (zh) 一种用于锂离子电池的正极材料及其制备方法和锂离子电池

Legal Events

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

Ref document number: 20937309

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2020937309

Country of ref document: EP

Effective date: 20211221

ENP Entry into the national phase

Ref document number: 20227005073

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2022514560

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 17763664

Country of ref document: US

NENP Non-entry into the national phase

Ref country code: DE