CN116565184B - Positive electrode material, preparation method thereof, positive electrode plate and lithium battery - Google Patents
Positive electrode material, preparation method thereof, positive electrode plate and lithium battery Download PDFInfo
- Publication number
- CN116565184B CN116565184B CN202310847516.9A CN202310847516A CN116565184B CN 116565184 B CN116565184 B CN 116565184B CN 202310847516 A CN202310847516 A CN 202310847516A CN 116565184 B CN116565184 B CN 116565184B
- Authority
- CN
- China
- Prior art keywords
- lithium
- positive electrode
- manganese
- electrode material
- coating layer
- 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
Links
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 title claims abstract description 238
- 229910052744 lithium Inorganic materials 0.000 title claims abstract description 238
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 147
- 238000002360 preparation method Methods 0.000 title abstract description 18
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims abstract description 257
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 204
- 239000011572 manganese Substances 0.000 claims abstract description 204
- 239000011247 coating layer Substances 0.000 claims abstract description 125
- 239000000463 material Substances 0.000 claims abstract description 80
- 229910052751 metal Inorganic materials 0.000 claims abstract description 64
- 239000002184 metal Substances 0.000 claims abstract description 64
- 239000004005 microsphere Substances 0.000 claims abstract description 42
- 239000002243 precursor Substances 0.000 claims description 70
- 238000006243 chemical reaction Methods 0.000 claims description 61
- 239000000243 solution Substances 0.000 claims description 45
- 239000000126 substance Substances 0.000 claims description 41
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 33
- 239000012266 salt solution Substances 0.000 claims description 33
- 239000002245 particle Substances 0.000 claims description 27
- 238000001354 calcination Methods 0.000 claims description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 22
- 229910052799 carbon Inorganic materials 0.000 claims description 22
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims description 20
- 239000011248 coating agent Substances 0.000 claims description 20
- 238000000576 coating method Methods 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 20
- 150000002696 manganese Chemical class 0.000 claims description 19
- 150000003839 salts Chemical class 0.000 claims description 19
- 238000002156 mixing Methods 0.000 claims description 18
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 18
- 229940099596 manganese sulfate Drugs 0.000 claims description 17
- 239000011702 manganese sulphate Substances 0.000 claims description 17
- 235000007079 manganese sulphate Nutrition 0.000 claims description 17
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 claims description 17
- 238000001556 precipitation Methods 0.000 claims description 17
- 239000008139 complexing agent Substances 0.000 claims description 12
- 229910052759 nickel Inorganic materials 0.000 claims description 12
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 11
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 11
- 239000013078 crystal Substances 0.000 claims description 10
- 238000001035 drying Methods 0.000 claims description 9
- 238000001694 spray drying Methods 0.000 claims description 9
- 238000005253 cladding Methods 0.000 claims description 8
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 7
- 229930006000 Sucrose Natural products 0.000 claims description 7
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 claims description 7
- 239000005720 sucrose Substances 0.000 claims description 7
- 150000001868 cobalt Chemical class 0.000 claims description 6
- 150000002815 nickel Chemical class 0.000 claims description 6
- 125000000185 sucrose group Chemical group 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims 3
- 239000010410 layer Substances 0.000 description 30
- 239000003792 electrolyte Substances 0.000 description 25
- KLARSDUHONHPRF-UHFFFAOYSA-N [Li].[Mn] Chemical compound [Li].[Mn] KLARSDUHONHPRF-UHFFFAOYSA-N 0.000 description 17
- 230000000052 comparative effect Effects 0.000 description 14
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 11
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 11
- 239000010406 cathode material Substances 0.000 description 10
- 239000010405 anode material Substances 0.000 description 9
- 238000003756 stirring Methods 0.000 description 9
- 229910001416 lithium ion Inorganic materials 0.000 description 8
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 8
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 6
- 125000004122 cyclic group Chemical group 0.000 description 6
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 6
- 229910052808 lithium carbonate Inorganic materials 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- 229910013290 LiNiO 2 Inorganic materials 0.000 description 5
- 239000011149 active material Substances 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 5
- 238000009826 distribution Methods 0.000 description 5
- 238000001000 micrograph Methods 0.000 description 5
- 238000013508 migration Methods 0.000 description 5
- 230000005012 migration Effects 0.000 description 5
- 238000011056 performance test Methods 0.000 description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 4
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 230000008595 infiltration Effects 0.000 description 4
- 238000001764 infiltration Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000011889 copper foil Substances 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000003487 electrochemical reaction Methods 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 230000002195 synergetic effect Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000002001 electrolyte material Substances 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 230000002349 favourable effect Effects 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- -1 lithium hexafluorophosphate Chemical compound 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 230000005855 radiation Effects 0.000 description 2
- OIFBSDVPJOWBCH-UHFFFAOYSA-N Diethyl carbonate Chemical compound CCOC(=O)OCC OIFBSDVPJOWBCH-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- DPXJVFZANSGRMM-UHFFFAOYSA-N acetic acid;2,3,4,5,6-pentahydroxyhexanal;sodium Chemical compound [Na].CC(O)=O.OCC(O)C(O)C(O)C(O)C=O DPXJVFZANSGRMM-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910021383 artificial graphite Inorganic materials 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 239000006182 cathode active material Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 239000011258 core-shell material Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000009831 deintercalation Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000007765 extrusion coating Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000007561 laser diffraction method Methods 0.000 description 1
- 238000002386 leaching Methods 0.000 description 1
- KBJMLQFLOWQJNF-UHFFFAOYSA-N nickel(ii) nitrate Chemical compound [Ni+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O KBJMLQFLOWQJNF-UHFFFAOYSA-N 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 235000019812 sodium carboxymethyl cellulose Nutrition 0.000 description 1
- 229920001027 sodium carboxymethylcellulose Polymers 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
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
- H01M4/13—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
- H01M4/133—Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
-
- 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
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
- H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Composite Materials (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention relates to the technical field of batteries, in particular to a positive electrode material, a preparation method thereof, a positive electrode plate and a lithium battery. The positive electrode material includes: the inner core is a microsphere with a cavity; the first lithium-rich manganese-based coating layer is coated on the periphery of the inner core; the second lithium-rich manganese-based coating layer is coated on the periphery of the first lithium-rich manganese-based coating layer; the content of the metal manganese element in the second lithium-rich manganese-based coating layer is lower than that in the first lithium-rich manganese-based coating layer. The novel positive electrode material structure not only has good structural stability, but also can exert higher material utilization rate and can ensure higher gram capacity level.
Description
Technical Field
The invention relates to the technical field of batteries, in particular to a positive electrode material, a preparation method thereof, a positive electrode plate and a lithium battery.
Background
With the development of battery technology, lithium batteries are increasingly pursuing higher energy densities. Although lithium iron phosphate is a cathode active material which is commonly used in lithium batteries in the market at present, the theoretical gram capacity of the lithium iron phosphate is low, and the lithium iron phosphate is difficult to meet the requirement of higher energy density.
The lithium-rich manganese-based material has higher theoretical gram capacity and is suitable for being used as a positive electrode material of a lithium battery. However, when the lithium-rich manganese-based material is used as a positive electrode material, there are also many problems including: the lithium battery has obvious metal manganese dissolution in the cyclic charge and discharge process, so that the structural stability of the lithium-rich manganese-based material is poor, and the cyclic performance of the lithium battery is deteriorated; and the material in the center part of the current lithium-rich manganese-based material is difficult to participate in electrochemical reaction in the charge and discharge process of the lithium battery, and the material utilization efficiency is insufficient. That is, it is difficult to satisfy the current lithium-rich manganese-based materials with higher gram capacity, better structural stability, and higher material utilization.
Disclosure of Invention
In order to solve the technical problems, the application discloses a positive electrode material and a preparation method thereof, a positive electrode plate and a lithium battery, and aims to solve the problem that the existing positive electrode material is difficult to simultaneously meet high gram capacity, high structural stability and high material utilization rate.
In a first aspect, an embodiment of the present application provides a positive electrode material including:
the inner core is a microsphere with a cavity;
the first lithium-rich manganese-based coating layer is coated on the periphery of the inner core;
The second lithium-rich manganese-based coating layer is coated on the periphery of the first lithium-rich manganese-based coating layer;
the content of the metal manganese element in the second lithium-rich manganese-based coating layer is lower than that in the first lithium-rich manganese-based coating layer.
Further, the chemical formula of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer is as follows: x is x 1 Li 2 MnO 3 • (1－x 1 )LiM 1 O 2 Wherein, x is more than or equal to 0.3 1 <1，M 1 Is Ni or Co; and/or the number of the groups of groups,
the chemical formula of the lithium-rich manganese-based material in the second lithium-rich manganese-based coating layer is as follows: x is x 2 Li 2 MnO 3 • (1－x 2 )LiM 2 O 2 Wherein 0 is<x 2 <0.5，M 2 Is Ni or Co.
Further, the content of the metal manganese element in the first lithium-rich manganese-based coating layer is 26% -46.9%, and the content of the metal manganese element in the second lithium-rich manganese-based coating layer is more than 0% and less than 26%.
Further, the particle size Dv50 of the positive electrode material is 8-12 mu m; and/or, I of the positive electrode material 003 /I 104 Greater than or equal to 1.3, wherein the I 003 The peak intensity of the diffraction peak of the 003 crystal face of the positive electrode material is the I 104 The peak intensity of the diffraction peak of the 104 crystal face of the positive electrode material.
Further, the second lithium-rich manganese-based cladding layer has a thickness of greater than or equal to 2 microns.
In a second aspect, an embodiment of the present application provides a method for preparing a positive electrode material, where the positive electrode material is the positive electrode material according to the first aspect, and the method for preparing a positive electrode material includes the following steps:
preparing the core: treating a carbon source by adopting a spray drying method to prepare a carbon microsphere precursor, and roasting the carbon microsphere precursor to form the inner core, wherein the inner core is a microsphere with a cavity;
preparing a first precursor: mixing the inner core, a first mixed metal salt solution with soluble manganese salt and M salt, a first precipitant solution and a first complexing agent solution to form a first reaction system, and carrying out precipitation and combination reaction on the first reaction system to obtain the first precursor; wherein the M salt in the first mixed metal salt solution is nickel salt and/or cobalt salt;
forming a first cladding material: mixing and calcining the first precursor and a first lithium source to coat the outer periphery of the inner core with the first lithium-rich manganese-based coating layer to form the first coating material;
preparing a second precursor: mixing the first coating material, a second mixed metal salt solution with soluble manganese salt and M salt, a second precipitant solution and a second complexing agent solution to form a second reaction system, and carrying out precipitation and combination reaction on the second reaction system to obtain a second precursor; wherein the M salt in the two mixed metal salt solutions is nickel salt and/or cobalt salt;
Forming the positive electrode material: and mixing and calcining the second precursor and a second lithium source to enable the periphery of the first lithium-rich manganese-based coating layer to be coated with a second lithium-rich manganese-based coating layer, and controlling the content of metal manganese elements in the second lithium-rich manganese-based coating layer to be lower than that in the first lithium-rich manganese-based coating layer to obtain the positive electrode material.
Further, in the step of preparing the first precursor, the ratio of the amount of the substance of the manganese element in the soluble manganese salt to the amount of the substance of the M element in the M salt in the first mixed metal salt solution is x 1 :(1－x 1 ) X is more than or equal to 0.3 1 <1, a step of; and/or the number of the groups of groups,
in the step of forming the first coating material, the ratio of the amount of the metal manganese element in the first precursor to the amount of the substance of the lithium element in the first lithium source is x 1 :(x 1 +1)，0.3≤x 1 <1, a step of; and/or the number of the groups of groups,
in the step of preparing the second precursor, the ratio of the amount of the substance of the manganese element in the soluble manganese salt to the amount of the substance of the M element in the M salt in the second mixed metal salt solution is x 2 :(1－x 2 ) And 0 is<x 2 <0.5; and/or the number of the groups of groups,
in the step of forming the positive electrode material, the ratio of the amount of the metal manganese element in the second precursor to the amount of the substance of the lithium element in the second lithium source is x 2 :(x 2 +1)，0<x 2 <0.5; and/or the number of the groups of groups,
the soluble manganese salt in the first mixed metal salt solution comprises at least one of manganese sulfate or manganese nitrate, the first precipitant solution comprises at least one of sodium hydroxide solution or potassium hydroxide solution, and the first complexing agent solution is an ammonia water solution; and/or the number of the groups of groups,
the soluble manganese salt in the second mixed metal salt solution comprises at least one of manganese sulfate or manganese nitrate, the second precipitant solution comprises at least one of sodium hydroxide solution or potassium hydroxide solution, and the second complexing agent solution is an ammonia water solution; and/or the number of the groups of groups,
the carbon source is sucrose.
Further, in the step of preparing the inner core, a spray drying method is adopted, the drying temperature is 140-160 ℃, the roasting temperature is 440-460 ℃, and the roasting time is 2-4 hours; and/or the number of the groups of groups,
in the step of preparing the first precursor, the conditions for performing the precipitation and chemical combination reaction include: reacting the first reaction system for 3-5 hours under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃; and/or the number of the groups of groups,
in the step of forming the first cladding material, the calcining temperature is 300-600 ℃ and the calcining time is 5-10 hours; and/or the number of the groups of groups,
in the step of preparing the second precursor, the conditions for performing the precipitation-chemical reaction include: reacting the second reaction system for 3-5 hours under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃; and/or the number of the groups of groups,
In the step of forming the positive electrode material, the calcination temperature is 300-600 ℃ and the calcination time is 5-10 h.
In a third aspect, an embodiment of the present application provides a positive electrode sheet, where the positive electrode sheet includes the positive electrode material according to the first aspect, or the positive electrode sheet includes the positive electrode material prepared by the preparation method according to the second aspect.
In a fourth aspect, an embodiment of the present application provides a lithium battery, where the lithium battery includes the positive electrode material according to the first aspect, or the lithium battery includes the positive electrode material prepared by the preparation method according to the second aspect, or the lithium battery includes the positive electrode sheet according to the third aspect.
Compared with the prior art, the application has the beneficial effects that:
the embodiment of the application provides a novel positive electrode material structure, wherein microspheres with cavities are arranged in the positive electrode material, and two layers of lithium-rich manganese-based material coating layers with different metal manganese elements are sequentially coated on the peripheries of the microspheres. When the positive electrode material is used for a lithium battery, particularly a cylindrical lithium battery, the structural performance is stable, and the requirement of higher energy density can be met.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a particle size distribution diagram of a positive electrode material of example 1;
FIG. 2 is a scanning electron microscope image of the surface of the positive electrode material particles of example 1;
FIG. 3 is a scanning electron microscope image of a cross section of a particle of the positive electrode material of example 1;
FIG. 4 is an XRD pattern for the positive electrode material of example 1;
fig. 5 is a scanning electron microscope image of a particle cross section of the positive electrode material of example 3.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate an azimuth or a positional relationship based on that shown in the drawings. These terms are only used to better describe the present invention and its embodiments and are not intended to limit the scope of the indicated devices, elements or components to the particular orientations or to configure and operate in the particular orientations.
Also, some of the terms described above may be used to indicate other meanings in addition to orientation or positional relationships, for example, the term "upper" may also be used to indicate some sort of attachment or connection in some cases. The specific meaning of these terms in the present invention will be understood by those of ordinary skill in the art according to the specific circumstances.
Furthermore, the terms "mounted," "configured," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; may be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements, or components. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
Furthermore, the terms "first," "second," and the like, are used primarily to distinguish between different devices, elements, or components (the particular species and configurations may be the same or different), and are not used to indicate or imply the relative importance and number of devices, elements, or components indicated. Unless otherwise indicated, the meaning of "a plurality" is two or more.
The technical scheme of the present invention will be described below with reference to examples and drawings.
Lithium iron phosphate is a relatively common positive electrode material of lithium batteries on the market at present, but the theoretical gram capacity of the lithium iron phosphate is only 170 mAh/g, and the lithium iron phosphate belongs to a relatively low level in the positive electrode material. When lithium iron phosphate is used in lithium batteries, especially in cylindrical lithium batteries, it has been difficult to meet the increasingly higher energy density pursuit. Therefore, it is necessary to develop a few positive electrode materials with higher theoretical gram capacity, and the positive electrode materials have industrial application prospect, and can meet the actual industrial requirements.
The lithium-rich manganese-based material is a material with higher theoretical gram capacity (theoretical gram capacity is more than 350 mAh/g), has the advantages of high voltage, high energy density and the like, and is suitable for being developed as a cathode material for replacing lithium iron phosphate. However, the lithium-rich manganese-based material has more defects to be overcome: the lithium-rich manganese-based material can be dissolved out of metal manganese in the cyclic charge and discharge process, so that the structural stability of the lithium-rich manganese-based material is poor, and the cyclic performance of the lithium battery is continuously deteriorated; moreover, the particle size of the existing lithium-rich manganese-based material is usually larger (generally larger than 10 micrometers), and the central part of the lithium-rich manganese-based material is difficult to contact with electrolyte in the charge and discharge process of a lithium battery, so that the lithium-rich manganese-based material is difficult to participate in electrochemical reaction, and the utilization rate of the lithium-rich manganese-based material is low, so that the lithium-rich manganese-based material cannot fully play a role.
According to the analysis, the existing lithium-rich manganese-based material has the problems of relatively poor structural stability and relatively low material utilization rate, so that the existing lithium-rich manganese-based material is relatively difficult to meet the industrial requirements of the lithium battery anode material. In other words, there is a need to improve the current lithium-rich manganese-based materials to obtain a lithium-rich manganese-based material that has a high gram capacity, good structural stability, and full utilization of the material.
Based on the analysis, the embodiment of the application provides a positive electrode material, a preparation method thereof, a positive electrode plate and a lithium battery, so as to solve the problems.
In a first aspect, the present application provides a positive electrode material comprising:
the inner core is a microsphere with a cavity;
the first lithium-rich manganese-based coating layer is coated on the periphery of the inner core;
the second lithium-rich manganese-based coating layer is coated on the periphery of the first lithium-rich manganese-based coating layer;
the content of the metal manganese element in the second lithium-rich manganese-based coating layer is lower than that in the first lithium-rich manganese-based coating layer.
The inner core is a microsphere with a cavity, for example, the inner core can be a carbon microsphere, and the microstructure of the inner core has the characteristics of the cavity and the porosity, so that more space is provided for infiltration of electrolyte and the electrolyte is in more full contact with the lithium-rich manganese-based material when the outer layer of the inner core is coated with two lithium-rich manganese-based coating layers with different gradient manganese contents. The first lithium-rich manganese-based coating layer is a lithium-rich manganese-based material, and the first lithium-rich manganese-based coating layer is coated on the outer periphery of the inner core and is to be understood in a broad sense, and the first lithium-rich manganese-based coating layer comprises a layer of lithium-rich manganese-based material coated on the outer surface of the inner core and also comprises a part of lithium-rich manganese-based material embedded into pores of the inner core due to the porous structure characteristic of the inner core.
The embodiment of the application provides a novel positive electrode material structure, wherein microspheres with cavities are arranged in the positive electrode material, and two layers of lithium-rich manganese-based material coating layers with different metal manganese elements are sequentially coated on the peripheries of the microspheres. When the positive electrode material is used for a lithium battery, particularly a cylindrical lithium battery, the structural performance is stable, and the requirement of higher energy density can be met.
The inner core of the positive electrode material is a microsphere with a cavity, and a first lithium-rich manganese-based coating layer with higher manganese content and a second lithium-rich manganese-based coating layer with lower manganese content are sequentially coated outside the microsphere. In this way, in the process that the electrolyte is contacted with the positive electrode material, the electrolyte is firstly contacted with the second lithium-rich manganese-based coating layer of the positive electrode material, and the content of the metal manganese element in the coating layer is lower than that of the first lithium-rich manganese-based coating layer, so that the corrosion degree of the electrolyte to the metal manganese element in the second lithium-rich manganese-based coating layer is slight, and the dissolution of the metal manganese element can be effectively reduced.
On the basis, electrolyte gradually permeates into the first lithium-rich manganese-based coating layer and the microsphere with the cavity inside from the second lithium-rich manganese-based coating layer, on one hand, the inner core has the cavity and porous structural characteristics, so that the infiltration channel of the electrolyte is increased, lithium ions in the center part of the positive electrode material can participate in electrochemical reaction, the effective utilization rate of the positive electrode material is improved, and the electrochemical performance of the lithium battery is improved. On the other hand, although the cavity and pore structure of the inner core can have a certain influence on the gram-capacity of the lithium-rich manganese-based material, the application adopts the structure of the microsphere and the first lithium-rich manganese-based coating layer with high manganese content for outer coating, and the gram-capacity of the positive electrode material is improved by improving the content of the metal manganese element in the first lithium-rich manganese-based coating layer, so that the influence of the microsphere on the gram-capacity is solved, and the positive electrode material is ensured to have higher gram-capacity.
Moreover, because the microspheres with cavities and the first lithium-manganese-rich base coating layer with high manganese content are also coated with the second lithium-manganese-rich base coating layer with low manganese content, the effect of the second lithium-manganese-rich base coating layer for reducing the dissolution of manganese elements is equivalent to that of enabling the second lithium-manganese-rich base coating layer to serve as a protective layer of the first lithium-manganese-rich base coating layer, the situation that a large amount of manganese elements in the first lithium-manganese-rich base coating layer are dissolved out can be avoided, and therefore the utilization rate of the anode material is improved, the higher gram capacity is ensured, and meanwhile, the structural stability of the anode material is also improved on the whole.
From the above, it can be seen that, in the embodiment of the present application, by arranging the microsphere with a cavity, the first lithium-manganese-rich coating layer with high manganese content and the second lithium-manganese-rich coating layer with low manganese content, which are sequentially coated on the outer periphery of the core, the novel lithium-manganese-rich anode material can simultaneously meet the requirements of higher structural stability, better material utilization rate and higher gram capacity of the anode material.
Further, in an embodiment of the present application, the chemical formula of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer is: x is x 1 Li 2 MnO 3 • (1－x 1 )LiM 1 O 2 Wherein, x is more than or equal to 0.3 1 <1，M 1 Is Ni or Co. X is more than or equal to 0.3 1 <1 includes any point within the range of values, e.g., x 1 0.5, 0.6, 0.7, 0.8, 0.9 or 0.95.
Further, the chemical formula of the lithium-rich manganese-based material in the second lithium-rich manganese-based coating layer is as follows: x is x 2 Li 2 MnO 3 • (1－x 2 )LiM 2 O 2 Wherein 0 is<x 2 <0.5，M 2 Is Ni or Co.0<x 2 <0.5 includes any point within the range of values, e.g., x 2 0.05, 0.1, 0.2, 0.3, 0.4 or 0.45.
In the embodiment of the application, two layers of lithium-rich manganese-based materials with different manganese contents are sequentially coated outside the microsphere with the cavity, wherein the chemical formula of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer positioned in the inner layer is x 1 Li 2 MnO 3 • (1－x 1 )LiM 1 O 2 ，0.3≤x 1 <1, the chemical formula of the lithium-rich manganese-based material in the second lithium-rich manganese-based coating layer positioned on the outer layer is x 2 Li 2 MnO 3 • (1－x 2 )LiM 1 O 2 ，0<x 2 <0.5。
Wherein x in the second lithium-rich manganese-based coating layer 2 Is smaller, indicating a lower content of metallic manganese element in the layer, x in the first lithium-rich manganese-based coating layer 1 The range of the lithium-manganese-rich electrolyte is larger, which shows that the content of metal manganese in the lithium-manganese-rich electrolyte layer is higher, and the first lithium-manganese-rich electrolyte layer is used as a transition layer between the second lithium-manganese-rich electrolyte layer and the inner core, so that on one hand, the corrosion impact of the electrolyte to the manganese element of the lithium-manganese-rich electrolyte material in the positive electrode material can be weakened through the gradient difference of the manganese element content in the inner and outer lithium-manganese-rich electrolyte layers, so that more manganese element in the lithium-manganese-rich electrolyte material is reserved, the structural stability of the positive electrode material is improved, and the gram capacity of a high level is kept; on the other hand, the first lithium-rich manganese-based coating layer with higher manganese content is complementary with the porous microspheres with cavities, so that the infiltration channels of the electrolyte are enriched, the high-level gram capacity is further maintained, and the influence on the lithium-rich manganese-based gram capacity caused by the fact that the porous microspheres occupy the center of the anode material is reduced.
Further, the content of the metal manganese element in the first lithium-rich manganese-based coating layer is 26% -46.9%, and the content of the metal manganese element in the second lithium-rich manganese-based coating layer is more than 0% and less than 26%. The content of the metal manganese element in the first lithium-rich manganese-based coating layer is 26% -46.9%, including any point value in the numerical range, for example, the content of the metal manganese element in the first lithium-rich manganese-based coating layer is 26%, 28%, 30%, 32%, 35%, 38%, 40%, 42%, 45%, 46% or 46.9%. It will be appreciated that the content of the above metal manganese element refers to mass percent.
When the content of metal manganese in the inner and outer lithium-rich manganese-based coating layers is respectively in the above range, not only can the manganese content gradient with low manganese content in the outer layer and high manganese content in the inner layer be realized, but also the influence of the electrolyte on the elution of manganese element is buffered by the second lithium-rich manganese-based coating layer with low manganese content in the outer layer, so that the elution of a large amount of manganese element in the first lithium-rich manganese-based coating layer with high manganese content in the inner layer is avoided, and the structural stability of the anode material and the high gram capacity level of the lithium-rich manganese base are ensured; and the synergistic effect between the first lithium-rich manganese-based coating layer with high inner layer manganese content and the inner core in the aspects of gram capacity of the positive electrode material and infiltration sufficiency of electrolyte in the positive electrode material can be realized, so that the gram capacity of a higher level can be kept, the reaction degree of the electrolyte and the positive electrode material can be improved, and the utilization rate of the positive electrode material can be improved.
Further, the particle diameter Dv50 of the positive electrode material is 8-12 mu m. Wherein the particle diameter Dv50 of the positive electrode material is 8 μm to 12 μm, including any point value within the particle diameter range, for example, the particle diameter Dv50 of the positive electrode material is 8 μm, 9 μm, 10 μm, 11 μm or 12 μm.
The particle diameter Dv50 of the positive electrode material falling within the above range is advantageous in maintaining the structural stability of the positive electrode material while ensuring good electron transport ability. When the particle diameter Dv50 is 8-12 mu m, the two lithium-rich manganese-based coating layers can have good coating stability, and the condition that the inner layer is difficult to form an effective coating layer is avoided; meanwhile, lithium ions also have good deintercalation capability and proper migration paths under the condition of the particle size range, so that the positive electrode material is ensured to have smaller impedance and good kinetic performance.
Further, I of the positive electrode material 003 /I 104 Greater than or equal to 1.3, wherein the I 003 The peak intensity of the diffraction peak of the 003 crystal face of the positive electrode material is the I 104 The peak intensity of the diffraction peak of the 104 crystal face of the positive electrode material. Wherein I of the positive electrode material 003 /I 104 Greater than or equal to 1.3 includes any point within the ratio range, e.g., I for the positive electrode material 003 /I 104 1.3, 1.4, 1.456, 1.5, 1.55, 1.6, 1.65, or 1.7.
I of cathode Material 003 /I 104 When the positive electrode material is more than or equal to 1.3, the positive electrode material is a lithium-rich manganese base material crystal phase, the purity is higher, the positive electrode material has a better layered structure, and the cation mixing degree is lower. The crystal face corresponding to the peak is more favorable for migration of lithium ions, so that the dynamic performance of the positive electrode material is improved.
Further, in the embodiment of the present application, the thickness of the second lithium-rich manganese-based coating layer is greater than or equal to 2 micrometers. Wherein a thickness of the second lithium-rich manganese-based coating layer of greater than or equal to 2 microns includes any point within the range of values, such as a thickness of the second lithium-rich manganese-based coating layer of 2 microns, 3 microns, 4 microns, 5 microns, 6 microns, or 7 microns. Preferably, the thickness of the second lithium-rich manganese-based coating layer is 3-5 microns. The second lithium-rich manganese-based coating layer with the thickness is beneficial to providing a more stable coating effect and reducing the corrosion dissolution degree of the electrolyte to manganese element in the lithium-rich manganese-based material.
In a second aspect, an embodiment of the present application further provides a method for preparing the positive electrode material according to the first aspect, where the method includes the following steps:
Preparing the core: treating a carbon source by adopting a spray drying method to prepare a carbon microsphere precursor, and roasting the carbon microsphere precursor to form the inner core, wherein the inner core is a microsphere with a cavity;
preparing a first precursor: mixing the inner core, a first mixed metal salt solution with soluble manganese salt and M salt, a first precipitant solution and a first complexing agent solution to form a first reaction system, and carrying out precipitation and combination reaction on the first reaction system to obtain the first precursor; wherein the M salt in the first mixed metal salt solution is nickel salt and/or cobalt salt;
forming a first cladding material: mixing and calcining the first precursor and a first lithium source to coat the outer periphery of the inner core with the first lithium-rich manganese-based coating layer to form the first coating material;
preparing a second precursor: mixing the first coating material, a second mixed metal salt solution with soluble manganese salt and M salt, a second precipitant solution and a second complexing agent solution to form a second reaction system, and carrying out precipitation and combination reaction on the second reaction system to obtain a second precursor; wherein the M salt in the two mixed metal salt solutions is nickel salt and/or cobalt salt;
Forming the positive electrode material: and mixing and calcining the second precursor and a second lithium source to enable the periphery of the first lithium-rich manganese-based coating layer to be coated with a second lithium-rich manganese-based coating layer, and controlling the content of metal manganese elements in the second lithium-rich manganese-based coating layer to be lower than that in the first lithium-rich manganese-based coating layer to obtain the positive electrode material.
According to the embodiment of the application, a carbon source is treated by adopting a means of combining spray drying and roasting to obtain a core of the anode material, so that the core has the structural characteristics of a hollow and porous carbon microsphere; then, a precursor of the lithium-rich manganese-based material is prepared by combining a twice precipitation combination reaction and high-temperature roasting, and then the precursor and a lithium source are mixed and roasted, so that a first lithium-rich manganese-based coating layer and a second lithium-rich manganese-based coating layer are sequentially formed outside the inner core. On the basis of combining the precipitation and chemical combination reaction with the roasting means, the application can better control the content gradient of the manganese element in the first lithium-rich manganese-based coating layer and the second lithium-rich manganese-based coating layer by only adjusting the mass ratio of the manganese element in the soluble manganese salt and the M element in the M salt in the mixed metal salt solution for carrying out the precipitation and chemical combination reaction, thereby obtaining the anode material with less manganese element leaching amount, high lithium-rich manganese-based capacity and better electrochemical performance.
Further, in the step of preparing the inner core, a spray drying method is adopted, the drying temperature is 140-160 ℃, the roasting temperature is 440-460 ℃, and the roasting time is 2-4 hours. Wherein the drying temperature is 140 ℃ to 160 ℃ and includes any point value within the temperature range, for example, the drying temperature is 140 ℃, 145 ℃, 150 ℃, 155 ℃ or 160 ℃. The firing temperature is 440 ℃ to 460 ℃ including any point value within the temperature range, for example, the firing temperature is 440 ℃, 445 ℃, 450 ℃, 455 ℃, or 460 ℃. The firing time of 2 h to 4 h includes any point in the time range, for example, firing times of 2 h, 2.5, 3h, 3.5, or 4 h.
Further, in the step of preparing the first precursor, the ratio of the amount of the substance of the manganese element in the soluble manganese salt to the amount of the substance of the M element in the M salt in the first mixed metal salt solution is x 1 :(1－x 1 ) In the step of forming the first coating material, the ratio of the amount of the metal manganese element in the first precursor to the amount of the substance of the lithium element in the first lithium source is x 1 :(x 1 +1)，0.3≤x 1 <1。
In addition, in the step of preparing the second precursor, the ratio of the amount of the substance of the manganese element in the soluble manganese salt to the amount of the substance of the M element in the M salt in the second mixed metal salt solution is x 2 :(1－x 2 ) In the step of forming the positive electrode material, the ratio of the amount of the metal manganese element in the second precursor to the amount of the substance of the lithium element in the second lithium source is x 2 :(x 2 +1)，0<x 2 <0.5。
Thus, by controlling 0.3.ltoreq.x 1 <1 and 0<x 2 <0.5, the content of manganese element in the lithium-rich manganese-based material of the positive electrode material is increased from the outer layer to the inner layer, the second lithium-rich manganese-based coating layer of the outer layer is a low-manganese-content layer, and the first lithium-rich manganese-based coating layer of the inner layer is a high-manganese-content layer.
Further, in terms of material selection, the soluble manganese salt in the first mixed metal salt solution includes at least one of manganese sulfate or manganese nitrate, the first precipitant solution includes at least one of a sodium hydroxide solution or a potassium hydroxide solution, and the first complexing agent solution is an aqueous ammonia solution. The soluble manganese salt in the second mixed metal salt solution comprises at least one of manganese sulfate or manganese nitrate, the second precipitant solution comprises at least one of sodium hydroxide solution or potassium hydroxide solution, and the second complexing agent solution is an ammonia water solution. The carbon source is sucrose. The first lithium source and/or the second lithium source is/are selected from one or more of lithium carbonate, lithium hydroxide.
Further, in terms of reaction conditions, in the step of preparing the first precursor, the conditions under which the precipitation and chemical combination reaction is performed include: and reacting the first reaction system for 3-5 hours under the conditions of pH of 10-13 and reaction temperature of 60-80 ℃. In the step of forming the first coating material, the calcination temperature is 300-600 ℃ and the calcination time is 5-10 h. In the step of preparing the second precursor, the conditions for performing the precipitation-chemical reaction include: and (3) reacting the second reaction system for 3-5 hours under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃. In the step of forming the positive electrode material, the calcination temperature is 300-600 ℃ and the calcination time is 5-10 h.
In a third aspect, an embodiment of the present application further provides a positive electrode sheet, where the positive electrode sheet includes the positive electrode material according to the first aspect, or includes the positive electrode material prepared by the preparation method according to the second aspect.
In a fourth aspect, an embodiment of the present application provides a lithium battery, including the positive electrode material according to the first aspect, as an active material of a positive electrode sheet; or the lithium battery comprises the positive electrode material prepared by the preparation method according to the second aspect, wherein the positive electrode material is used as an active material of a positive electrode plate; or the lithium battery includes the positive electrode sheet as described in the third aspect above. The lithium battery can further comprise a negative electrode plate, a diaphragm and electrolyte, wherein the diaphragm is arranged between the positive electrode plate and the negative electrode plate, the positive electrode plate, the negative electrode plate and the diaphragm are assembled to form a battery cell, and the electrolyte is used for injecting the electrolyte into the battery cell and infiltrating the positive electrode plate and the negative electrode plate.
The technical scheme of the embodiment of the application is further described below with reference to more specific embodiments.
Example 1
The embodiment provides a positive electrode material for use as an active material of a positive electrode sheet in a lithium battery, the positive electrode material including: the inner core is sequentially coated with a first lithium-rich manganese-based coating layer and a second lithium-rich manganese-based coating layer on the periphery of the inner core. Wherein the inner core is a microsphere with a cavity; the chemical formula of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer is as follows: x is x 1 Li 2 MnO 3 • (1－x 1 )LiNiO 2 ，x 1 =0.5; the chemical formula of the lithium-rich manganese-based material in the second lithium-rich manganese-based coating layer is as follows: x is x 2 Li 2 MnO 3 • (1－x 2 )LiNiO 2 ，x 2 =0.1。
The preparation method of the positive electrode material comprises the following steps:
preparing a core: drying at 150 ℃ by taking sucrose as a carbon source through a spray drying method to prepare a carbon microsphere precursor, roasting the carbon microsphere precursor at 450 ℃ for 2-4 hours, and heating and shrinking the sucrose to form a core, wherein the core is a microsphere with a cavity;
preparing a first precursor: placing the inner core, a first mixed metal salt solution with manganese sulfate and nickel sulfate, a sodium hydroxide solution and an ammonia water solution into a reaction kettle to form a first reaction system, continuously stirring, and carrying out precipitation and chemical combination reaction for 3-5 h under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃ to obtain a first precursor; wherein the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 1 :(1－x 1 )，x 1 =0.5；
Forming a first cladding material: mixing a first precursor and a first lithium source lithium carbonate, calcining at 300-600 ℃ for 5-10 hours to coat the periphery of the inner core with a first lithium-rich manganese-based coating layer, and grinding and crushing to obtain a first coating material; wherein the ratio x of the amount of manganese element in the first precursor to the amount of lithium element in the first lithium source 1 :(x 1 +1) ，x 1 =0.5；
Preparation of the firstTwo precursors: placing the first coating material, a second mixed metal salt solution with manganese sulfate and nickel sulfate, a sodium hydroxide solution and an ammonia solution into a reaction kettle to form a second reaction system, continuously stirring, and carrying out precipitation and chemical combination reaction for 3-5 h under the conditions of pH of 10-13 and reaction temperature of 60-80 ℃ to obtain a second precursor; wherein the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 2 :(1－x 2 )，x 2 =0.1；
Forming a positive electrode material: mixing a second precursor and a second lithium source lithium carbonate, and calcining for 5-10 hours at 300-600 ℃ to enable the periphery of the first lithium-rich manganese-based coating layer to be coated with a second lithium-rich manganese-based coating layer, so as to form a positive electrode material; wherein the ratio x of the amount of manganese element in the second precursor to the amount of lithium element in the second lithium source 2 :(x 2 +1) ，x 2 =0.1。
The positive electrode material of this example was subjected to performance characterization, and the particle size distribution of the positive electrode material of this example was measured by a particle size distribution laser diffraction method GB/T19077-2016 using a laser diffraction particle size distribution measuring instrument (Malvern Mastersizer 3000) to obtain D V 50, the results are shown in FIG. 1, and FIG. 1 shows the particle size distribution diagram of the positive electrode material of the present example. The particle surface and the particle cross section of the positive electrode material of this example were tested using a scanning electron microscope, and as a result, as shown in fig. 2 and 3, fig. 2 is a scanning electron microscope image of the particle surface of the positive electrode material of this example, and fig. 3 is a scanning electron microscope image of the particle cross section of the positive electrode material of this example. The positive electrode material of this example was tested (λ=0.154, nm) using a copper target with an X-ray diffractometer (D500 Siemens), at a scanning speed of 3 °/min and a scanning angle of 10 ° -90 °, the radiation source was a cukα radiation source, the test results are shown in fig. 4, and fig. 4 is an XRD test chart of the positive electrode material of this example.
As can be seen from FIG. 1, the positive electrode material D of this embodiment v 50 is 10 μm to 11 μm. As can be confirmed by combining fig. 2 and 3, the positive electrode material of the embodiment has a three-layer structure from inside to outside, and is respectively a microsphere with a cavity as an inner core, a first lithium-rich manganese-based coating layer coating the inner core, a second lithium-rich manganese-based coating layer coating the outermost layer, and a second lithium-rich manganese-based coating layerThe lithium manganese-based coating layer has a thickness greater than 2 microns. As can be seen from FIG. 4, the positive electrode material of the present embodiment is a lithium-rich manganese-based crystal phase, and has a main crystal plane I 003 And I 104 The peak intensity ratio of (2) is about 1.523, which is more favorable for the migration of lithium ions and improves the dynamic performance of the positive electrode material.
Example 2
This embodiment differs from embodiment 1 only in that x 2 =0.2。
Example 3
This embodiment differs from embodiment 1 only in that x 2 =0.3。
Example 4
This embodiment differs from embodiment 1 only in that x 2 =0.4。
Example 5
This embodiment differs from embodiment 1 only in that x 1 =0.3。
Example 6
This embodiment differs from embodiment 1 only in that x 1 =0.4。
Example 7
This embodiment differs from embodiment 1 only in that x 1 =0.6。
Example 8
This embodiment differs from embodiment 1 only in that x 1 =0.7。
Example 9
This embodiment differs from embodiment 1 only in that x 1 =0.8. Correspondingly, in the preparation method of the positive electrode material, in the step of preparing the first precursor, the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 1 :(1－x 1 )，x 1 =0.8; in the step of forming the first cladding material, the ratio x of the amount of manganese element in the first precursor to the amount of lithium element in the first lithium source 1 :(x 1 +1) ，x 1 =0.8。
Example 10
The difference between this embodiment and embodiment 1 is only that the first mixed metal salt solution and the second mixed metal salt solution in this embodiment are both mixed metal salt solutions of manganese nitrate and nickel nitrate, the precipitant solution is potassium hydroxide solution, and the first lithium source and the second lithium source are both lithium hydroxide.
Example 11
The difference between this example and example 1 is only D of the positive electrode material of this example v 50 is 9 μm.
Example 12
The difference between this example and example 1 is only D of the positive electrode material of this example v 50 is 14 μm.
Comparative example 1
This comparative example provides a positive electrode material for use as an active material for a positive electrode sheet in a lithium battery, the positive electrode material comprising: the lithium-rich manganese-based core and the lithium-rich manganese-based coating layer coated on the periphery of the lithium-rich manganese-based core. Wherein, the chemical formula of the lithium-rich manganese-based material in the lithium-rich manganese-based core is as follows: x is x 1 Li 2 MnO 3 • (1－x 1 )LiNiO 2 ，x 1 =0.5; the chemical formula of the lithium-rich manganese-based material in the lithium-rich manganese-based coating layer is as follows: x is x 2 Li 2 MnO 3 • (1－x 2 )LiNiO 2 ，x 2 =0.1。
The preparation method of the positive electrode material comprises the following steps:
preparing a first precursor: placing a first mixed metal salt solution, a sodium hydroxide solution and an ammonia water solution which are provided with manganese sulfate and nickel sulfate into a reaction kettle to form a first reaction system, continuously stirring, and carrying out precipitation and chemical combination reaction for 3-5 h under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃ to obtain a first precursor; wherein the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 1 :(1－x 1 )，x 1 =0.5；
Forming a lithium-rich manganese-based core: mixing the first precursor and the first lithium source lithium carbonate, calcining for 5-10 hours at 300-600 ℃, and grinding and crushing to obtain a lithium-rich manganese-based core; wherein the ratio x of the amount of manganese element in the first precursor to the amount of lithium element in the first lithium source 1 :(x 1 +1) ，x 1 =0.5；
Preparing a second precursor: placing the lithium-rich manganese-based core, a second mixed metal salt solution with manganese sulfate and nickel sulfate, a sodium hydroxide solution and an ammonia solution into a reaction kettle to form a second reaction system, continuously stirring, and carrying out precipitation and chemical combination reaction for 3-5 h under the conditions of pH of 10-13 and reaction temperature of 60-80 ℃ to obtain a second precursor; wherein the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 2 :(1－x 2 )，x 2 =0.1；
Forming a positive electrode material: mixing a second precursor and a second lithium source lithium carbonate, and calcining for 5-10 hours at 300-600 ℃ to enable the periphery of the lithium-rich manganese-based core to be coated with a lithium-rich manganese-based coating layer, so as to form a positive electrode material; wherein the ratio x of the amount of manganese element in the second precursor to the amount of lithium element in the second lithium source 2 :(x 2 +1) ，x 2 =0.1。
Comparative example 2
This comparative example provides a positive electrode material for use as an active material for a positive electrode sheet in a lithium battery, the positive electrode material comprising: the lithium-rich manganese-based coating layer comprises an inner core and a lithium-rich manganese-based coating layer coated on the periphery of the inner core. Wherein the inner core is a microsphere with a cavity; the chemical formula of the lithium-rich manganese-based material in the lithium-rich manganese-based coating layer is as follows: x is x 1 Li 2 MnO 3 • (1－x 1 )LiNiO 2 ，x 1 =0.5。
The preparation method of the positive electrode material comprises the following steps:
preparing a core: drying at 150 ℃ by taking sucrose as a carbon source through a spray drying method to prepare a carbon microsphere precursor, roasting the carbon microsphere precursor at 450 ℃ for 2-4 hours, and heating and shrinking the sucrose to form a core, wherein the core is a microsphere with a cavity;
Preparing a precursor: placing the inner core, the mixed metal salt solution with manganese sulfate and nickel sulfate, the sodium hydroxide solution and the ammonia water solution into a reaction kettle to form a reaction system, continuously stirring, and carrying out precipitation and chemical combination reaction for 3-5 h under the conditions of pH of 10-13 and reaction temperature of 60-80 ℃ to obtain a precursor; wherein the ratio of the mass of manganese element in manganese sulfate to the mass of nickel element in nickel sulfate is x 1 :(1－x 1 )，x 1 =0.5；
Forming a positive electrode material: mixing the precursor and lithium source lithium carbonate, calcining for 5-10 hours at 300-600 ℃ to enable the periphery of the inner core to be coated with a lithium-rich manganese-based coating layer, and grinding and crushing to obtain a positive electrode material; wherein the ratio x of the amount of manganese element in the precursor to the amount of lithium element in the lithium source 1 :(x 1 +1) ，x 1 =0.5。
The performance test of the positive electrode material will be described below
Preparing a positive electrode plate: the weight ratio is 95 percent: 2%:3% respectively weighing corresponding amounts of the positive electrode materials of the examples 1 to N and the comparative examples 1 and 2, conductive carbon black and polyvinylidene fluoride in a stirring tank, and adding a proper amount of N-methyl pyrrolidone (NMP) and stirring for 5 hours to obtain uniform slurry with proper viscosity; and uniformly coating the slurry on the aluminum foil in an extrusion coating mode to form a coating layer, and fully drying in an oven to obtain the positive electrode plate.
Preparing a negative electrode plate: the weight ratio is 95 percent: 2.5%:2.5 percent of artificial graphite, conductive carbon black and sodium carboxymethylcellulose with corresponding amounts are weighed in a stirring tank, and a proper amount of deionized water is added to stir for 6 hours to obtain uniform slurry with proper viscosity; and coating the slurry on copper foil with the thickness of 10 mu m, putting the copper foil into a vacuum oven, and drying the copper foil at 150 ℃ for 10 hours to obtain the negative electrode plate.
Preparing a lithium battery: putting the positive pole piece and the negative pole piece into a press machine for pressing, and then adopting a puncher to intercept a positive pole wafer with phi 15mm and a negative pole wafer with phi 18mm respectively; the positive electrode wafer and the negative electrode wafer are placed in a glove box filled with argon protective atmosphere for battery assembly, wherein 1mol/L lithium hexafluorophosphate is used for dissolving in the following molar ratio of 1:1 and diethyl carbonate as electrolyte; and assembling the anode wafer, the cathode wafer and the polyethylene diaphragm together to form a battery core, then injecting electrolyte, and finally preparing the lithium ion battery.
Battery performance test
(1) Rate discharge capacity
The lithium batteries prepared in examples and comparative examples were charged to 4.5V at 0.5C rate at 25 ℃, and then discharged to 3V at 0.5C rate, and the 0.5C discharge capacity was recorded at this time; then charging to 4.5V at 1C multiplying power, discharging to 3V at 1C multiplying power, and recording the discharge capacity as 1C at the moment;
(2) Cycle performance test
The lithium batteries prepared in examples and comparative examples were charged to 4.5V at 1C rate and then discharged to 3V at 1C rate at 25C, and the capacity of the 1 st turn was taken as an initial capacity, and the capacity of the 200 th turn was divided by the initial capacity to obtain a retention rate value.
The results of the rate discharge capacity and cycle performance test are shown in the following table.
Table 1 results of electrochemical performance test of cells
The experimental results are described in detail below.
1. According to the embodiments 1 to 12, the positive electrode material prepared by the embodiment of the application has good capacity performance and cycle performance, and shows that the microsphere with the cavity is used as the inner core and cooperates with two external lithium-rich manganese-based coating layers, so that the high capacity advantage of the lithium-rich manganese-based material can be truly exerted, and meanwhile, the structural stability problem of the material is improved, so that the material still maintains a higher capacity level after 200 cycles of cycle test.
2. As can be seen from comparative example 1 and comparative example 1, the positive electrode material prepared in the present application can improve the capacity performance of the positive electrode material due to the synergistic effect of the microspheres having cavities and the first lithium-rich manganese-based coating layer. The core-shell structure cathode material of comparative example 1 has the structural characteristics of a microsphere structure with a cavity and two lithium-rich manganese-based coating layers with different manganese contents, although the content of manganese elements decreases from outside to inside, but adopts a solid lithium-rich manganese-based core, so that the material at the center of the lithium-rich manganese-based core cannot fully exert the capacity performance, and the capacity performance and the cycle performance of the cathode material of comparative example 1 are poorer.
3. As can be seen from comparative example 1 and comparative example 2, the cathode material prepared in the embodiment of the present application can improve the structural stability of the cathode material due to the synergistic effect of the second lithium-rich manganese-based coating layer and the first lithium-rich manganese-based coating layer with different manganese element contents, thereby significantly improving the cycle performance of the cathode material. Although the positive electrode material of comparative example 2 also has better capacity performance, the lithium-rich manganese-based coating layer is more easily corroded by the electrolyte, so that the dissolution rate of manganese element becomes faster, the structure of the positive electrode material is gradually unstable in the cyclic charge and discharge process, and the cyclic performance is poor.
4. As is clear from comparing examples 1 to 4, as the manganese content in the second lithium-rich manganese-based coating layer of the outermost layer gradually increases, the cycle performance tends to decrease although the capacity performance of the cathode material increases, because excessive manganese content tends to decrease the structural stability of the material. Wherein, when x 2 When the capacity retention rate is excessively reduced by 0.4, the influence on the cycle performance is excessively large, so that the preferable proportion of the lithium-rich manganese-based material in the second lithium-rich manganese-based coating layer is comprehensively considered as x 2 =0.3 or x 2 <0.3。
5. As can be seen from comparison of examples 1 and examples 5 to 9, as the manganese content in the first lithium-rich manganese-based coating layer of the intermediate layer gradually increases, the capacity performance of the positive electrode material increases, but the cycle performance tends to decrease, and it is seen that the increase of the manganese content has a certain effect on the structural stability of the material. Wherein, when x 1 When =0.7, the capacity retention rate is excessively lowered, and the influence on the cycle performance is excessive, so that the optimal ratio of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer is comprehensively considered as x1=0.6.
6. As can be seen from a comparison of example 1, example 11 and example 12, the positive electrode material structure of the examples of the present application has D v When 50 is 10-11 mu m, the capacity performance and the cycle performance of the positive electrode material can be better combined. Although when D v 50 continue to decrease, the overall capacity performance and cycle performance are also at a better level, but the cycle performance is reduced from that of example 1, and it is seen that although the particles of the cathode material are small in particle sizeThe migration of lithium ions is facilitated to exert higher capacity performance, but the cathode material particles with small particle diameters also affect further improvement of cycle performance due to poor structural stability as in example 1. Although when D v 50, the overall capacity performance and cycle performance can also be at a better level, but the capacity performance is reduced compared to that of example 1, and it is seen that although the large-sized positive electrode material particles have better cycle performance due to stronger structural stability, the capacity performance is further improved due to the extension of the migration path of lithium ions. Based on the above analysis, when D v When 50 is 10-11 mu m, the positive electrode material of the embodiment of the application has more excellent capacity performance and cycle performance.
The positive electrode material and the preparation method thereof, the positive electrode sheet and the lithium battery disclosed in the embodiments of the present application are described in detail, and specific examples are applied to illustrate the principles and the embodiments of the present application, and the description of the above examples is only used for helping to understand the positive electrode sheet and the preparation method thereof, the lithium ion battery and the preparation method thereof and the core ideas thereof: meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the idea of the present application, the present disclosure should not be construed as limiting the present application in summary.
Claims (8)
1. A positive electrode material, characterized in that the positive electrode material comprises:
the inner core is a carbon microsphere with a cavity and a plurality of holes;
the first lithium-rich manganese-based coating layer is coated on the periphery of the inner core, and the chemical formula of the lithium-rich manganese-based material in the first lithium-rich manganese-based coating layer is as follows: x is x 1 Li 2 MnO 3 • (1－x 1 )LiM 1 O 2 Wherein, x is more than or equal to 0.5 1 <1，M 1 Is Ni or Co;
a second lithium-rich manganese-based coating layer, wherein the second lithium-rich manganese-based coating layer is coated on the periphery of the first lithium-rich manganese-based coating layer, and the second lithium-rich coating layer is coated on the periphery of the first lithium-rich manganese-based coating layer The chemical formula of the lithium-rich manganese-based material in the manganese-based coating layer is as follows: x is x 2 Li 2 MnO 3 • (1－x 2 )LiM 2 O 2 Wherein 0 is<x 2 <0.5，M 2 Is Ni or Co;
the mass percentage of the metal manganese element in the first lithium-rich manganese-based coating layer is 26% -46.9%, and the mass percentage of the metal manganese element in the second lithium-rich manganese-based coating layer is more than 0% and less than 26%.
2. The positive electrode material according to claim 1, wherein the positive electrode material has a particle diameter Dv50 of 8 μm to 12 μm; and/or, I of the positive electrode material 003 /I 104 Greater than or equal to 1.3, wherein the I 003 The peak intensity of the diffraction peak of the 003 crystal face of the positive electrode material is the I 104 The peak intensity of the diffraction peak of the 104 crystal face of the positive electrode material.
3. The positive electrode material according to any one of claims 1 to 2, wherein the thickness of the second lithium-rich manganese-based coating layer is greater than or equal to 2 micrometers.
4. A method for producing a positive electrode material, characterized in that the positive electrode material is the positive electrode material according to any one of claims 1 to 3, comprising the steps of:
preparing the core: treating a carbon source by adopting a spray drying method to prepare a carbon microsphere precursor, and roasting the carbon microsphere precursor to form the inner core, wherein the inner core is a microsphere with a cavity;
Preparing a first precursor: mixing the inner core, a first mixed metal salt solution with soluble manganese salt and M salt, a first precipitant solution and a first complexing agent solution to form a first reaction system, and carrying out precipitation and combination reaction on the first reaction system to obtain the first precursor; wherein the M salt in the first mixed metal salt solution is nickel salt and/or cobalt salt;
forming a first cladding material: mixing and calcining the first precursor and a first lithium source to coat the outer periphery of the inner core with the first lithium-rich manganese-based coating layer to form the first coating material;
preparing a second precursor: mixing the first coating material, a second mixed metal salt solution with soluble manganese salt and M salt, a second precipitant solution and a second complexing agent solution to form a second reaction system, and carrying out precipitation and combination reaction on the second reaction system to obtain a second precursor; wherein the M salt in the second mixed metal salt solution is nickel salt and/or cobalt salt;
forming the positive electrode material: and mixing and calcining the second precursor and a second lithium source to enable the periphery of the first lithium-rich manganese-based coating layer to be coated with a second lithium-rich manganese-based coating layer, and controlling the content of metal manganese elements in the second lithium-rich manganese-based coating layer to be lower than that in the first lithium-rich manganese-based coating layer to obtain the positive electrode material.
5. The method according to claim 4, wherein in the step of preparing the first precursor, a ratio of an amount of a substance of manganese element in the soluble manganese salt to an amount of a substance of M element in the M salt in the first mixed metal salt solution is x 1 :(1－x 1 ) X is more than or equal to 0.5 1 <1, a step of; and/or the number of the groups of groups,
in the step of forming the first coating material, the ratio of the amount of the metal manganese element in the first precursor to the amount of the substance of the lithium element in the first lithium source is x 1 :(x 1 +1)，0.5≤x 1 <1, a step of; and/or the number of the groups of groups,
in the step of preparing the second precursor, the ratio of the amount of the substance of the manganese element in the soluble manganese salt to the amount of the substance of the M element in the M salt in the second mixed metal salt solution is x 2 :(1－x 2 ) And 0 is<x 2 <0.5; and/or the number of the groups of groups,
in the step of forming the positive electrode material, the ratio of the amount of the metal manganese element in the second precursor to the amount of the substance of the lithium element in the second lithium source is x 2 :(x 2 +1)，0<x 2 <0.5; and/or the number of the groups of groups,
the soluble manganese salt in the first mixed metal salt solution comprises at least one of manganese sulfate or manganese nitrate, the first precipitant solution comprises at least one of sodium hydroxide solution or potassium hydroxide solution, and the first complexing agent solution is an ammonia water solution; and/or the number of the groups of groups,
The soluble manganese salt in the second mixed metal salt solution comprises at least one of manganese sulfate or manganese nitrate, the second precipitant solution comprises at least one of sodium hydroxide solution or potassium hydroxide solution, and the second complexing agent solution is an ammonia water solution; and/or the number of the groups of groups,
the carbon source is sucrose.
6. The method according to claim 4 or 5, wherein in the step of preparing the core, a spray drying method is adopted at a drying temperature of 140 ℃ to 160 ℃, a baking temperature of 440 ℃ to 460 ℃ and a baking time of 2 h to 4 h; and/or the number of the groups of groups,
in the step of preparing the first precursor, the conditions for performing the precipitation and chemical combination reaction include: reacting the first reaction system for 3-5 hours under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃; and/or the number of the groups of groups,
in the step of forming the first cladding material, the calcining temperature is 300-600 ℃ and the calcining time is 5-10 hours; and/or the number of the groups of groups,
in the step of preparing the second precursor, the conditions for performing the precipitation-chemical reaction include: reacting the second reaction system for 3-5 hours under the conditions that the pH is 10-13 and the reaction temperature is 60-80 ℃; and/or the number of the groups of groups,
in the step of forming the positive electrode material, the calcination temperature is 300-600 ℃ and the calcination time is 5-10 h.
7. A positive electrode sheet, characterized in that the positive electrode sheet comprises the positive electrode material according to any one of claims 1 to 3, or the positive electrode sheet comprises the positive electrode material produced by the positive electrode material production method according to any one of claims 4 to 6.
8. A lithium battery comprising the positive electrode material according to any one of claims 1 to 3, or the positive electrode material produced by the method for producing a positive electrode material according to any one of claims 4 to 6, or the positive electrode sheet according to claim 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310847516.9A CN116565184B (en) | 2023-07-12 | 2023-07-12 | Positive electrode material, preparation method thereof, positive electrode plate and lithium battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310847516.9A CN116565184B (en) | 2023-07-12 | 2023-07-12 | Positive electrode material, preparation method thereof, positive electrode plate and lithium battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN116565184A CN116565184A (en) | 2023-08-08 |
| CN116565184B true CN116565184B (en) | 2023-09-22 |
Family
ID=87504003
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310847516.9A Active CN116565184B (en) | 2023-07-12 | 2023-07-12 | Positive electrode material, preparation method thereof, positive electrode plate and lithium battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116565184B (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953110A (en) * | 2015-06-25 | 2015-09-30 | 中南大学 | Rich-lithium-manganese-based cathode material used for lithium ion battery of hollow structure and preparation method thereof |
| CN109167042A (en) * | 2018-09-03 | 2019-01-08 | 桑德集团有限公司 | Lithium-rich manganese-based anode material of complex carbon material cladding and preparation method thereof, lithium battery |
| CN115842117A (en) * | 2022-11-03 | 2023-03-24 | 欣旺达电动汽车电池有限公司 | Positive electrode material, preparation method thereof, secondary battery and electric equipment |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111435735B (en) * | 2019-12-27 | 2022-10-25 | 蜂巢能源科技有限公司 | Lithium-rich manganese-based positive electrode material and preparation method and application thereof |
-
2023
- 2023-07-12 CN CN202310847516.9A patent/CN116565184B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104953110A (en) * | 2015-06-25 | 2015-09-30 | 中南大学 | Rich-lithium-manganese-based cathode material used for lithium ion battery of hollow structure and preparation method thereof |
| CN109167042A (en) * | 2018-09-03 | 2019-01-08 | 桑德集团有限公司 | Lithium-rich manganese-based anode material of complex carbon material cladding and preparation method thereof, lithium battery |
| CN115842117A (en) * | 2022-11-03 | 2023-03-24 | 欣旺达电动汽车电池有限公司 | Positive electrode material, preparation method thereof, secondary battery and electric equipment |
Non-Patent Citations (1)
| Title |
|---|
| Boosting Electrochemical Performance of Lithium-Rich Manganese-Based Cathode Materials through a Dual Modification Strategy with Defect Designing and Interface Engineering;Li, Zhi et al;《ACS APPLIED MATERIALS & INTERFACES》;第13卷(第45期);第53974-53985页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN116565184A (en) | 2023-08-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113955809B (en) | Nickel-cobalt-manganese-lithium aluminate positive electrode material with shell-core structure and preparation method thereof | |
| CN112794370B (en) | Doped positive electrode material precursor, preparation method and application thereof, doped positive electrode material, preparation method and application thereof | |
| CN112670506B (en) | Nickel-cobalt-manganese-tantalum composite quaternary positive electrode material coated by fast ion conductor and preparation method thereof | |
| CN106910887B (en) | Lithium-rich manganese-based positive electrode material, preparation method thereof and lithium ion battery containing positive electrode material | |
| CN110400929B (en) | Phosphate-coated metal-doped ternary positive electrode active material and preparation and application thereof | |
| CN109390553B (en) | Composite positive electrode material, positive plate and all-solid-state lithium battery | |
| CN111211362B (en) | Lithium-supplementing washing liquid and application thereof, high-nickel multi-element positive electrode material and preparation method thereof | |
| CN113060773A (en) | Preparation method and application of full-concentration-gradient high-nickel ternary material | |
| CN115571927A (en) | Composite in-situ coated high-nickel single crystal positive electrode material and preparation method thereof | |
| CN116581280B (en) | Positive electrode material, preparation method thereof, positive electrode plate and lithium battery | |
| CN109244407A (en) | A kind of method that cladding nickel-cobalt lithium manganate cathode material is blended in magnesia, aluminium oxide | |
| CN116805680A (en) | Composite positive electrode material and preparation method and application thereof | |
| CN116947119A (en) | Nickel-iron-manganese positive electrode material precursor, preparation method thereof, positive electrode material and sodium ion battery | |
| CN115520911B (en) | Lithium nickel composite oxide positive electrode material and preparation method thereof | |
| CN117038979A (en) | Lithium ion battery positive electrode material, preparation method thereof and lithium ion battery | |
| CN116565184B (en) | Positive electrode material, preparation method thereof, positive electrode plate and lithium battery | |
| CN114388779B (en) | Composite ternary positive electrode material, preparation method thereof and lithium ion battery | |
| CN115241435A (en) | Layered Na 3 M 2 XO 6 Oxide-coated modified sodium manganate cathode material and preparation method thereof | |
| CN114906882A (en) | Preparation method and application of niobium-based bimetal oxide negative electrode material | |
| CN111653765A (en) | Preparation method of niobium-doped nickel-cobalt lithium aluminate anode material | |
| Deng et al. | Synthesis and electrochemical properties of Co, Mn-coated LiNiO2 lithium-ion battery cathode materials | |
| CN115057488B (en) | Lithium ion battery positive electrode material with special morphology, and preparation method and application thereof | |
| CN212648280U (en) | Positive pole piece of energy storage device | |
| CN116947122B (en) | Surface cobalt-doped ultrahigh nickel monocrystal ternary cathode material, preparation method thereof and lithium ion battery | |
| CN114122347B (en) | Positive electrode material, preparation method thereof and lithium ion battery |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP03 | Change of name, title or address |
Address after: Room 501, R&D Building, No. 2 Sany Yundu, No. 6 Lanqing Second Road, Luhu Community, Guanhu Street, Longhua District, Shenzhen City, Guangdong Province, 518110 Patentee after: Shenzhen Haichen Energy Storage Technology Co.,Ltd. Country or region after: China Patentee after: Xiamen Haichen Energy Storage Technology Co.,Ltd. Address before: Room 501, R&D Building, No. 2 Sany Yundu, No. 6 Lanqing Second Road, Luhu Community, Guanhu Street, Longhua District, Shenzhen City, Guangdong Province, 518110 Patentee before: Shenzhen Haichen Energy Storage Control Technology Co.,Ltd. Country or region before: China Patentee before: Xiamen Haichen Energy Storage Technology Co.,Ltd. |