WO2021143374A1 - 无钴层状正极材料及其制备方法、正极片和锂离子电池 - Google Patents

无钴层状正极材料及其制备方法、正极片和锂离子电池 Download PDF

Info

Publication number
WO2021143374A1
WO2021143374A1 PCT/CN2020/132906 CN2020132906W WO2021143374A1 WO 2021143374 A1 WO2021143374 A1 WO 2021143374A1 CN 2020132906 W CN2020132906 W CN 2020132906W WO 2021143374 A1 WO2021143374 A1 WO 2021143374A1
Authority
WO
WIPO (PCT)
Prior art keywords
cobalt
lithium ion
lithium
positive electrode
charge
Prior art date
Application number
PCT/CN2020/132906
Other languages
English (en)
French (fr)
Inventor
乔齐齐
江卫军
许鑫培
施泽涛
马加力
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 EP20913588.8A priority Critical patent/EP3998659A4/en
Priority to US17/764,551 priority patent/US20220340446A1/en
Priority to KR1020217028403A priority patent/KR20210134658A/ko
Priority to JP2022509609A priority patent/JP7326588B2/ja
Publication of WO2021143374A1 publication Critical patent/WO2021143374A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G53/00—Compounds of nickel
    • C01G53/40—Nickelates
    • C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
    • C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
    • C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/04—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
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
    • H01M4/139—Processes of manufacture
    • H01M4/1391—Processes of manufacture of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/362—Composites
    • H01M4/366—Composites as layered products
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • 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
    • C01P2004/00—Particle morphology
    • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00—Particle morphology
    • C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
    • C01P2004/82—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
    • C01P2004/84—Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00—Physical properties of inorganic compounds
    • C01P2006/12—Surface area
    • 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
    • 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
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0068—Solid electrolytes inorganic
    • H01M2300/0071—Oxides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention relates to the technical field of lithium ion batteries, in particular to a cobalt-free layered positive electrode material and a preparation method thereof, a positive electrode sheet and a lithium ion battery.
  • the positive electrode active material plays a vital role.
  • the related art cathode active materials ternary cathode active materials are widely used due to their higher capacity, voltage, and cycle stability.
  • the ternary positive electrode active material contains a certain amount of cobalt, which causes its price to be higher. Therefore, only reducing the cobalt content in the ternary positive electrode active material can better reduce the cost of the positive electrode active material.
  • the cost is the lowest, that is, the cobalt-free layer Shaped cathode material.
  • the cobalt-free layered cathode material in the related art does not contain cobalt, its conductivity is poor, and the diffusion rate of lithium ions in the cobalt-free layered cathode material is also slow.
  • an object of the present invention is to provide a lithium ion battery with low cost, low surface impedance, good conductivity, fast diffusion of lithium ions in it, high electrochemical activity, and high specific charge capacity of lithium ion batteries made therefrom. , High discharge specific capacity, high first efficiency, good cycle performance or cobalt-free layered cathode material with good rate performance.
  • the present invention provides a cobalt-free layered cathode material for lithium ion batteries.
  • the cobalt-free layered cathode material includes: LiNi 0.75 Mn 0.25 O 2 crystal; and a lithium ion conductor attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal
  • the lithium ion conductor includes at least one of lithium titanate or lithium manganate.
  • the mass percentage of the lithium ion conductor is 0.1% to 2%, wherein said cobalt-free layered cathode material specific surface area of 0.1m 2 /g ⁇ 0.8m 2 / g, the layered cathode material is cobalt-free D 50 particle size of 1 ⁇ m ⁇ 10 ⁇ m.
  • the lithium ion diffusion rate in the cobalt-free layered cathode material is fast and the electrochemical activity is high.
  • the lithium ion produced therefrom The battery has a high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance.
  • the present invention provides a cobalt-free layered cathode material for lithium ion batteries.
  • the inventor found that the cobalt-free layered cathode material has low cost, low surface impedance, and good conductivity.
  • the lithium ion diffusion rate in the cobalt-free layered cathode material is fast and the electrochemical activity is high.
  • the lithium ion produced therefrom The battery has a high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance.
  • the lithium ion conductor includes at least one of lithium titanate or lithium manganate.
  • the lithium ion conductor is lithium titanate, and based on the total mass of the cobalt-free layered positive electrode material, the mass percentage of the lithium titanate is 0.1% to 1%.
  • the lithium ion conductor is lithium manganate, and based on the total mass of the cobalt-free layered positive electrode material, the mass percentage of the lithium manganate is 0.1% to 2%.
  • the cobalt-free layered cathode material satisfies at least one of the following conditions: a specific surface area of 0.1m 2 /g ⁇ 0.8m 2 / g; D 50 particle size of 1 ⁇ m ⁇ 10 ⁇ m; the x Is 0.75, and the y is 0.25.
  • the present invention provides a method for preparing the aforementioned cobalt-free layered cathode material.
  • the method includes: providing LiNi x Mn y O 2 crystals; mixing the LiNi x Mn y O 2 crystals and materials forming the lithium ion conductor to obtain a first mixture; Under the condition of 800° C., the first mixture is subjected to a first calcination treatment for 5 hours to 10 hours in an atmosphere containing oxygen, so as to obtain the cobalt-free layered positive electrode material.
  • the inventor found that the method is simple, convenient, easy to implement, easy to industrialize, and can effectively prepare the aforementioned cobalt-free layered cathode material.
  • the material forming the lithium ion conductor includes: a first lithium source; and at least one of a titanium source or a first manganese source.
  • the titanium source includes at least one of tetrabutyl titanate or titanium oxide.
  • the first manganese source includes at least one of manganese carbonate, manganese acetate or manganese oxide.
  • the LiNi x Mn y O 2 crystal is provided through the following steps: mixing a second lithium source, a nickel source, and a second manganese source to obtain a second mixture; Next, the second mixture is subjected to a second calcination treatment for 10 hours to 15 hours in an atmosphere containing oxygen to obtain the LiNi x Mn y O 2 crystals.
  • the first lithium source and the second lithium source each independently include at least one of LiOH, Li 2 CO 3 , CH 3 COOLi, or LiNO 3.
  • the nickel source and the second manganese source each independently include Ni a Mn b (OH) 2 , wherein 0.55 ⁇ a ⁇ 0.95 and 0.05 ⁇ b ⁇ 0.45.
  • the present invention provides a positive electrode sheet.
  • the positive electrode sheet includes the aforementioned cobalt-free layered positive electrode material.
  • the present invention provides a lithium ion battery.
  • the lithium ion battery includes: a negative electrode; a positive electrode, the positive electrode including the aforementioned cobalt-free layered positive electrode material or the aforementioned positive electrode sheet; a battery separator; and an electrolyte.
  • the inventor found that the lithium ion battery has high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance, and the lithium ion battery has the aforementioned cobalt-free layered cathode material or the aforementioned All the features and advantages of the positive electrode sheet mentioned above will not be repeated here.
  • the lithium ion battery satisfies at least one of the following conditions: under the condition of 0.1C charge and discharge rate, the first charge specific capacity is not less than 205.1mAh/g; under the condition of 0.1C charge and discharge rate The first discharge specific capacity is not less than 181.9mAh/g; the first charge-discharge efficiency is not less than 88.7% under the condition of 0.1C charge-discharge rate; under the condition of 1C charge-discharge rate, the lithium-ion battery is After 50 cycles of charge and discharge, the capacity retention rate is not less than 98.3%; under the condition of 0.5C charge and discharge rate, the first discharge specific capacity is not less than 170.2mAh/g; under the condition of 1C charge and discharge rate, the first discharge The specific capacity is not less than 164.8mAh/g; under the condition of 2C charge and discharge rate, the first discharge specific capacity is not less than 155.7mAh/g; under the condition of 3C charge and discharge rate, the first discharge specific capacity is not less than 149.
  • Fig. 1 shows a schematic flow chart of a method for preparing a cobalt-free layered cathode material according to an embodiment of the present invention.
  • Figure 2 shows a schematic flow diagram of the steps of providing LiNi x Mn y O 2 crystals in an embodiment of the present invention.
  • Fig. 3 shows scanning electron micrographs of LiNi x Mn y O 2 crystals in Example 1 and Example 2 of the present invention (the scale bar in the figure a is 2 ⁇ m; the scale bar in the figure b is 200 nm).
  • Fig. 4 shows a scanning electron microscope photograph of the cobalt-free layered cathode material in Example 1 of the present invention (the scale bar in the figure a is 2 ⁇ m; the scale bar in the figure b is 200 nm).
  • Fig. 5 shows a scanning electron microscope photograph of the cobalt-free layered cathode material in Example 2 of the present invention (the scale bar in the figure a is 2 ⁇ m; the scale bar in the figure b is 200 nm).
  • Figure 6 shows the first charge and discharge curves of the lithium ion batteries in Example 1, Example 2 and Comparative Example 1 of the present invention
  • line a is the first charge and discharge curve of the lithium ion battery in Example 1
  • line b is an example The first charge-discharge curve of the lithium-ion battery in 2
  • line c is the first charge-discharge curve of the lithium-ion battery in Comparative Example 1).
  • FIG. 7 shows the cycle performance test results of the lithium ion batteries in Example 1, Example 2 and Comparative Example 1 of the present invention.
  • the present invention provides a cobalt-free layered cathode material for lithium ion batteries.
  • the cobalt-free layered cathode material includes: LiNi 0.75 Mn 0.25 O 2 crystal; and a lithium ion conductor attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal
  • the lithium ion conductor includes at least one of lithium titanate or lithium manganate.
  • the mass percentage of the lithium ion conductor is 0.1% to 2%, wherein said cobalt-free layered cathode material specific surface area of 0.1m 2 /g ⁇ 0.8m 2 / g, the layered cathode material is cobalt-free D 50 particle size of 1 ⁇ m ⁇ 10 ⁇ m.
  • the lithium ion diffusion rate in the cobalt-free layered cathode material is fast and the electrochemical activity is high.
  • the lithium ion produced therefrom The battery has a high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance.
  • the present invention provides a cobalt-free layered cathode material for lithium ion batteries.
  • the inventor found that the cobalt-free layered cathode material has low cost, low surface impedance, and good conductivity.
  • the lithium ion diffusion rate in the cobalt-free layered cathode material is fast and the electrochemical activity is high.
  • the lithium ion produced therefrom The battery has a high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance.
  • the x may be specifically 0.75; correspondingly, the y may be specifically 0.25.
  • the chemical formula of the LiNi x Mn y O 2 crystal is LiNi 0.75 Mn 0.25 O 2 .
  • the mass percentage of the LiNi x Mn y O 2 crystal may be 98%-99.5 percent. Specifically, in some embodiments of the present invention, the mass percentage of the LiNi x Mn y O 2 crystal may specifically be 99.3%.
  • the mass percentage of the LiNi x Mn y O 2 crystal is within the above range, so that the cobalt-free layered cathode material has higher electrochemical activity and is suitable for use in lithium ion batteries.
  • the inventor has conducted in-depth investigations and a large number of experimental verifications on the specific types of lithium ion conductors and found that the specific types of lithium ion conductors may include lithium titanate or lithium manganate, etc. .
  • the lithium ion conductor is lithium titanate or lithium manganate
  • the cobalt-free layered cathode material has lower surface impedance, better conductivity, and higher electrochemical activity.
  • the lithium ion conductor may be lithium titanate, and based on the total mass of the cobalt-free layered cathode material, the mass percentage of the lithium titanate is 0.1% to 1. %. Specifically, in some embodiments of the present invention, the mass percentage of the lithium titanate may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% Or 1% etc. Therefore, the mass percentage of lithium titanate in the cobalt-free layered cathode material is within the above range, which will not cause the conductivity of the cobalt-free layered cathode material to be relatively low due to the low content of lithium titanate. Poor; it will not slow down the diffusion rate of lithium ions in the cobalt-free layered cathode material due to the excessive content of lithium titanate.
  • the lithium ion conductor may also be lithium manganate.
  • the mass percentage of the lithium manganate is 0.1% to 2%. .
  • the mass percentage of the lithium manganate may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%. , 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9% or 2% etc.
  • the mass percentage content of lithium manganate in the cobalt-free layered cathode material is within the above range, which will not cause the conductive performance of the cobalt-free layered cathode material to be relatively low due to the low content of lithium manganate. Poor; it will not slow down the diffusion rate of lithium ions in the cobalt-free layered cathode material due to the excessive content of lithium manganate.
  • the specific surface area of the cobalt-free layered cathode material may be 0.1m 2 /g,0.2m 2 /g,0.3m 2 /g,0.4m 2 /g,0.5 m 2 /g,0.6m 2 /g,0.7m 2 / g or 0.8m 2 / g and the like, cobalt-free layered cathode material having a specific surface area within the above range, the positive electrode may be such that lithium ions in the cobalt-free layer The diffusion rate in the material is faster and the electrochemical activity is higher.
  • the D 50 particle size of the cobalt-free layered cathode material may be 1 ⁇ m-10 ⁇ m.
  • the particle size of the cobalt-free layered cathode material may be 1 ⁇ m, 2 ⁇ m, 3 ⁇ m, 4 ⁇ m, 5 ⁇ m, 6 ⁇ m, 7 ⁇ m, 8 ⁇ m, 9 ⁇ m, or 10 ⁇ m.
  • the inventors have found that, when the D 50 particle size of the cobalt-free cathode material layered within the above range, better electrochemical activity, thus making its performance aspects of the lithium ion battery was produced in the better.
  • the cobalt-free layered cathode material is alkaline. In some embodiments of the present invention, 11 ⁇ pH ⁇ 12 of the cobalt-free layered cathode material. Therefore, the cobalt-free layered positive electrode material is more suitable for use in the positive electrode of a lithium ion battery.
  • the impurities may be the residues of the cobalt-free layered cathode material during the preparation process.
  • the present invention provides a method for preparing the aforementioned cobalt-free layered cathode material. According to an embodiment of the present invention, referring to FIG. 1, the method includes the following steps:
  • the LiNi x Mn y O 2 crystal is provided through the following steps:
  • the second lithium source may include LiOH, Li 2 CO 3 , CH 3 COOLi, LiNO 3 , or the like.
  • the material source is wide, easy to obtain, and the cost is low, and the lithium source can be better provided to form LiNi x Mn y O 2 crystals.
  • the nickel source may include Ni a Mn b (OH) 2 , where 0.55 ⁇ a ⁇ 0.95 and 0.05 ⁇ b ⁇ 0.45.
  • the a may be 0.55, 0.65, 0.75, 0.85, or 0.95, etc.
  • the b may be 0.05, 0.15, 0.25, 0.35, or 0.45, etc. Therefore, the material source is wide, easy to obtain, and the cost is low, and the nickel source can be better provided to form LiNi x Mn y O 2 crystals.
  • the second manganese source may include Ni a Mn b (OH) 2 , where 0.55 ⁇ a ⁇ 0.95 and 0.05 ⁇ b ⁇ 0.45.
  • the a may be 0.55, 0.65, 0.75, 0.85, or 0.95, etc.
  • the b may be 0.05, 0.15, 0.25, 0.35, or 0.45, etc. Therefore, the material source is wide, easy to obtain, and the cost is low, and the manganese source can be better provided to form LiNi x Mn y O 2 crystals.
  • the nickel source and the second manganese source are both Ni a Mn b (OH) 2
  • the nickel source and the second manganese source may be At the same time, it is added to the above system to obtain the second mixture. Therefore, the operation is simple, convenient, easy to realize, and easy to industrialized production.
  • a high-speed mixing device may be used for mixing.
  • the rotation speed of the high-speed mixing device may be 800 rpm/min to 900 rpm/min, and specifically may be 800 rpm/min. min, 820rpm/min, 840rpm/min, 860rpm/min, 880rpm/min, 900rpm/min, etc.; the mixing time may be 5min-20min, specifically may be 5min, 10min, 15min or 20min. Therefore, the mixing effect is better.
  • the temperature of the above-mentioned second firing treatment may specifically be 750°C, 800°C, 850°C, 900°C, 950°C, 1000°C, and the like. Therefore, the above-mentioned temperature range is a relatively suitable temperature range, and the calcination treatment can be better performed, thereby effectively preparing LiNi x Mn y O 2 crystals.
  • the time of the above-mentioned second roasting treatment may specifically be 10h, 11h, 12h, 13h, 14h, 15h, or the like. Therefore, the above-mentioned time range is a more suitable time range, and the calcination treatment can be better performed, thereby effectively preparing LiNi x Mn y O 2 crystals.
  • the volume fraction of oxygen is greater than 90%, specifically, it can be 91%, 92%, 93%, 94%, 95%, 96%. , 97%, 98% or 99%, etc.
  • the firing treatment can be better performed, so that LiNi x Mn y O 2 crystals can be effectively prepared.
  • the crushing treatment may include the conventional crushing treatment in the related art.
  • it can be roller crushing, mechanical crushing or jet crushing;
  • the sieving treatment can be through a 300-400 mesh screen to remove impurities with larger particle size. The specific process will not be repeated here. Too much detail.
  • the material forming the lithium ion conductor includes: a first lithium source; and at least one of a titanium source or a first manganese source.
  • the titanium source when the prepared lithium ion conductor is lithium titanate, the titanium source may specifically include tetrabutyl titanate or titanium oxide; in other embodiments of the present invention, when the prepared lithium ion conductor When the lithium ion conductor of is lithium manganate, the first manganese source may specifically include manganese carbonate, manganese acetate, or manganese oxide.
  • the first lithium source may include LiOH, Li 2 CO 3 , CH 3 COOLi, LiNO 3 , or the like. Therefore, the material source is wide, easy to obtain, and the cost is low, and the aforementioned cobalt-free layered cathode material can be effectively prepared.
  • the LiNi x Mn y O 2 crystal and the material forming the lithium ion conductor are mixed, the LiNi x Mn y O 2 crystal, the first lithium source and the titanium source or the second
  • the molar ratio between one manganese source can be (4 ⁇ 1):1. Specifically, it can be 3:1, 2:1. Therefore, the above-mentioned feed ratio can effectively prepare the cobalt-free layered cathode material with better performance as described above, which will not cause the conductive performance of the cobalt-free layered cathode material to be lower due to the lower content of the lithium ion conductor. Poor; it will not slow down the diffusion rate of lithium ions in the cobalt-free layered cathode material due to the excessive content of the lithium ion conductor.
  • the temperature of the above-mentioned first firing treatment may specifically be 600°C, 650°C, 700°C, 750°C, or 800°C. Therefore, the above-mentioned temperature range is a relatively suitable temperature range, and the firing treatment can be better performed, so as to effectively prepare the cobalt-free layered cathode material.
  • the time of the above-mentioned first roasting treatment may specifically be 5h, 6h, 7h, 8h, 9h or 10h. Therefore, the above-mentioned time range is a relatively suitable time range, and the baking treatment can be better performed, so as to effectively prepare the cobalt-free layered cathode material.
  • the volume fraction of oxygen is greater than 90%, specifically, it can be 91%, 92%, 93%, 94%, 95%, 96%. , 97%, 98% or 99%, etc.
  • the firing treatment can be better performed, so that the cobalt-free layered positive electrode material can be effectively prepared.
  • the cobalt-free layered positive electrode material after obtaining the cobalt-free layered positive electrode material, it can also be subjected to sieving treatment.
  • the sieving treatment can be a sieve of 300 mesh to 400 mesh. The specific process of removing impurities with larger particle size will not be repeated here.
  • the present invention provides a positive electrode sheet.
  • the positive electrode sheet includes the aforementioned cobalt-free layered positive electrode material.
  • the positive electrode sheet may also include other components of a conventional positive electrode sheet, such as a substrate, a conductive agent, and a binder. As well as thickeners, etc., I won't repeat them here.
  • the negative electrode, battery separator, electrolyte, etc. can all be common types in the field.
  • the battery separator can be a polypropylene microporous membrane (Celgard 2400)
  • the electrolyte composition can be LiPF 6 (lithium hexafluorophosphate)/EC (Ethylene carbonate)-DMC (Dimethyl carbonate)).
  • the present invention provides a lithium ion battery.
  • the lithium ion battery includes: a negative electrode; a positive electrode, the positive electrode including the aforementioned cobalt-free layered positive electrode material or the aforementioned positive electrode sheet; a battery separator; and an electrolyte.
  • the inventor found that the lithium ion battery has high charge specific capacity, high discharge specific capacity, high first efficiency, good cycle performance, and good rate performance, and the lithium ion battery has the aforementioned cobalt-free layered cathode material or the aforementioned All the features and advantages of the positive electrode sheet mentioned above will not be repeated here.
  • the first charging specific capacity of the lithium ion battery is not less than 205.1 mAh/g under the condition of a charge-discharge rate of 0.1C. As a result, the specific charge capacity of the lithium ion battery is high.
  • the first discharge specific capacity of the lithium ion battery under the condition of 0.1C charge and discharge rate is not less than 181.9 mAh/g.
  • the specific discharge capacity of the lithium ion battery is high.
  • the first charge-discharge efficiency of the lithium-ion battery under the condition of a charge-discharge rate of 0.1C is not less than 88.7%. As a result, the first efficiency of the lithium ion battery is high.
  • the lithium-ion battery has a capacity retention rate of not less than 98.3% after 50 charge-discharge cycles under the condition of a 1C charge-discharge rate. As a result, the cycle performance of the lithium ion battery is good.
  • the first discharge specific capacity of the lithium-ion battery is not less than 170.2mAh/g under the condition of 0.5C charge-discharge rate; under the condition of 1C charge-discharge rate, the first discharge specific capacity is not less than 164.8mAh/g; under the condition of 2C charge-discharge rate, the first discharge specific capacity is not less than 155.7mAh/g; under the condition of 3C charge-discharge rate, the first discharge specific capacity is not less than 149.7mAh/g; charge at 4C Under the condition of discharge rate, the first discharge specific capacity is not less than 145.1mAh/g. Therefore, the rate performance of the lithium ion battery is good.
  • the shape, structure, and manufacturing process of the other structures and components of the lithium ion battery can be conventional shapes, structures, and manufacturing processes, which will not be repeated here. .
  • the cobalt-free layered cathode material includes:
  • LiNi 0.75 Mn 0.25 O 2 crystal see Figure 3 for scanning electron microscopy photos
  • a lithium ion conductor attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal, and the lithium ion conductor is titanium Lithium oxide, based on the total mass of the cobalt-free layered cathode material, the mass percentage of the lithium titanate is 0.2%, the specific surface area of the cobalt-free layered cathode material is 0.7m 2 /g, The particle size of the cobalt-free layered cathode material is 3 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.40g LiOH and 100g precursor Ni 0.75 Mn 0.25 (OH) 2 for 10 minutes and rotate at 800rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at a temperature of 930°C, and the reaction time was 10 hours. After the reaction, the temperature was naturally cooled and passed through a 400 mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • Step 2 The lithium nickel manganese oxide (100g) obtained in step 1 is uniformly mixed with 0.07g LiOH and 0.17g TiO 2 in a high-speed mixer to obtain a premix; then the premix is reacted at 700°C for 5 hours, wherein the reaction atmosphere The oxygen concentration is 90%. After the reaction, the temperature is naturally cooled and passed through a 400 mesh screen to obtain a cobalt-free layered cathode material, wherein the mass content of lithium titanate in the cobalt-free layered cathode material is 0.2%.
  • FIG. 4 for the scanning electron micrograph of the cobalt-free layered cathode material. It can be seen from FIGS. 3 and 4 that at least part of the surface of the cobalt-free layered cathode material is attached with lithium titanate; while the surface of the LiNi 0.75 Mn 0.25 O 2 crystal is relatively smooth, and no other materials are attached.
  • the cobalt-free layered positive electrode material is homogenized and coated to make a positive electrode sheet, and then assembled into a lithium-ion battery.
  • the negative electrode uses metal lithium sheet;
  • the battery separator uses Celgard 2400 microporous polypropylene membrane;
  • the electrolyte uses LiPF 6 (lithium hexafluorophosphate). )/EC (Ethylene Carbonate)-DMC (Dimethyl Carbonate), battery model R2032, the same below.
  • the cobalt-free layered cathode material includes:
  • LiNi 0.75 Mn 0.25 O 2 crystal see Figure 3 for scanning electron microscopy photos
  • a lithium ion conductor attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal, and the lithium ion conductor is manganese Lithium oxide, based on the total mass of the cobalt-free layered cathode material, the mass percentage of the lithium manganate is 0.15%, the specific surface area of the cobalt-free layered cathode material is 0.70 m 2 /g, The particle size of the cobalt-free layered cathode material is 3 ⁇ m.
  • Step 2 The lithium nickel manganate (100g) obtained in step 1 is uniformly mixed with 0.035g LiOH and 0.14g MnO 2 in a high-speed mixer to obtain a premix; then the premix is reacted at 700°C for 5 hours, wherein the reaction atmosphere The concentration of oxygen in the oxygen is 90%. After the reaction, the temperature is naturally cooled and passed through a 400 mesh screen to obtain a cobalt-free layered cathode material, wherein the mass content of lithium titanate in the cobalt-free layered cathode material is 0.15%.
  • FIG. 5 for the scanning electron micrograph of the cobalt-free layered cathode material. It can be seen from FIGS. 3 and 5 that lithium manganate is attached to at least part of the surface of the cobalt-free layered cathode material; while the surface of the LiNi 0.75 Mn 0.25 O 2 crystal is relatively smooth, and no other materials are attached.
  • a lithium ion battery was obtained in the same manner as in Example 1.
  • LiNi 0.75 Mn 0.25 O 2 crystal and a lithium ion conductor the lithium ion conductor is attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal, the lithium ion conductor is lithium titanate, based on the cobalt-free layer
  • the total mass of the positive electrode material, the mass percentage of the lithium titanate is 0.1%, the specific surface area of the cobalt-free layered positive electrode material is 0.1 m 2 /g, and the particle size of the cobalt-free layered positive electrode material It is 10 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.40g LiOH and 100g precursor Ni 0.75 Mn 0.25 (OH) 2 for 10 minutes and rotate at 800 rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at 1000°C and the reaction time was 15h. After the reaction, the temperature was naturally lowered and passed through a 400 mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • Step 2 The lithium nickel manganate (100g) obtained in step 1 is uniformly mixed with 0.035g LiOH and 0.085g TiO 2 in a high-speed mixer to obtain a premix; then the premix is reacted at 700°C for 5 hours, wherein the reaction atmosphere The oxygen concentration in the oxygen is 90%. After the reaction, the temperature is naturally lowered and passed through a 400 mesh screen to obtain a cobalt-free layered cathode material, wherein the mass content of lithium titanate in the cobalt-free layered cathode material is 0.1%.
  • LiNi 0.75 Mn 0.25 O 2 crystal and a lithium ion conductor the lithium ion conductor is attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal, the lithium ion conductor is lithium titanate, based on the cobalt-free layer
  • the total mass of the positive electrode material, the mass percentage of the lithium titanate is 2.0%, the specific surface area of the cobalt-free layered positive electrode material is 0.8 m 2 /g, and the particle size of the cobalt-free layered positive electrode material It is 1 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.40g LiOH and 100g precursor Ni 0.75 Mn 0.25 (OH) 2 for 10 minutes and rotate at 800rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at a temperature of 880°C, and the reaction time was 20 hours. After the reaction, the temperature was naturally cooled and passed through a 400 mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • Step 2 The lithium nickel manganese oxide (100g) obtained in step 1 is uniformly mixed with 0.7g LiOH and 1.7g TiO 2 in a high-speed mixer to obtain a premix; then the premix is reacted at 700°C for 5 hours, wherein the reaction atmosphere The oxygen concentration in the oxygen is 90%. After the reaction, the temperature is naturally cooled and passed through a 400-mesh screen to obtain a cobalt-free layered cathode material, wherein the mass content of lithium titanate in the cobalt-free layered cathode material is 2.0%
  • LiNi 0.75 Mn 0.25 O 2 crystal and a lithium ion conductor the lithium ion conductor is attached to at least part of the surface of the LiNi 0.75 Mn 0.25 O 2 crystal, the lithium ion conductor is lithium titanate, based on the cobalt-free layer
  • the total mass of the positive electrode material, the mass percentage of the lithium titanate is 3.0%, the specific surface area of the cobalt-free layered positive electrode material is 1.0 m 2 /g, and the particle size of the cobalt-free layered positive electrode material It is 0.5 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.40g LiOH and 100g precursor Ni 0.75 Mn 0.25 (OH) 2 for 10 minutes and rotate at 800rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at a temperature of 850°C, and the reaction time was 10 hours. After the reaction, the temperature was naturally cooled and passed through a 400 mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • Step 2 The lithium nickel manganese oxide (100g) obtained in step 1 is uniformly mixed with 1.05g LiOH and 2.55g TiO 2 in a high-speed mixer to obtain a premix; then the premix is reacted at 700°C for 5 hours, wherein the reaction atmosphere The oxygen concentration in the oxygen is 90%. After the reaction, the temperature is naturally cooled and passed through a 400 mesh screen to obtain a cobalt-free layered cathode material. The mass content of lithium titanate in the cobalt-free layered cathode material is 3.0%
  • LiNi 0.55 Mn 0.45 O 2 crystal LiNi 0.55 Mn 0.45 O 2 crystal; and a lithium ion conductor attached to at least part of the surface of the LiNi 0.55 Mn 0.45 O 2 crystal, and the lithium ion conductor is lithium titanate based on the cobalt-free
  • the total mass of the layered cathode material, the mass percentage of the lithium titanate is 0.2%, the specific surface area of the cobalt-free layered cathode material is 0.7 m 2 /g, and the particles of the cobalt-free layered cathode material The diameter is 3 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.0g LiOH and 100g precursor Ni 0.55 Mn 0.45 (OH) 2 for 10 minutes and rotate at 800rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at a temperature of 980°C, and the reaction time was 10 hours. After the reaction, the temperature was naturally cooled and passed through a 400 mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • LiNi 0.95 Mn 0.05 O 2 crystal LiNi 0.95 Mn 0.05 O 2 crystal; and a lithium ion conductor attached to at least part of the surface of the LiNi 0.95 Mn 0.05 O 2 crystal, and the lithium ion conductor is lithium titanate based on the cobalt-free
  • the total mass of the layered cathode material, the mass percentage of the lithium titanate is 0.2%, the specific surface area of the cobalt-free layered cathode material is 0.7m 2 /g, and the particles of the cobalt-free layered cathode material The diameter is 3 ⁇ m.
  • Step 1 Use high-speed mixing equipment to mix 47.80g LiOH and 100g precursor Ni 0.95 Mn 0.05 (OH) 2 for 10 minutes and rotate at 800rpm; put the mixed materials in an oxygen atmosphere (concentration greater than or equal to 90%) The reaction was carried out at 800°C and the reaction time was 10h. After the reaction, the temperature was naturally cooled and passed through a 400-mesh screen to obtain a layered lithium nickel manganate with a single crystal morphology;
  • the cobalt-free layered cathode material package is: LiNi 0.55 Mn 0.45 O 2 crystals.
  • the specific surface area of the cobalt-free layered cathode material is 0.7 m 2 /g, and the particle size of the cobalt-free layered cathode material is 3 ⁇ m.
  • the first charge and discharge specific capacity of the lithium ion battery in Comparative Example 1 is 200.7mAh/g and 172.5mAh/g under the condition of 0.1C charge and discharge rate, and the first efficiency is 85.9%;
  • Example 1 Under the condition of 0.1C charge and discharge rate, the first charge and discharge specific capacity is 205.1 and 181.9mAh/g, and the first efficiency is 88.7%;
  • the lithium ion battery in Example 2 is at 0.1C charge and discharge rate. Under these conditions, the first charge and discharge specific capacities are 209.1mAh/g and 185.7mAh/g, and the first efficiency is 88.9%. Therefore, the lithium ion battery produced by the cobalt-free layered positive electrode material of the present invention has a high charge specific capacity, a high discharge specific capacity, and a high first-time efficiency.
  • the lithium-ion battery in Comparative Example 1 was charged and discharged at 1C and after 50 cycles of charge and discharge, the capacity retention rate was only 96.9%; the lithium-ion battery in Example 1 was charged and discharged at 1C Under the condition of rate, after 50 cycles of charge and discharge, the capacity retention rate is 99.2%; for the lithium ion battery in Example 2 under the condition of 1C charge and discharge rate, after 50 cycles of charge and discharge, the capacity retention rate is 98.3 %. Under the condition of 1C charge-discharge rate, the lithium-ion battery in Example 2 has a capacity retention rate of 98.3% after 50 cycles of charge and discharge. The lithium-ion battery in Example 3 has a 1C charge-discharge rate.
  • the capacity retention rate is 97.6%; in Example 4, the lithium-ion battery in Example 4 is charged and discharged at a rate of 1C, and after 50 cycles of charge and discharge, the capacity retention rate is 98.9%; in Example 5 Under the condition of 1C charge-discharge rate, the capacity retention rate of the lithium-ion battery is 96.3% after 50 cycles of charge and discharge; the lithium-ion battery in Example 6 undergoes 50 charge-discharge cycles under the condition of 1C charge-discharge rate After 50 cycles, the capacity retention rate of the lithium-ion battery in Example 7 was 95.1% under the condition of 1C charge-discharge rate. Therefore, the cobalt-free layered cathode material of the present invention has good cycle performance.
  • first and second are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined with “first” and “second” may explicitly or implicitly include one or more of these features.
  • “plurality” means two or more than two, unless otherwise specifically defined.

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)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Inorganic Compounds Of Heavy Metals (AREA)
  • Secondary Cells (AREA)

Abstract

本发明提供了无钴层状正极材料及其制备方法、正极片和锂离子电池。该无钴层状正极材料包括：LiNi xMn yO 2晶体，其中，x+y＝1，0.55≤x≤0.95，0.05≤y≤0.45；和锂离子导体，所述锂离子导体附着在所述LiNi xMn yO 2晶体的至少部分表面上。该无钴层状正极材料成本低、表面阻抗低、导电性好，锂离子在该无钴层状正极材料中的扩散速度快，电化学活性高，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好。

Description

无钴层状正极材料及其制备方法、正极片和锂离子电池 技术领域
本发明涉及锂离子电池技术领域，具体地，涉及无钴层状正极材料及其制备方法、正极片和锂离子电池。
背景技术
目前，随着新能源汽车行业的快速发展，人类对锂离子电池的要求越来越高。在锂离子电池的四大主材中，正极活性材料发挥着至关重要的作用。在相关技术的正极活性材料中，三元正极活性材料因具有较高的容量、电压、循环稳定性而得到广泛应用。然而，三元正极活性材料中因含有一定量的钴元素而导致其价格较高。因此，只有降低三元正极活性材料中的钴含量才能够较好地降低正极活性材料的成本，其中，当该正极活性材料中完全不含有钴元素时，其成本达到最低，即为无钴层状正极材料。遗憾的是，相关技术中的无钴层状正极材料中由于不含有钴元素，其导电性差，锂离子在该无钴层状正极材料中的扩散速度也慢。
因而，现有的无钴层状正极材料的相关技术仍有待改进。
发明内容
本发明旨在至少在一定程度上解决相关技术中的技术问题之一。为此，本发明的一个目的在于提出一种成本低、表面阻抗低、导电性好、锂离子在其中的扩散速度快、电化学活性高、由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好或者倍率性能好的无钴层状正极材料。
在本发明的一个方面，本发明提供了一种用于锂离子电池的无钴层状正极材料。根据本发明的实施例，该无钴层状正极材料包括：LiNi 0.75Mn 0.25O 2晶体；和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体包括钛酸锂或者锰酸锂中的至少一种，基于所述无钴层状正极材料的总质量，所述锂离子导体的质量百分含量为0.1％～2％，其中，所述无钴层状正极材料的比表面积为0.1m 2/g～0.8m 2/g，所述无钴层状正极材料的D 50粒径为1μm～10μm。发明人发现，该无钴层状正极材料成本低、表面阻抗低、导电性好，锂离子在该无钴层状正极材料中的扩散速度快，电化学活性高，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好。
在本发明的另一个方面，本发明提供了一种用于锂离子电池的无钴层状正极材料。根据本发明的实施例，该无钴层状正极材料包括：LiNi xMn yO 2晶体，其中，x+y＝1，0.55≤x≤0.95，0.05≤y≤0.45；和锂离子导体，所述锂离子导体附着在所述LiNi xMn yO 2晶体的至少部分表面上。发明人发现，该无钴层状正极材料成本低、表面阻抗低、导电性好，锂离子在该无钴层状正 极材料中的扩散速度快，电化学活性高，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好。
根据本发明的实施例，所述锂离子导体包括钛酸锂或者锰酸锂中的至少一种。
根据本发明的实施例，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.1％～1％。
根据本发明的实施例，所述锂离子导体为锰酸锂，基于所述无钴层状正极材料的总质量，所述锰酸锂的质量百分含量为0.1％～2％。
根据本发明的实施例，所述无钴层状正极材料满足以下条件的至少之一：比表面积为0.1m 2/g～0.8m 2/g；D 50粒径为1μm～10μm；所述x为0.75，所述y为0.25。
在本发明的另一个方面，本发明提供了一种制备前面所述的无钴层状正极材料的方法。根据本发明的实施例，该方法包括：提供LiNi xMn yO 2晶体；将所述LiNi xMn yO 2晶体和形成所述锂离子导体的材料混合，得到第一混合物；在600℃～800℃条件下，将所述第一混合物于含有氧气的气氛中进行第一焙烧处理5h～10h，以便得到所述无钴层状正极材料。发明人发现，该方法操作简单、方便，容易实现，易于工业化生产，且可以有效制备得到前面所述的无钴层状正极材料。
根据本发明的实施例，形成所述锂离子导体的材料包括：第一锂源；和钛源或者第一锰源中的至少一种。
根据本发明的实施例，所述钛源包括钛酸四丁酯或者氧化钛中的至少一种。
根据本发明的实施例，所述第一锰源包括碳酸锰、乙酸锰或者氧化锰中的至少一种。
根据本发明的实施例，所述LiNi xMn yO 2晶体是经由下列步骤提供的：将第二锂源、镍源和第二锰源混合，得到第二混合物；在750℃～1000℃条件下，将所述第二混合物于含有氧气的气氛中进行第二焙烧处理10h～15h，得到所述LiNi xMn yO 2晶体。
根据本发明的实施例，所述第一锂源和所述第二锂源各自独立地包括LiOH、Li 2CO 3、CH 3COOLi或者LiNO 3中的至少一种。
根据本发明的实施例，所述镍源和所述第二锰源各自独立地包括Ni aMn b(OH) 2，其中，0.55≤a≤0.95，0.05≤b≤0.45。
在本发明的又一个方面，本发明提供了一种正极片。根据本发明的实施例，该正极片包括前面所述的无钴层状正极材料。发明人发现，该正极片成本低、导电性好，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好，且该正极片具有前面所述的无钴层状正极材料的所有特征和优点，在此不再过多赘述。
在本发明的再一个方面，本发明提供了一种锂离子电池。根据本发明的实施例，该锂离子电池包括：负极；正极，所述正极包括前面所述的无钴层状正极材料或前面所述的正极片； 电池隔膜；和电解液。发明人发现，该锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好，且该锂离子电池具有前面所述的无钴层状正极材料或前面所述的正极片的所有特征和优点，在此不再过多赘述。
根据本发明的实施例，所述锂离子电池满足以下条件的至少之一：在0.1C充放电倍率的条件下，首次充电比容量不低于205.1mAh/g；在0.1C充放电倍率的条件下，首次放电比容量不低于181.9mAh/g；在0.1C充放电倍率的条件下，首次充放电效率不低于88.7％；在1C充放电倍率的条件下，所述锂离子电池在经过50次的充放电循环以后，容量保持率不低于98.3％；在0.5C充放电倍率的条件下，首次放电比容量不低于170.2mAh/g；在1C充放电倍率的条件下，首次放电比容量不低于164.8mAh/g；在2C充放电倍率的条件下，首次放电比容量不低于155.7mAh/g；在3C充放电倍率的条件下，首次放电比容量不低于149.7mAh/g；在4C充放电倍率的条件下，首次放电比容量不低于145.1mAh/g。
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显示了本发明一个实施例的制备无钴层状正极材料的方法的流程示意图。
图2显示了本发明一个实施例提供LiNi xMn yO 2晶体的步骤的流程示意图。
图3显示了本发明实施例1和实施例2中的LiNi xMn yO 2晶体的扫描电镜照片(a图中的比例尺为2μm；b图中的比例尺为200nm)。
图4显示了本发明实施例1中的无钴层状正极材料的扫描电镜照片(a图中的比例尺为2μm；b图中的比例尺为200nm)。
图5显示了本发明实施例2中的无钴层状正极材料的扫描电镜照片(a图中的比例尺为2μm；b图中的比例尺为200nm)。
图6显示了本发明实施例1、实施例2和对比例1中的锂离子电池的首次充放电曲线(a线为实施例1中的锂离子电池的首次充放电曲线；b线为实施例2中的锂离子电池的首次充放电曲线；c线为对比例1中的锂离子电池的首次充放电曲线)。
图7显示了本发明实施例1、实施例2和对比例1中的锂离子电池的循环性能测试结果。
具体实施方式
需要说明的是，下面的描述仅用于解释本发明，而不能理解为对本发明的限制，其中未注明具体技术或条件的，按照本领域内的文献所描述的技术或条件或者按照产品说明书进行。所用试剂或仪器未注明生产厂商者，均为可以通过市购获得的常规产品。
在本发明的一个方面，本发明提供了一种用于锂离子电池的无钴层状正极材料。根据本发明的实施例，该无钴层状正极材料包括：LiNi 0.75Mn 0.25O 2晶体；和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体包括钛酸锂或者锰酸锂中的至少一种，基于所述无钴层状正极材料的总质量，所述锂离子导体的质量百分含量为0.1％～2％，其中，所述无钴层状正极材料的比表面积为0.1m 2/g～0.8m 2/g，所述无钴层状正极材料的D 50粒径为1μm～10μm。发明人发现，该无钴层状正极材料成本低、表面阻抗低、导电性好，锂离子在该无钴层状正极材料中的扩散速度快，电化学活性高，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好。
在本发明的另一个方面，本发明提供了一种用于锂离子电池的无钴层状正极材料。根据本发明的实施例，该无钴层状正极材料包括：LiNi xMn yO 2晶体，其中，x+y＝1，0.55≤x≤0.95，0.05≤y≤0.45；和锂离子导体，所述锂离子导体附着在所述LiNi xMn yO 2晶体的至少部分表面上。发明人发现，该无钴层状正极材料成本低、表面阻抗低、导电性好，锂离子在该无钴层状正极材料中的扩散速度快，电化学活性高，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好。
根据本发明的实施例，所述x可以具体为0.75；与之相对应的，所述y可以具体为0.25。本领域技术人员可以根据实际需要选择上述x和y的值。进一步地，在本发明的一些实施例中，所述LiNi xMn yO 2晶体的化学式为LiNi 0.75Mn 0.25O 2。发明人发现，当所述LiNi xMn yO 2晶体具有上述化学组成时，相较于其他化学组成的LiNi xMn yO 2晶体，锂离子晶体附着在其至少部分表面上以后，会使得该无钴层状正极材料的表面阻抗显著降低、导电性显著提高。
根据本发明的实施例，基于所述无钴层状正极材料的总质量，所述LiNi xMn yO 2晶体的质量百分含量可以是98％～99.5％。具体地，在本发明的一些实施例中，所述LiNi xMn yO 2晶体的质量百分含量可以具体为99.3％。所述LiNi xMn yO 2晶体的质量百分含量在上述范围内，可以使得该无钴层状正极材料具有较高的电化学活性，适合用在锂离子电池中。
根据本发明的实施例，进一步地，发明人对于锂离子导体的具体种类进行了深入地考察和大量的实验验证后发现，所述锂离子导体的具体种类可以包括钛酸锂或者锰酸锂等。当所述锂离子导体为钛酸锂或者锰酸锂时，该无钴层状正极材料的表面阻抗更低、导电性更好，电化学活性更高。
根据本发明的实施例，具体而言，所述锂离子导体可以为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.1％～1％。具体地，在本发明的一些实施例中，所述钛酸锂的质量百分含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％或者1％等。由此，钛酸锂在该无钴层状正极材料中的质量百分含量在上述范围内，其既不会由于钛酸锂的含量较低而导致该无钴层状正极材料的导电性能较差；也不会由于钛酸锂的含量过多而导致锂离子在该无钴层状正极材料中的扩散速度减慢。
根据本发明的实施例，另外，所述锂离子导体还可以为锰酸锂，基于所述无钴层状正极材料的总质量，所述锰酸锂的质量百分含量为0.1％～2％。具体地，在本发明的一些实施例中， 所述锰酸锂的质量百分含量可以为0.1％、0.2％、0.3％、0.4％、0.5％、0.6％、0.7％、0.8％、0.9％、1％、1.1％、1.2％、1.3％、1.4％、1.5％、1.6％、1.7％、1.8％、1.9％或者2％等。由此，锰酸锂在该无钴层状正极材料中的质量百分含量在上述范围内，其既不会由于锰酸锂的含量较低而导致该无钴层状正极材料的导电性能较差；也不会由于锰酸锂的含量过多而导致锂离子在该无钴层状正极材料中的扩散速度减慢。
根据本发明的实施例，所述无钴层状正极材料的比表面积为0.1m 2/g～0.8m 2/g。具体地，在本发明的一些实施例中，所述无钴层状正极材料的比表面积可以为0.1m 2/g、0.2m 2/g、0.3m 2/g、0.4m 2/g、0.5m 2/g、0.6m 2/g、0.7m 2/g或者0.8m 2/g等，无钴层状正极材料具有在上述范围内的比表面积，可以使得锂离子在该无钴层状正极材料中的扩散速度更快，进而电化学活性更高。
根据本发明的实施例，所述无钴层状正极材料的D 50粒径可以为1μm～10μm。具体地，在本发明的一些实施例中，所述无钴层状正极材料的粒径可以为1μm、2μm、3μm、4μm、5μm、6μm、7μm、8μm、9μm或者10μm等。发明人发现，上述无钴层状正极材料的D 50粒径为上述范围时，其电化学活性更好，进而使得由其制作得到的锂离子电池各方面的性能更好。
根据本发明的实施例，所述无钴层状正极材料呈碱性。在本发明的一些实施例中，所述无钴层状正极材料的11≤pH≤12。由此，该无钴层状正极材料更加适合用于锂离子电池的正极。
根据本发明的实施例，可以理解的是，在该无钴层状正极材料中，不可避免地还可能含有一定量的杂质，所述杂质可能是该无钴层状正极材料在制备过程中残留的碱，或者是该无钴层状正极材料放置在空气中缓慢生成的碱，基于所述无钴层状正极材料的总质量，所述杂质的质量百分含量小于等于0.5％，本领域技术人员可以理解，这并不会影响所述无钴层状正极材料的性能，在此不再过多赘述。
在本发明的另一个方面，本发明提供了一种制备前面所述的无钴层状正极材料的方法。根据本发明的实施例，参照图1，该方法包括以下步骤：
S100：提供LiNi xMn yO 2晶体。
根据本发明的实施例，具体而言，参照图2，所述LiNi xMn yO 2晶体是经由下列步骤提供的：
S110：将第二锂源、镍源和第二锰源混合，得到第二混合物。
根据本发明的实施例，具体地，所述第二锂源可以包括LiOH、Li 2CO 3、CH 3COOLi或者LiNO 3等。由此，材料来源广泛、易得，成本较低，且可以较好地提供锂源以形成LiNi xMn yO 2晶体。
根据本发明的实施例，具体地，所述镍源可以包括Ni aMn b(OH) 2，其中，0.55≤a≤0.95，0.05≤b≤0.45。具体而言，所述a可以是0.55、0.65、0.75、0.85或者0.95等；所述b可以是 0.05、0.15、0.25、0.35或者0.45等。由此，材料来源广泛、易得，成本较低，且可以较好地提供镍源以形成LiNi xMn yO 2晶体。
根据本发明的实施例，具体地，所述第二锰源可以包括Ni aMn b(OH) 2，其中，0.55≤a≤0.95，0.05≤b≤0.45。具体而言，所述a可以是0.55、0.65、0.75、0.85或者0.95等；所述b可以是0.05、0.15、0.25、0.35或者0.45等。由此，材料来源广泛、易得，成本较低，且可以较好地提供锰源以形成LiNi xMn yO 2晶体。
根据本发明的实施例，本领域技术人员可以理解，当所述镍源和所述第二锰源均为Ni aMn b(OH) 2时，所述镍源和所述第二锰源可以同时加入上述体系中，以得到所述第二混合物。由此，操作简单、方便，容易实现，易于工业化生产。
根据本发明的实施例，具体而言，在将上述原料混合时，可以是采用高速混合设备进行混合的，所述高速混合设备的转速可以为800rpm/min～900rpm/min，具体可以为800rpm/min、820rpm/min、840rpm/min、860rpm/min、880rpm/min、900rpm/min等；混合时间可以为5min～20min，具体可以为5min、10min、15min或者20min等。由此，混合效果较佳。
S120：在750℃～950℃条件下，将所述第二混合物于含有氧气的气氛中进行第二焙烧处理10h～15h，得到所述LiNi xMn yO 2晶体。
根据本发明的实施例，上述第二焙烧处理的温度可以具体为750℃、800℃、850℃、900℃、950℃、1000℃等。由此，上述温度范围是较为合适的温度范围，可以更好地进行焙烧处理，从而有效制备得到LiNi xMn yO 2晶体。
根据本发明的实施例，上述第二焙烧处理的时间可以具体为10h、11h、12h、13h、14h或者15h等。由此，上述时间范围是较为合适的时间范围，可以更好地进行焙烧处理，从而有效制备得到LiNi xMn yO 2晶体。
根据本发明的实施例，在前面所述的含有氧气的气氛中，所述氧气的体积分数大于90％，具体地，可以是91％、92％、93％、94％、95％、96％、97％、98％或者99％等。由此，可以更好地进行焙烧处理，从而有效制备得到LiNi xMn yO 2晶体。
根据本发明的实施例，本领域技术人员可以理解，在得到LiNi xMn yO 2晶体以后，还可以对其进行粉碎处理和过筛处理，所述粉碎处理可以包括相关技术中常规的粉碎处理的方式，例如可以是对辊破碎、机械粉碎或者气流粉碎等；所述过筛处理可以是过300目～400目的筛网，以除去粒径较大的杂质颗粒，其具体过程在此不再过多赘述。
S200：将所述LiNi xMn yO 2晶体和形成所述锂离子导体的材料混合，得到第一混合物。
根据本发明的实施例，具体而言，形成所述锂离子导体的材料包括：第一锂源；和钛源或者第一锰源中的至少一种。在本发明的一些实施例中，当所制备的锂离子导体为钛酸锂时，所述钛源可以具体包括钛酸四丁酯或者氧化钛等；在本发明的另一些实施例中，当所制备的锂离子导体为锰酸锂时，所述第一锰源可以具体包括碳酸锰、乙酸锰或者氧化锰等。另外， 在本发明的一些实施中，所述第一锂源可以包括LiOH、Li 2CO 3、CH 3COOLi或者LiNO 3等。由此，材料来源广泛、易得，且成本较低，可以有效制备得到前面所述的无钴层状正极材料。
根据本发明的实施例，进一步地，在将所述LiNi xMn yO 2晶体和形成所述锂离子导体的材料混合时，LiNi xMn yO 2晶体、第一锂源和钛源或者第一锰源之间的摩尔比可以(4～1)：1。具体地，可以是3：1、2：1。由此，上述投料比可以有效制备得到前面所述的性能更佳的无钴层状正极材料，其既不会由于锂离子导体的含量较低而导致该无钴层状正极材料的导电性能较差；也不会由于锂离子导体的含量过多而导致锂离子在该无钴层状正极材料中的扩散速度减慢。
S300：在600℃～800℃条件下，将所述第一混合物于含有氧气的气氛中进行第一焙烧处理5h～10h，以便得到所述无钴层状正极材料。
根据本发明的实施例，上述第一焙烧处理的温度可以具体为600℃、650℃、700℃、750℃或者800℃等。由此，上述温度范围是较为合适的温度范围，可以更好地进行焙烧处理，从而有效制备得到所述无钴层状正极材料。
根据本发明的实施例，上述第一焙烧处理的时间可以具体为5h、6h、7h、8h、9h或者10h等。由此，上述时间范围是较为合适的时间范围，可以更好地进行焙烧处理，从而有效制备得到所述无钴层状正极材料。
根据本发明的实施例，在前面所述的含有氧气的气氛中，所述氧气的体积分数大于90％，具体地，可以是91％、92％、93％、94％、95％、96％、97％、98％或者99％等。由此，可以更好地进行焙烧处理，从而有效制备得到无钴层状正极材料。
根据本发明的实施例，本领域技术人员可以理解，在得到无钴层状正极材料以后，还可以对其进行过筛处理，所述过筛处理可以是过300目～400目的筛网，以除去粒径较大的杂质颗粒，其具体过程在此不再过多赘述。
在本发明的又一个方面，本发明提供了一种正极片。根据本发明的实施例，该正极片包括前面所述的无钴层状正极材料。发明人发现，该正极片成本低、导电性好，由其制作得到的锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好，且该正极片具有前面所述的无钴层状正极材料的所有特征和优点，在此不再过多赘述。
根据本发明的实施例，除前面所述的无钴层状正极材料以外，本领域技术人员可以理解，该正极片还可以包括常规正极片的其他成分，例如基片、导电剂、粘结剂以及增稠剂等，在此不再过多赘述。
上述锂离子电池中，负极、电池隔膜、电解液等都可以是本领域的常用类型，比如电池隔膜可以是聚丙烯微孔膜(Celgard 2400)，电解液成分可以为LiPF 6(六氟磷酸锂)/EC(碳酸乙烯酯)-DMC(碳酸二甲酯))。
在本发明的再一个方面，本发明提供了一种锂离子电池。根据本发明的实施例，该锂离子电池包括：负极；正极，所述正极包括前面所述的无钴层状正极材料或前面所述的正极片；电池隔膜；和电解液。发明人发现，该锂离子电池的充电比容量高、放电比容量高、首效高、循环性能好、倍率性能好，且该锂离子电池具有前面所述的无钴层状正极材料或前面所述的正极片的所有特征和优点，在此不再过多赘述。
根据本发明的实施例，所述锂离子电池在0.1C充放电倍率的条件下，首次充电比容量不低于205.1mAh/g。由此，该锂离子电池的充电比容量高。
根据本发明的实施例，所述锂离子电池在0.1C充放电倍率的条件下，首次放电比容量不低于181.9mAh/g。由此，该锂离子电池的放电比容量高。
根据本发明的实施例，所述锂离子电池在0.1C充放电倍率的条件下，首次充放电效率不低于88.7％。由此，该锂离子电池的首效高。
根据本发明的实施例，所述锂离子电池在1C充放电倍率的条件下，所述锂离子电池在经过50次的充放电循环以后，容量保持率不低于98.3％。由此，该锂离子电池的循环性能好。
根据本发明的实施例，所述锂离子电池在0.5C充放电倍率的条件下，首次放电比容量不低于170.2mAh/g；在1C充放电倍率的条件下，首次放电比容量不低于164.8mAh/g；在2C充放电倍率的条件下，首次放电比容量不低于155.7mAh/g；在3C充放电倍率的条件下，首次放电比容量不低于149.7mAh/g；在4C充放电倍率的条件下，首次放电比容量不低于145.1mAh/g。由此，该锂离子电池的倍率性能好。
根据本发明的实施例，除前面所述的结构以外，该锂离子电池其他结构和部件的形状、构造、制造工艺等均可以为常规的形状、构造、制造工艺，在此不再过多赘述。
下面详细描述本发明的实施例。
实施例1
该无钴层状正极材料包括：
LiNi 0.75Mn 0.25O 2晶体(扫描电镜照片参见图3)；和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.2％，所述无钴层状正极材料的比表面积为0.7m 2/g，所述无钴层状正极材料的粒径为3μm。
该无钴层状正极材料的具体制备方法如下：
步骤一：采用高速混合设备将47.40gLiOH和100g前驱体Ni 0.75Mn 0.25(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行 反应，反应温度为930℃，反应时间为10h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：将步骤一获得的镍锰酸锂(100g)与0.07gLiOH、0.17gTiO 2在高速混合机里进行均匀混合，得到预混合物；然后将预混合物在700℃下反应5小时，其中反应氛围中氧气的浓度为90％，反应完之后自然降温并过400目的筛网，得到无钴层状正极材料，其中，无钴层状正极材料中的钛酸锂质量含量为0.2％。
该无钴层状正极材料的扫描电镜照片参照图4。由图3和图4可知，无钴层状正极材料的至少部分表面上附着有钛酸锂；而LiNi 0.75Mn 0.25O 2晶体的表面较为光滑，未附着有其他材料。
将该无钴层状正极材料材料经过匀浆、涂布制作成正极片，然后组装成锂离子电池，负极选用金属锂片；电池隔膜选用Celgard2400微孔聚丙烯膜；电解液选用LiPF 6(六氟磷酸锂)/EC(碳酸乙烯酯)-DMC(碳酸二甲酯)，电池型号R2032，下同。
实施例2
该无钴层状正极材料包括：
LiNi 0.75Mn 0.25O 2晶体(扫描电镜照片参见图3)；和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体为锰酸锂，基于所述无钴层状正极材料的总质量，所述锰酸锂的质量百分含量为0.15％，所述无钴层状正极材料的比表面积为0.70m 2/g，所述无钴层状正极材料的粒径为3μm。
该无钴层状正极材料的具体制备方法如下：
步骤一：和实施例1相同；
步骤二：将步骤一获得的镍锰酸锂(100g)与0.035gLiOH、0.14gMnO 2在高速混合机里进行均匀混合，得到预混合物；然后将预混合物在700℃下反应5小时，其中反应氛围中氧气的浓度为90％，反应完之后自然降温并过400目的筛网，得到无钴层状正极材料，其中，无钴层状正极材料中的钛酸锂质量含量为0.15％。
该无钴层状正极材料的扫描电镜照片参照图5。由图3和图5可知，无钴层状正极材料的至少部分表面上附着有锰酸锂；而LiNi 0.75Mn 0.25O 2晶体的表面较为光滑，未附着有其他材料。
按照与实施例1相同的方法得到锂离子电池。
实施例3
LiNi 0.75Mn 0.25O 2晶体和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸 锂的质量百分含量为0.1％，所述无钴层状正极材料的比表面积为0.1m 2/g，所述无钴层状正极材料的粒径为10μm。
步骤一：采用高速混合设备将47.40gLiOH和100g前驱体Ni 0.75Mn 0.25(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行反应，反应温度为1000℃，反应时间为15h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：将步骤一获得的镍锰酸锂(100g)与0.035gLiOH、0.085gTiO 2在高速混合机里进行均匀混合，得到预混合物；然后将预混合物在700℃下反应5小时，其中反应氛围中氧气的浓度为90％，反应完之后自然降温并过400目的筛网，得到无钴层状正极材料，其中，无钴层状正极材料中的钛酸锂质量含量为0.1％。
实施例4
LiNi 0.75Mn 0.25O 2晶体和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为2.0％，所述无钴层状正极材料的比表面积为0.8m 2/g，所述无钴层状正极材料的粒径为1μm。
步骤一：采用高速混合设备将47.40gLiOH和100g前驱体Ni 0.75Mn 0.25(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行反应，反应温度为880℃，反应时间为20h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：将步骤一获得的镍锰酸锂(100g)与0.7gLiOH、1.7gTiO 2在高速混合机里进行均匀混合，得到预混合物；然后将预混合物在700℃下反应5小时，其中反应氛围中氧气的浓度为90％，反应完之后自然降温并过400目的筛网，得到无钴层状正极材料，其中，无钴层状正极材料中的钛酸锂质量含量为2.0％
实施例5
LiNi 0.75Mn 0.25O 2晶体和锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为3.0％，所述无钴层状正极材料的比表面积为1.0m 2/g，所述无钴层状正极材料的粒径为0.5μm。
步骤一：采用高速混合设备将47.40gLiOH和100g前驱体Ni 0.75Mn 0.25(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行 反应，反应温度为850℃，反应时间为10h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：将步骤一获得的镍锰酸锂(100g)与1.05gLiOH、2.55gTiO 2在高速混合机里进行均匀混合，得到预混合物；然后将预混合物在700℃下反应5小时，其中反应氛围中氧气的浓度为90％，反应完之后自然降温并过400目的筛网，得到无钴层状正极材料，其中，无钴层状正极材料中的钛酸锂质量含量为3.0％
实施例6
LiNi 0.55Mn 0.45O 2晶体；和锂离子导体，所述锂离子导体附着在所述LiNi 0.55Mn 0.45O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.2％，所述无钴层状正极材料的比表面积为0.7m 2/g，所述无钴层状正极材料的粒径为3μm。
该无钴层状正极材料的具体制备方法如下：
步骤一：采用高速混合设备将47.0gLiOH和100g前驱体Ni 0.55Mn 0.45(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行反应，反应温度为980℃，反应时间为10h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：和实施例1相同。
实施例7
LiNi 0.95Mn 0.05O 2晶体；和锂离子导体，所述锂离子导体附着在所述LiNi 0.95Mn 0.05O 2晶体的至少部分表面上，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.2％，所述无钴层状正极材料的比表面积为0.7m 2/g，所述无钴层状正极材料的粒径为3μm。
该无钴层状正极材料的具体制备方法如下：
步骤一：采用高速混合设备将47.80gLiOH和100g前驱体Ni 0.95Mn 0.05(OH) 2进行混合，混合时间为10分钟，转速为800rpm；将混合好的物料在氧气氛围(浓度大于等于90％)下进行反应，反应温度为800℃，反应时间为10h，反应完之后自然降温并过400目的筛网，得到单晶形貌的层状镍锰酸锂；
步骤二：和实施例1相同；
对比例1
该无钴层状正极材料包为：LiNi 0.55Mn 0.45O 2晶体。所述无钴层状正极材料的比表面积为0.7m 2/g，所述无钴层状正极材料的粒径为3μm。
步骤一：和实施例6相同。
性能测试结果：
(1)实施例1、实施例2和对比例1中的锂离子电池的首次充放电曲线参照图6。由图6可知，对比例1中的锂离子电池在0.1C充放电倍率的条件下，首次充电和放电比容量分别为200.7mAh/g和172.5mAh/g，首次效率为85.9％；实施例1中的锂离子电池在0.1C充放电倍率的条件下，首次充电和放电比容量为205.1和181.9mAh/g，首次效率为88.7％；实施例2中的锂离子电池在0.1C充放电倍率的条件下，首次充电和放电比容量为209.1mAh/g和185.7mAh/g，首次效率为88.9％。由此，本发明所述的无钴层状正极材料制作得到的锂离子电池的充电比容量高、放电比容量高、首次效率高。
(2)实施例1、实施例2和对比例1中的锂离子电池的循环性能测试结果参照图7，其中，测试时温度为25℃、充电倍率为0.5C、放电倍率为1C，电位范围为3.0V～4.3V。由图7可知，对比例1中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率仅为96.9％；实施例1中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为99.2％；实施例2中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为98.3％。实施例2中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为98.3％；实施例3中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为97.6％；实施例4中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为98.9％；实施例5中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为96.3％；实施例6中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为97.5％；实施例7中的锂离子电池在1C充放电倍率的条件下，经过充放电循环50次以后，容量保持率为95.1％。由此，本发明所述的无钴层状正极材料的循环性能好。
(3)实施例1、实施例2和对比例1中的锂离子电池的倍率性能测试结果参照表1。由表1可知，实施例1和实施例2相较于对比例1，其倍率性能有显著的提升。例如，在充放电倍率为1C的条件下，对比例1的放电比容量仅为155.3mAh/g，实施例1的放电比容量达到164.8mAh/g；在充放电倍率为4C的条件下，对比例1的放电比容量仅为136.3mAh/g，实施例1的放电比容量达到145.1mAh/g，实施例2的放电比容量达到147.4mAh/g。由此，本发明所述的无钴层状正极材料的倍率性能好。其余实施例中锂离子电池的倍率性能测试结果见下表1。
表1
Figure PCTCN2020132906-appb-000001
在本发明的描述中，需要理解的是，术语“第一”、“第二”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”的特征可以明示或者隐含地包括一个或者更多个该特征。在本发明的描述中，“多个”的含义是两个或两个以上，除非另有明确具体的限定。
在本说明书的描述中，参考术语“一个实施例”、“一些实施例”、“示例”、“具体示例”、或“一些示例”等的描述意指结合该实施例或示例描述的具体特征、结构、材料或者特点包含于本发明的至少一个实施例或示例中。在本说明书中，对上述术语的示意性表述不必须针对的是相同的实施例或示例。而且，描述的具体特征、结构、材料或者特点可以在任一个或多个实施例或示例中以合适的方式结合。此外，在不相互矛盾的情况下，本领域的技术人员可以将本说明书中描述的不同实施例或示例以及不同实施例或示例的特征进行结合和组合。
尽管上面已经示出和描述了本发明的实施例，可以理解的是，上述实施例是示例性的，不能理解为对本发明的限制，本领域的普通技术人员在本发明的范围内可以对上述实施例进行变化、修改、替换和变型。

Claims (10)

  1. 一种用于锂离子电池的无钴层状正极材料，其特征在于，包括：
    LiNi 0.75Mn 0.25O 2晶体；和
    锂离子导体，所述锂离子导体附着在所述LiNi 0.75Mn 0.25O 2晶体的至少部分表面上，所述锂离子导体包括钛酸锂或者锰酸锂中的至少一种，基于所述无钴层状正极材料的总质量，所述锂离子导体的质量百分含量为0.1％～2％，
    其中，所述无钴层状正极材料的比表面积为0.1m 2/g～0.8m 2/g，所述无钴层状正极材料的D 50粒径为1μm～10μm。
  2. 一种用于锂离子电池的无钴层状正极材料，其特征在于，包括：
    LiNi xMn yO 2晶体，其中，x+y＝1，0.55≤x≤0.95，0.05≤y≤0.45；和
    锂离子导体，所述锂离子导体附着在所述LiNi xMn yO 2晶体的至少部分表面上。
  3. 根据权利要求2所述的无钴层状正极材料，其特征在于，所述锂离子导体包括钛酸锂或者锰酸锂中的至少一种，
    任选地，所述锂离子导体为钛酸锂，基于所述无钴层状正极材料的总质量，所述钛酸锂的质量百分含量为0.1％～1％，
    任选地，所述锂离子导体为锰酸锂，基于所述无钴层状正极材料的总质量，所述锰酸锂的质量百分含量为0.1％～2％。
  4. 根据权利要求2或3所述的无钴层状正极材料，其特征在于，满足以下条件的至少之一：
    比表面积为0.1m 2/g～0.8m 2/g；
    D 50粒径为1μm～10μm；
    所述x为0.75，所述y为0.25。
  5. 一种制备权利要求2～4中任一项所述的无钴层状正极材料的方法，其特征在于，包括：
    提供LiNi xMn yO 2晶体；
    将所述LiNi xMn yO 2晶体和形成所述锂离子导体的材料混合，得到第一混合物；
    在600℃～800℃条件下，将所述第一混合物于含有氧气的气氛中进行第一焙烧处理5h～10h，以便得到所述无钴层状正极材料。
  6. 根据权利要求5所述的方法，其特征在于，形成所述锂离子导体的材料包括：
    第一锂源；和
    钛源或者第一锰源中的至少一种，
    任选地，所述钛源包括钛酸四丁酯或者氧化钛中的至少一种，
    任选地，所述第一锰源包括碳酸锰、乙酸锰或者氧化锰中的至少一种。
  7. 根据权利要求6所述的方法，其特征在于，所述LiNi xMn yO 2晶体是经由下列步骤提供的：
    将第二锂源、镍源和第二锰源混合，得到第二混合物；
    在750℃～1000℃条件下，将所述第二混合物于含有氧气的气氛中进行第二焙烧处理10h～15h，得到所述LiNi xMn yO 2晶体，
    任选地，所述第一锂源和所述第二锂源各自独立地包括LiOH、Li 2CO 3、CH 3COOLi或者LiNO 3中的至少一种，
    任选地，所述镍源和所述第二锰源各自独立地包括Ni aMn b(OH) 2，其中，0.55≤a≤0.95，0.05≤b≤0.45。
  8. 一种正极片，其特征在于，包括权利要求1～4中任一项所述的无钴层状正极材料。
  9. 一种锂离子电池，其特征在于，包括：
    负极；
    正极，所述正极包括权利要求1～4中任一项所述的无钴层状正极材料或权利要求8所述的正极片；
    电池隔膜；
    电解液。
  10. 根据权利要求9所述的锂离子电池，其特征在于，满足以下条件的至少之一：
    在0.1C充放电倍率的条件下，首次充电比容量不低于205.1mAh/g；
    在0.1C充放电倍率的条件下，首次放电比容量不低于181.9mAh/g；
    在0.1C充放电倍率的条件下，首次充放电效率不低于88.7％；
    在1C充放电倍率的条件下，所述锂离子电池在经过50次的充放电循环以后，容量保持率不低于98.3％；
    在0.5C充放电倍率的条件下，首次放电比容量不低于170.2mAh/g；
    在1C充放电倍率的条件下，首次放电比容量不低于164.8mAh/g；
    在2C充放电倍率的条件下，首次放电比容量不低于155.7mAh/g；
    在3C充放电倍率的条件下，首次放电比容量不低于149.7mAh/g；
    在4C充放电倍率的条件下，首次放电比容量不低于145.1mAh/g。
PCT/CN2020/132906 2020-01-17 2020-11-30 无钴层状正极材料及其制备方法、正极片和锂离子电池 WO2021143374A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP20913588.8A EP3998659A4 (en) 2020-01-17 2020-11-30 COBALT-FREE LAYERED POSITIVE ELECTRODE MATERIAL AND PREPARATION METHOD THEREFOR, POSITIVE ELECTRODE PLATE AND LITHIUM-ION BATTERY
US17/764,551 US20220340446A1 (en) 2020-01-17 2020-11-30 Cobalt-free lamellar cathode material and method for preparing cobalt-free lamellar cathode material, cathode piece and lithium ion battery
KR1020217028403A KR20210134658A (ko) 2020-01-17 2020-11-30 무-코발트 층상 양극 재료 및 이의 제조 방법, 양극판 및 리튬 이온 전지
JP2022509609A JP7326588B2 (ja) 2020-01-17 2020-11-30 コバルトフリー層状正極材料及びその製造方法、正極シート並びにリチウムイオン電池

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202010054701.9A CN111435744B (zh) 2020-01-17 2020-01-17 无钴层状正极材料及其制备方法、正极片和锂离子电池
CN202010054701.9 2020-01-17

Publications (1)

Publication Number Publication Date
WO2021143374A1 true WO2021143374A1 (zh) 2021-07-22

Family

ID=71580207

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/132906 WO2021143374A1 (zh) 2020-01-17 2020-11-30 无钴层状正极材料及其制备方法、正极片和锂离子电池

Country Status (6)

Country Link
US (1) US20220340446A1 (zh)
EP (1) EP3998659A4 (zh)
JP (1) JP7326588B2 (zh)
KR (1) KR20210134658A (zh)
CN (1) CN111435744B (zh)
WO (1) WO2021143374A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113716614A (zh) * 2021-08-31 2021-11-30 蜂巢能源科技有限公司 无钴无镍正极材料及其制备方法和锂离子电池

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111435744B (zh) * 2020-01-17 2022-04-12 蜂巢能源科技有限公司 无钴层状正极材料及其制备方法、正极片和锂离子电池
CN113060775B (zh) * 2021-03-26 2022-10-28 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
CN113517424A (zh) * 2021-04-27 2021-10-19 湖南杉杉能源科技股份有限公司 一种高电压锂离子电池无钴正极材料及其制备方法
CN113707870A (zh) * 2021-10-29 2021-11-26 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
KR102669802B1 (ko) * 2022-06-30 2024-05-27 에스케이온 주식회사 리튬 이차 전지용 양극 및 이를 포함하는 리튬 이차 전지

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1658415A (zh) * 2004-02-16 2005-08-24 索尼株式会社 正极活性材料和无水电解质二次电池
CN103490055A (zh) * 2013-09-06 2014-01-01 中国海洋石油总公司 一种镍钴锰酸锂复合正极材料的制备方法
CN104425809A (zh) * 2013-08-28 2015-03-18 奇瑞汽车股份有限公司 锂离子电池正极材料及其制备方法、含有该材料的锂离子电池
CN111435744A (zh) * 2020-01-17 2020-07-21 蜂巢能源科技有限公司 无钴层状正极材料及其制备方法、正极片和锂离子电池

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5430920B2 (ja) * 2008-03-17 2014-03-05 三洋電機株式会社 非水電解質二次電池
US20120135315A1 (en) * 2009-08-07 2012-05-31 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary battery
JP5784961B2 (ja) * 2011-04-28 2015-09-24 国立大学法人高知大学 被覆活物質の製造方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1658415A (zh) * 2004-02-16 2005-08-24 索尼株式会社 正极活性材料和无水电解质二次电池
CN104425809A (zh) * 2013-08-28 2015-03-18 奇瑞汽车股份有限公司 锂离子电池正极材料及其制备方法、含有该材料的锂离子电池
CN103490055A (zh) * 2013-09-06 2014-01-01 中国海洋石油总公司 一种镍钴锰酸锂复合正极材料的制备方法
CN111435744A (zh) * 2020-01-17 2020-07-21 蜂巢能源科技有限公司 无钴层状正极材料及其制备方法、正极片和锂离子电池

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3998659A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113716614A (zh) * 2021-08-31 2021-11-30 蜂巢能源科技有限公司 无钴无镍正极材料及其制备方法和锂离子电池
CN113716614B (zh) * 2021-08-31 2023-07-21 蜂巢能源科技有限公司 无钴无镍正极材料及其制备方法和锂离子电池

Also Published As

Publication number Publication date
JP2022546936A (ja) 2022-11-10
CN111435744B (zh) 2022-04-12
JP7326588B2 (ja) 2023-08-15
EP3998659A4 (en) 2023-12-13
KR20210134658A (ko) 2021-11-10
CN111435744A (zh) 2020-07-21
EP3998659A1 (en) 2022-05-18
US20220340446A1 (en) 2022-10-27

Similar Documents

Publication Publication Date Title
WO2021143374A1 (zh) 无钴层状正极材料及其制备方法、正极片和锂离子电池
CN110931768B (zh) 一种高镍类单晶锂离子电池正极材料及制备方法
JP7094248B2 (ja) リチウム二次電池用ニッケル系活物質前駆体、その製造方法、そこから形成されたリチウム二次電池用ニッケル系活物質、及びそれを含む正極を含んだリチウム二次電池
WO2021143376A1 (zh) 锂离子电池的无钴正极材料及其制备方法和锂离子电池
JP7392132B2 (ja) コバルトフリー正極材料およびその調製方法
WO2016188477A2 (zh) 碳包覆三元正极材料及其制备方法、锂离子电池
WO2018094783A1 (zh) 锂离子电池用硅基锡基复合颗粒、其制备方法、包含其的负极和锂离子电池
WO2021129109A1 (zh) 一种锂离子电池的无钴正极材料及其制备方法和锂离子电池
WO2021143375A1 (zh) 无钴层状正极材料及其制备方法和锂离子电池
WO2021143373A1 (zh) 无钴层状正极材料及其制备方法、锂离子电池
JP6871320B2 (ja) リチウム二次電池用ニッケル系活物質前駆体、その製造方法、それから形成されたリチウム二次電池用ニッケル系活物質、及びそれを含む正極を含んだリチウム二次電池
CN109841822A (zh) 一种锂离子电池用改性单晶三元正极材料的制备方法
CN113871603A (zh) 一种高镍三元正极材料及其制备方法
CN116504954B (zh) 一种正极材料及其制备方法和钠离子电池
CN110854370A (zh) 一种高镍镍钴锰酸锂正极材料的制备方法
JP2023143694A (ja) 正極材料、電池及び電子機器
WO2023046137A1 (zh) 制备磷酸铁锂正极材料的方法、正极极片及锂离子电池
JP2011249293A (ja) リチウム遷移金属化合物及びその製造方法、並びにリチウムイオン電池
CN115939370A (zh) 钠离子正极材料及其制备方法、二次电池
CN113764638A (zh) 正极材料、其制备方法、包括其的正极和锂离子电池
WO2024087568A1 (zh) 一种锰基固溶体正极材料及制备方法与用途
CN116230908A (zh) 补锂剂、正极极片、电化学装置及补锂剂的制备方法
CN111342012B (zh) 介孔球型二氧化钛包覆三元材料及其制备方法、锂离子电池正极和锂离子电池
KR20190024308A (ko) 리튬이차전지용 양극활물질 및 그 제조방법
JP7495439B2 (ja) リチウム二次電池用正極活物質、その製造方法およびこれを含むリチウム二次電池

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: 20913588

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2022509609

Country of ref document: JP

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2020913588

Country of ref document: EP

Effective date: 20220208

NENP Non-entry into the national phase

Ref country code: DE