Nothing Special   »   [go: up one dir, main page]

CN106711412B - Composite lithium-rich manganese-based positive electrode material and preparation method thereof - Google Patents

Composite lithium-rich manganese-based positive electrode material and preparation method thereof Download PDF

Info

Publication number
CN106711412B
CN106711412B CN201611147525.3A CN201611147525A CN106711412B CN 106711412 B CN106711412 B CN 106711412B CN 201611147525 A CN201611147525 A CN 201611147525A CN 106711412 B CN106711412 B CN 106711412B
Authority
CN
China
Prior art keywords
rich manganese
positive electrode
solution
electrode material
based positive
Prior art date
Legal status (The legal status 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 status listed.)
Active
Application number
CN201611147525.3A
Other languages
Chinese (zh)
Other versions
CN106711412A (en
Inventor
苏岳锋
李翌通
包丽颖
吴锋
卢赟
王敬
陈实
陈来
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Beijing Institute of Technology BIT
Original Assignee
Beijing Institute of Technology BIT
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 Beijing Institute of Technology BIT filed Critical Beijing Institute of Technology BIT
Priority to CN201611147525.3A priority Critical patent/CN106711412B/en
Publication of CN106711412A publication Critical patent/CN106711412A/en
Application granted granted Critical
Publication of CN106711412B publication Critical patent/CN106711412B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • H01M4/36—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
    • 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
    • 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
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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

Landscapes

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

Abstract

The invention relates to a composite lithium-rich manganese-based positive electrode material and a preparation method thereof, belonging to the field of chemical energy storage batteries. The anode material is a composite material with a core-shell structure, and NaZr with uniform deposition thickness is prepared on the surface of the lithium-rich manganese-based anode material by utilizing a complexing method2(PO4)3A coating layer; and by changing the NaZr2(PO4)3And the mass ratio of the lithium-rich manganese-based positive electrode material to the lithium-rich manganese-based positive electrode material can obtain coating layers with different shapes, structures and arrangements. NaZr2(PO4)3Presence of a coating layer to Li+The migration and diffusion of the carbon dioxide are improved in different degrees, and further the electrochemical performance is improved in different degrees; the composite lithium-rich manganese-based positive electrode material can realize high-rate charge and discharge of a battery, and improves the cycle stability of the battery.

Description

Composite lithium-rich manganese-based positive electrode material and preparation method thereof
Technical Field
The invention relates to a composite lithium-rich manganese-based positive electrode material and a preparation method thereof, belonging to the field of chemical energy storage batteries.
Background
The fundamental problem facing the world today is energy and environment. The two problems concern the survival of human beings and simultaneously restrict the development of the human beings everywhere. As one of the biggest contributions of traditional fossil energy, the automobile brings people convenient traveling and simultaneously causes a series of problems of air pollution, noise pollution, traffic jam and the like. In order to solve these problems, new energy electric vehicles have increasingly entered our lives in recent years. With the popularization of electric vehicles, lithium ion batteries are used as power sources of the electric vehicles, the performance of the lithium ion batteries is urgently to be improved, and the country proposes that the specific energy of a lithium ion power battery monomer is improved to 200Wh/Kg and the cost is reduced to below 0.8 yuan/watt hour in 2020. To achieve this goal, the development of a new generation of high capacity positive electrode materials is not slow.
Lithium-rich manganese-based cathode material Li1.2Mn0.6Ni0.2O2As a novel anode material still in the research stage, the lithium ion battery anode material has the characteristics of high specific capacity, low cost, environmental friendliness and the like, and is one of the lithium ion battery anode materials which have the most potential and can meet the national 2020 target. However, the lithium-rich manganese-based positive electrode material still faces many problems, among which, firstly, the rate capability should be improved, and the rate capability is also the key to whether the power battery can provide enough power. The key point of improving the rate performance of the material is to improve the migration rate of lithium ions in the lithium-rich material and provide more diffusion channels for the lithium ions.
Thackeray et al used to coat an amorphous LiNiPO on the surface of a lithium-rich cathode material4The method of (1) reduces the impedance between the surface of the material and the electrolyte, thereby improving the rate capability of the material (Kang, S. -H.; Thackeray, M.M. electrochemistry Communications 2009,11(4), 748-. The research shows that the surface coating modification method can not only retain the advantages of the lithium-rich manganese-based positive electrode material, but also improve the rate capability of the lithium-rich manganese-based positive electrode material. But amorphous LiNiPO4The structure of the cladding layer is not stable enough and the conductivity is poor. Therefore, the selection of a suitable coating material and the corresponding coating method are of great importanceAnd (5) defining.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a composite lithium-rich manganese-based positive electrode material and a preparation method thereof, wherein NaZr is adopted2(PO4)3For Li1.2Mn0.6Ni0.2O2The surface is coated with NaZr2(PO4)3The lithium-rich material can be protected from being corroded by electrolyte, the polarization phenomenon in the electrochemical reaction process can be reduced, and the prepared composite lithium-rich manganese-based positive electrode material has good high-rate charge and discharge performance and good circulation stability.
The purpose of the invention is realized by the following technical scheme:
the composite lithium-rich manganese-based positive electrode material is a composite material with a core-shell structure, and Li1.2Mn0.6Ni0.2O2As a nuclear material, NaZr2(PO4)3Is a surface coating layer.
The Li1.2Mn0.6Ni0.2O2The particle diameter of (B) is preferably 0.1 to 0.4. mu.m.
NaZr2(PO4)3The thickness of the coating layer is preferably 2nm to 10 nm.
The invention relates to a preparation method of a composite lithium-rich manganese-based positive electrode material, which comprises the following steps:
step 1, dissolving sodium salt, zirconium salt, phosphate and a complexing agent into a solvent, and uniformly mixing to obtain a coating solution;
step 2. mixing Li1.2Mn0.6Ni0.2O2Fully mixing the precursor with the coating solution, and evaporating the solvent to obtain a composite material precursor;
and 3, under a protective atmosphere, pre-sintering the composite material precursor at 200-300 ℃ for 2-3 h, then calcining at 600-700 ℃ for 5-6 h, and cooling to obtain the composite lithium-rich manganese-based positive electrode material.
The sodium salt is sodium carbonate, sodium hydroxide, sodium dihydrogen phosphate, sodium nitrate, sodium bicarbonate, sodium chloride or sodium acetate.
The zirconium salt is zirconium carbonate or zirconium nitrate.
The phosphate is diammonium hydrogen phosphate, ammonium dihydrogen phosphate or sodium dihydrogen phosphate.
The complexing agent is citric acid, ammonium oxalate, ammonium citrate, polyvinylpyrrolidone (PVP), diethanolamine, triethanolamine or disodium ethylene diamine tetraacetate.
The solvent is HCl aqueous solution, NaCl aqueous solution, propane, N-dimethylacetamide, acetic acid, tetrahydrofuran, absolute ethyl alcohol, hexafluoroacetone, trichloromethane or water.
The gas of the protective atmosphere is argon or nitrogen.
In the coating solution prepared in the step 1, the mole number of sodium element is as follows: molar number of zirconium element: the mole number of the phosphorus element is 1-1.5: 2: 3-3.5; NaZr2(PO4)3The mass ratio of the coating layer to the complexing agent is 1: 10-30.
In the prepared composite lithium-rich manganese-based cathode material, Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3The mass ratio of the coating layer is 1: 0.01-0.3.
Preferably, the coating solution in step 1 is prepared by the following method:
step a, respectively dissolving sodium salt, zirconium salt, phosphate and a complexing agent in a solvent, and uniformly mixing to respectively obtain a sodium salt solution, a zirconium salt solution, a phosphate solution and a complexing agent solution;
and b, adding the sodium salt solution, the zirconium salt solution and the phosphate solution into the complexing agent solution, and uniformly mixing to obtain a coating solution.
In the step a, the conditions for preparing the sodium salt solution, the zirconium salt solution and the phosphate solution are as follows: the temperature is 45-80 ℃, the stirring time is 0.5-1 h, and the stirring speed is 100-500 rmp.
In the step a, the conditions for preparing the complexing agent solution are as follows: the temperature is 30-50 ℃, the stirring time is 5-8 h, and the stirring speed is 100-500 rmp.
In the step b, the solution is uniformly mixed under the following conditions: the temperature is 30-50 ℃, the stirring time is 0.5-2 h, and the stirring speed is 100-500 rmp.
In step 2, the conditions for evaporating the solvent are as follows: the temperature is 60-90 ℃, the stirring time is 6-8 h, and the stirring speed is 100-1000 rmp.
Has the advantages that:
firstly, the method comprises the following steps: the invention utilizes the complexing method to prepare the NaZr2(PO4)3The coating layer has a uniform thickness and is formed by changing the NaZr2(PO4)3The coating layers with different shapes, structures and arrangements can be obtained according to the mass ratio of the lithium-rich manganese-based positive electrode material to the lithium-rich manganese-based positive electrode material; NaZr in amorphous, amorphous and crystalline composite states and crystalline states2(PO4)3Presence of a coating layer to Li+The migration and diffusion of the carbon dioxide are improved to different degrees, and further, the electrochemical performance is improved to different degrees.
Secondly, the method comprises the following steps: NaZr2(PO4)3As a fast ion conductor, in the amorphous and crystal composite coating layer, the diffusion path of the crystal coating layer is short, the stability of the structure is facilitated, the amorphous coating layer can provide more transportation channels, and the fast de-intercalation of lithium ions in the surface coating layer is facilitated; crystalline or amorphous NaZr2(PO4)3The coating layer can protect the lithium-rich material of the body from being corroded by electrolyte, so that structural change of the material of the body caused by the electrolyte is reduced, and the polarization phenomenon in the electrochemical reaction process is reduced.
Thirdly, the method comprises the following steps: the composite lithium-rich manganese-based positive electrode material prepared by the invention can realize high-rate charge and discharge of the battery and improve the cycle stability of the battery.
Drawings
Fig. 1 is a comparison graph of X-ray diffraction (XRD) spectra of the composite lithium-rich manganese-based positive electrode materials prepared in examples 1 to 4.
Fig. 2 is a partial enlarged view of an XRD spectrum in the interval of 29 to 32 ° 2 θ in fig. 1.
Fig. 3 is a partial enlarged view of an XRD spectrum in the interval of 42.5 to 47 ° 2 θ in fig. 1.
Fig. 4 is a high-definition Transmission Electron Microscope (TEM) image of the composite lithium-rich manganese-based positive electrode material prepared in example 1.
Fig. 5 is a high-definition transmission electron microscope image of the composite lithium-rich manganese-based positive electrode material prepared in example 2.
Fig. 6 is a high-definition transmission electron microscope image of the composite lithium-rich manganese-based positive electrode material prepared in example 3.
Fig. 7 is a high-definition transmission electron microscope image of the composite lithium-rich manganese-based positive electrode material prepared in example 4.
Fig. 8 is a graph of the cycle performance of the CR2050 experimental coin cell prepared in example 2 after charging and discharging for 50 weeks at 1C.
Fig. 9 is a graph of the cycling performance of CR2050 experimental coin cells prepared in example 2 at 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, and 10C.
Detailed Description
The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.
In the following examples and comparative examples:
the LAND CT2001A tester was purchased from blue-ray electronics, Inc., Wuhan, Inc.;
x-ray diffraction testing: instrument model Dmax-2400, available from japan;
testing by a high-definition transmission electron microscope: the instrument model is as follows: JEM-2100ST, available from electronics of Japan.
Example 1
Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3When the mass ratio of the coating layer is 1:0.03, the preparation steps of the composite lithium-rich manganese-based positive electrode material are as follows:
step 1, dissolving 0.0053g of sodium nitrate in 2mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a sodium salt solution; dissolving 0.0525g of pentahydrate zirconium nitrate in 3mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a zirconium salt solution; dissolving 0.0215g of ammonium dihydrogen phosphate in 5mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a phosphate solution; dissolving 0.6g of polyvinylpyrrolidone with the average molecular weight of 1300000 in 10mL of deionized water, and stirring for 6 hours at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a complexing agent solution;
step 2, adding the sodium salt solution, the zirconium salt solution and the phosphate solution prepared in the step 1 into a complexing agent solution, and stirring for 0.5h at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a coating solution; wherein n (Na) in the coating solution+):n(Zr4 +):n(PO4 3-)＝1.02:2:3.05；
Step 3, 1g of Li with the grain diameter of 0.1-0.4 mu m1.2Mn0.6Ni0.2O2Adding the mixture into the coating solution obtained in the step 2, and stirring for 7 hours at 65 ℃ and a stirring speed of 400rpm until the water is completely evaporated to dryness to obtain a composite material precursor;
and 4, placing the composite material precursor in a tubular furnace, introducing argon, heating to 300 ℃ at the heating rate of 5 ℃/min, presintering for 3 hours, heating to 700 ℃ at the heating rate of 5 ℃/min, calcining for 6 hours, and cooling along with the furnace to obtain the NaZr2(PO4)3And (3) coating the composite lithium-rich manganese-based positive electrode material.
FIG. 4 is a TEM image of the composite lithium-rich manganese-based positive electrode material prepared in this example, from which it can be seen that NaZr2(PO4)3The coating layer is uniformly distributed on Li1.2Mn0.6Ni0.2O2A surface having a thickness of about 3.1 nm; NaZr2(PO4)3Is an amorphous structure.
Example 2
Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3When the mass ratio of the coating layer is 1:0.05, the preparation steps of the composite lithium-rich manganese-based positive electrode material are as follows:
step 1, dissolving 0.0088g of sodium nitrate in 2mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a sodium salt solution; dissolving 0.0876g of zirconium nitrate pentahydrate in 3mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a zirconium salt solution; dissolving 0.0357g of ammonium dihydrogen phosphate in 5mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a phosphate solution; dissolving 1g of polyvinylpyrrolidone with the average molecular mass of 1300000 in 10mL of deionized water, and stirring for 7 hours at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a complexing agent solution;
step 2, adding the sodium salt solution, the zirconium salt solution and the phosphate solution prepared in the step 1 into a complexing agent solution, and stirring for 0.5h at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a coating solution; wherein n (Na) in the coating solution+):n(Zr4 +):n(PO4 3-)＝1.02:2:3.05；
Step 3, 1g of Li with the grain diameter of 0.1-0.4 mu m1.2Mn0.6Ni0.2O2Adding the mixture into the coating solution obtained in the step 2, and stirring for 7 hours at 65 ℃ and a stirring speed of 400rpm until the water is completely evaporated to dryness to obtain a composite material precursor;
and 4, placing the composite material precursor in a tubular furnace, introducing argon, heating to 300 ℃ at the heating rate of 5 ℃/min, presintering for 3 hours, heating to 700 ℃ at the heating rate of 5 ℃/min, calcining for 6 hours, and cooling along with the furnace to obtain the NaZr2(PO4)3And (3) coating the composite lithium-rich manganese-based positive electrode material.
FIG. 5 is a TEM image of the composite lithium-rich manganese-based positive electrode material prepared in this example, from which it can be seen that NaZr2(PO4)3The coating layer is uniformly distributed on Li1.2Mn0.6Ni0.2O2A surface; NaZr2(PO4)3The thickness of the coating layer with the amorphous structure is about 3.7nm for the mixed structure of amorphous and crystal, and the crystal lattice fringes of the coating layer with the crystal structure grow well and are about 2.5nm in thickness.
Example 3
Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3When the mass ratio of the coating layer is 1:0.07, the preparation steps of the composite lithium-rich manganese-based positive electrode material are as follows:
step 1, dissolving 0.0124g of sodium nitrate in 2mL of deionized water, and stirring at 50 ℃ and a stirring speed of 500rpm for 0.5h to obtain a sodium salt solution; 0.1225g of zirconium nitrate pentahydrate is dissolved in 3mL of deionized water, and the solution is stirred for 0.5h at 50 ℃ and a stirring speed of 500rpm to obtain a zirconium salt solution; 0.0501g of ammonium dihydrogen phosphate is dissolved in 5mL of deionized water, and the mixture is stirred for 1h at 50 ℃ and a stirring speed of 500rpm to obtain a phosphate solution; dissolving 1.4g of polyvinylpyrrolidone with the average molecular weight of 1300000 in 15mL of deionized water, and stirring for 7 hours at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a complexing agent solution;
step 2, adding the sodium salt solution, the zirconium salt solution and the phosphate solution prepared in the step 1 into a complexing agent solution, and stirring for 1h at the temperature of 30 ℃ and the stirring speed of 500rpm to obtain a coating solution; wherein n (Na) in the coating solution+):n(Zr4+):n(PO4 3-)＝1.02:2:3.05；
Step 3, 1g of Li with the grain diameter of 0.1-0.4 mu m1.2Mn0.6Ni0.2O2Adding the mixture into the coating solution obtained in the step 2, and stirring for 8 hours at 65 ℃ and a stirring speed of 400rpm until the water is completely evaporated to dryness to obtain a composite material precursor;
and 4, placing the composite material precursor in a tubular furnace, introducing argon, heating to 300 ℃ at the heating rate of 5 ℃/min, presintering for 3 hours, heating to 700 ℃ at the heating rate of 5 ℃/min, calcining for 6 hours, and cooling along with the furnace to obtain the NaZr2(PO4)3And (3) coating the composite lithium-rich manganese-based positive electrode material.
FIG. 6 is a TEM image of the composite lithium-rich manganese-based positive electrode material prepared in this example, from which it can be seen that NaZr2(PO4)3The coating layer is uniformly distributed on Li1.2Mn0.6Ni0.2O2A surface; NaZr2(PO4)3The crystal structure is good in lattice stripe growth and the thickness is about 3.5 nm.
Example 4
Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3When the mass ratio of the coating layer is 1:0.05, the preparation steps of the composite lithium-rich manganese-based positive electrode material are as follows:
step 1, dissolving 0.0091g of sodium nitrate in 2mL of absolute ethyl alcohol, and stirring at 35 ℃ and a stirring speed of 400rpm for 0.5h to obtain a sodium salt solution; dissolving 0.0876g of zirconium nitrate pentahydrate in 3mL of absolute ethyl alcohol, and stirring at 40 ℃ and a stirring speed of 400rpm for 0.5h to obtain a zirconium salt solution; dissolving 0.0355g of ammonium dihydrogen phosphate in 5mL of absolute ethyl alcohol, and stirring at 40 ℃ and a stirring speed of 400rpm for 0.5h to obtain a phosphate solution; dissolving 1.3g of polyvinylpyrrolidone with the average molecular weight of 1300000 in 10mL of deionized water, and stirring for 7 hours at 35 ℃ and the stirring speed of 400rpm to obtain a complexing agent solution;
step 2, adding the sodium salt solution, the zirconium salt solution and the phosphate solution prepared in the step 1 into a complexing agent solution, and stirring for 0.5h at 35 ℃ and a stirring speed of 500rpm to obtain a coating solution; wherein n (Na) in the coating solution+):n(Zr4 +):n(PO4 3-)＝1.05:2:3.02；
Step 3, 1g of Li with the grain diameter of 0.1-0.4 mu m1.2Mn0.6Ni0.2O2Adding the mixture into the coating solution obtained in the step 2, and stirring for 7 hours at 65 ℃ and a stirring speed of 400rpm until the water is completely evaporated to dryness to obtain a composite material precursor;
and 4, placing the composite material precursor in a tubular furnace, introducing argon, heating to 300 ℃ at the heating rate of 5 ℃/min, presintering for 3 hours, heating to 600 ℃ at the heating rate of 5 ℃/min, calcining for 6 hours, and cooling along with the furnace to obtain the NaZr2(PO4)3And (3) coating the composite lithium-rich manganese-based positive electrode material.
FIG. 7 is a TEM image of the composite lithium-rich manganese-based positive electrode material prepared in this example, from which it can be seen that NaZr2(PO4)3The coating layer is uniformly distributed on Li1.2Mn0.6Ni0.2O2A surface; NaZr2(PO4)3For amorphous structures, the thickness of the coating layer of the amorphous structure is about 4.76 nm.
FIG. 1 is an XRD (X-ray diffraction) pattern of the composite lithium-rich manganese-based positive electrode material prepared in examples 1-4, and it can be seen from the XRD pattern that the peak shapes of the three XRD patterns are approximately the same, the peak intensities are similar, and the main peaks can be well matched with the R3m space group, which shows that the NaZr is2(PO4)3The coating layer does not damage Li1.2Mn0.6Ni0.2O2The internal structure of (1). Except that in the interval of 29-32 degrees for 2 theta in fig. 2 and the interval of 43-44 degrees for 2 theta in fig. 3, two miscellaneous peaks with gradually increased intensity appear in the XRD spectra of the composite lithium-rich manganese-based positive electrode materials prepared in examples 2 and 3, which correspond to the gradually increased thickness of NaZr in TEM pictures2(PO4)3A crystalline phase of the coating layer.
Comparative example
1g of Li having a particle diameter of 0.1 to 0.4. mu.m1.2Mn0.6Ni0.2O2Placing the lithium-rich manganese-based anode material in a tubular furnace, introducing argon, heating to 300 ℃ at the heating rate of 5 ℃/min, pre-sintering for 3h, heating to 700 ℃ at the heating rate of 5 ℃/min, calcining for 6h, and cooling along with the furnace to obtain the heat-treated lithium-rich manganese-based anode material.
Respectively and uniformly mixing the composite lithium-rich manganese-based positive electrode material prepared in the embodiments 1-4 and the heat-treated lithium-rich manganese-based positive electrode material prepared in proportion with acetylene black and a binder PVDF (5% polyvinylidene fluoride solution) according to a mass ratio of 8:1:1, and then coating an aluminum foil with a sheet to prepare a positive electrode sheet; a lithium plate is used as a negative electrode, a polypropylene porous membrane Celgard2400 is used as a diaphragm, an electrolyte is assembled into an experimental button battery with the model of CR2025 in a glove box filled with argon gas by using 1.0mol/L LiPF6-EC/DMC (volume ratio of 1:1), the experimental button battery is placed still for 12 hours and then is tested on a LAND CT2001A tester, the test voltage interval is 2V-4.8V, and the test temperature is 30 ℃.
Fig. 8 is a graph of the cycle curve of the CR2025 experimental button cell assembled by the composite lithium-rich manganese-based positive electrode material prepared in example 2 at 1C for 150 weeks, and it can be seen that at 1C rate, the charge-discharge cycle process is relatively stable, and in the first 100 weeks, the capacity decays slowly; after 100 weeks, the battery capacity generally tended to increase, and the capacity at 150 weeks was 161.6mAh/g, and the capacity retention rate was 84.35%.
Fig. 9 is a graph of cycling performance at 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, and 10C for CR2025 experimental coin cells assembled with the composite lithium-rich manganese-based cathode material prepared in example 2. As shown in fig. 9, the discharge capacity of the battery is relatively stable under the conditions of 0.1C, 0.2C, 0.5C, 1C, 2C, 5C, and 10C rates, and the battery still maintains a high capacity under the high-rate charge/discharge conditions of 1C, 2C, 5C, and 10C; wherein, the capacity under 1C can reach about 176mAh/g, the capacity under 2C can reach about 147mAh/g, the capacity under 5C can reach about 130mAh/g, the capacity attenuation is obvious as soon as possible under 10C, but the capacity can still reach about 90mAh/g after circulation for five weeks under 10C. This indicates that NaZr2(PO4)3The stability and the capacity under high multiplying power of the lithium-rich manganese-based positive electrode material are obviously improved by the coating layer.
Table 1 shows performance test data of the first discharge specific capacity at 1C, the discharge specific capacity after 150 cycles, and the capacity retention rate after 150 cycles of the CR2025 experimental button cell assembled by using the composite lithium-rich manganese-based positive electrode material prepared in examples 1 to 4 and the heat-treated lithium-rich manganese-based positive electrode material prepared in the comparative example. As can be seen from the data in Table 1, it is found that amorphous NaZr is not preferred2(PO4)3Coating layer, crystal NaZr2(PO4)3The coating layer is also amorphous and crystal composite NaZr2(PO4)3The capacity retention after 150 weeks cycling at 1C of the coating was higher than this value in the comparative example. Description of NaZr2(PO4)3The coating layer has the functions of stabilizing the structure and accelerating the lithium ion transmission, and the most obvious function is amorphous and crystalline composite NaZr2(PO4)3And the coating layer shows that the synergistic effect of the two structures is most beneficial to the intercalation and deintercalation of lithium ions under high rate, and can protect the body material structure from being corroded by electrolyte to the maximum extent.
TABLE 1
Figure BDA0001179179860000091
The present invention includes, but is not limited to, the above embodiments, and any equivalent substitutions or partial modifications made under the spirit and principle of the present invention should be considered within the scope of the present invention.

Claims (9)

1. A preparation method of a composite lithium-rich manganese-based positive electrode material is characterized by comprising the following steps: the steps of the method are as follows,
step 1, dissolving sodium salt, zirconium salt, phosphate and a complexing agent into a solvent, and uniformly mixing to obtain a coating solution;
step 2. mixing Li1.2Mn0.6Ni0.2O2Fully mixing the precursor with the coating solution, and evaporating the solvent to obtain a composite material precursor;
and 3, under a protective atmosphere, presintering the composite material precursor at the temperature of 200-300 ℃ for 2-3 h, calcining at the temperature of 600-700 ℃ for 5-6 h, and cooling to obtain the composite lithium-rich manganese-based anode material with the core-shell structure, wherein Li is1.2Mn0.6Ni0.2O2As a nuclear material, NaZr2(PO4)3Is a surface uniform coating layer;
the sodium salt is sodium carbonate, sodium hydroxide, sodium dihydrogen phosphate, sodium nitrate, sodium bicarbonate, sodium chloride or sodium acetate;
the zirconium salt is zirconium carbonate or zirconium nitrate;
the phosphate is diammonium hydrogen phosphate, ammonium dihydrogen phosphate or sodium dihydrogen phosphate;
the complexing agent is citric acid, ammonium oxalate, ammonium citrate, polyvinylpyrrolidone, diethanolamine, triethanolamine or disodium ethylene diamine tetraacetate;
the solvent is HCl aqueous solution, NaCl aqueous solution or water;
the gas of the protective atmosphere is argon or nitrogen.
2. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: the coating solution in the step 1 is prepared by the following method:
step a, respectively dissolving sodium salt, zirconium salt, phosphate and a complexing agent in a solvent, and uniformly mixing to respectively obtain a sodium salt solution, a zirconium salt solution, a phosphate solution and a complexing agent solution;
and b, adding the sodium salt solution, the zirconium salt solution and the phosphate solution into the complexing agent solution, and uniformly mixing to obtain a coating solution.
3. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 2, characterized in that: in the step a, the conditions for preparing the sodium salt solution, the zirconium salt solution and the phosphate solution are as follows: the temperature is 45-80 ℃, the stirring time is 0.5-1 h, and the stirring speed is 100-500 rmp;
the conditions for preparing the complexing agent solution are as follows: the temperature is 30-50 ℃, the stirring time is 5-8 h, and the stirring speed is 100-500 rmp.
4. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 2, characterized in that: in the step b, the solution is uniformly mixed under the following conditions: the temperature is 30-50 ℃, the stirring time is 0.5-2 h, and the stirring speed is 100-500 rmp.
5. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: in the coating solution prepared in the step 1, the mole number of sodium element is as follows: molar number of zirconium element: the mole number of the phosphorus element is 1-1.5: 2: 3-3.5; prepared NaZr2(PO4)3The mass ratio of the coating layer to the complexing agent is 1: 10-30.
6. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: in the prepared composite lithium-rich manganese-based cathode material, Li1.2Mn0.6Ni0.2O2Mass of (2) and NaZr2(PO4)3The mass ratio of the coating layer is 1: 0.01-0.3.
7. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: in step 2, the conditions for evaporating the solvent are as follows: the temperature is 60-90 ℃, the stirring time is 6-8 h, and the stirring speed is 100-1000 rmp.
8. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: the Li1.2Mn0.6Ni0.2O2The particle diameter of (A) is 0.1 to 0.4. mu.m.
9. The preparation method of the composite lithium-rich manganese-based positive electrode material according to claim 1, characterized in that: NaZr2(PO4)3The thickness of the coating layer is 2 nm-10 nm.
CN201611147525.3A 2016-12-13 2016-12-13 Composite lithium-rich manganese-based positive electrode material and preparation method thereof Active CN106711412B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201611147525.3A CN106711412B (en) 2016-12-13 2016-12-13 Composite lithium-rich manganese-based positive electrode material and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201611147525.3A CN106711412B (en) 2016-12-13 2016-12-13 Composite lithium-rich manganese-based positive electrode material and preparation method thereof

Publications (2)

Publication Number Publication Date
CN106711412A CN106711412A (en) 2017-05-24
CN106711412B true CN106711412B (en) 2020-03-31

Family

ID=58935702

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201611147525.3A Active CN106711412B (en) 2016-12-13 2016-12-13 Composite lithium-rich manganese-based positive electrode material and preparation method thereof

Country Status (1)

Country Link
CN (1) CN106711412B (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109888208A (en) * 2019-01-25 2019-06-14 高点(深圳)科技有限公司 Anode material for lithium-ion batteries and its preparation method and application
CN109980202A (en) * 2019-03-26 2019-07-05 湖北锂诺新能源科技有限公司 The preparation method of titanium doped and titanium phosphate sodium cladding fluorosulfuric acid ferrous iron lithium anode material
CN111435747B (en) * 2020-01-17 2022-11-22 蜂巢能源科技有限公司 Cobalt-free layered cathode material, preparation method thereof and lithium ion battery
CN114538533B (en) * 2022-01-25 2023-10-27 合肥融捷能源材料有限公司 Nickel cobalt lithium manganate and preparation method and application thereof
CN116936776B (en) * 2023-09-15 2024-03-19 宁德时代新能源科技股份有限公司 Positive electrode active material, pole piece, battery and electric equipment

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103943854A (en) * 2014-03-26 2014-07-23 长沙矿冶研究院有限责任公司 Surface-coated modified lithium ion battery cathode material and preparation method thereof

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016175554A1 (en) * 2015-04-30 2016-11-03 주식회사 엘지화학 Cathode active material for lithium secondary battery, manufacturing method therefor, and lithium secondary battery including same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103943854A (en) * 2014-03-26 2014-07-23 长沙矿冶研究院有限责任公司 Surface-coated modified lithium ion battery cathode material and preparation method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Sun-Ho Kang等.Enhancing the rate capability of high capacity xLi2MnO3 •(1-x)LiMO2 (M = Mn,Ni, Co) electrodes by Li-Ni-PO4 treatment.《Electrochemistry Communications》.2009,第11卷第748–751页. *

Also Published As

Publication number Publication date
CN106711412A (en) 2017-05-24

Similar Documents

Publication Publication Date Title
KR102682051B1 (en) Lithium manganese iron phosphate precursor, lithium manganese iron phosphate anode material and manufacturing method thereof, electrode material, electrode and lithium ion battery
CN106711412B (en) Composite lithium-rich manganese-based positive electrode material and preparation method thereof
CN115472819A (en) Positive active material, positive pole piece and sodium ion battery
CN108598394B (en) Carbon-coated titanium manganese phosphate sodium microspheres and preparation method and application thereof
CN109817904B (en) High-voltage long-cycle high-nickel single crystal positive electrode material and preparation method and application thereof
CN112551540B (en) Silicon-aluminum molecular sieve additive for lithium-rich manganese-based positive electrode and preparation method and application thereof
WO2016176928A1 (en) Negative electrode material, preparation method therefor, and lithium-ion secondary battery using the negative electrode material
CN105576231A (en) High-voltage lithium oil battery positive electrode material with spinel structure and preparation method of high-voltage lithium oil battery positive electrode material
CN108091854A (en) A kind of high-voltage spinel type anode material for lithium-ion batteries of Anion-cation multiple dope and preparation method thereof
CN112151773A (en) Positive active material, preparation method thereof and lithium battery
WO2020098275A1 (en) Sio2-covered ternary positive electrode material and preparation method therefor
CN107394156A (en) A kind of method of modifying and its modified anode material of the lithium-rich manganese-based anode material for lithium-ion batteries based on organic matter ammoniacal liquor
CN110098387B (en) Lithium phosphate and conductive carbon material coated ternary cathode material and preparation method and application thereof
CN103094567A (en) Anode material of lithium fast ionic conductor compounded lithium battery and preparation method of anode material
CN114927667B (en) Positive electrode active material, preparation method thereof, positive electrode sheet and lithium ion secondary battery
CN108598411B (en) Nitrogen-doped carbon-coated tin oxide/iron oxide composite material, preparation method thereof and lithium battery material
CN110931733B (en) Surface manganese doping and Li-Mn-PO4Coated high-nickel positive electrode material and preparation method and application thereof
CN111211362B (en) Lithium-supplementing washing liquid and application thereof, high-nickel multi-element positive electrode material and preparation method thereof
CN112768664A (en) Preparation method of ruthenium-doped lithium iron phosphate composite positive electrode material
CN113078315A (en) Lithium-rich manganese-based positive electrode material coated by double conductive layers and preparation method and application thereof
CN112421000A (en) Double-coated lithium-manganese-rich base material and preparation method and application thereof
CN105185969B (en) A kind of positive electrode and preparation method thereof
CN109860543B (en) Method for preparing chromium-doped nickel-cobalt lithium aluminate gradient cathode material for lithium battery
CN107946567B (en) Lithium ion battery anode material with three-dimensional polyacid coating layer of ion and electron conductor
CN104332628A (en) Preparation method and lithium ion battery of lithium ion battery positive material

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant