CN115571927A - Composite in-situ coated high-nickel single crystal positive electrode material and preparation method thereof - Google Patents
Composite in-situ coated high-nickel single crystal positive electrode material and preparation method thereof Download PDFInfo
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- CN115571927A CN115571927A CN202211307662.4A CN202211307662A CN115571927A CN 115571927 A CN115571927 A CN 115571927A CN 202211307662 A CN202211307662 A CN 202211307662A CN 115571927 A CN115571927 A CN 115571927A
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- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 title claims abstract description 226
- 229910052759 nickel Inorganic materials 0.000 title claims abstract description 141
- 239000013078 crystal Substances 0.000 title claims abstract description 84
- 239000002131 composite material Substances 0.000 title claims abstract description 20
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 239000007774 positive electrode material Substances 0.000 title claims description 21
- 238000011065 in-situ storage Methods 0.000 title abstract description 12
- 239000010410 layer Substances 0.000 claims abstract description 50
- 239000000463 material Substances 0.000 claims abstract description 46
- 239000002243 precursor Substances 0.000 claims abstract description 34
- 239000010416 ion conductor Substances 0.000 claims abstract description 33
- 239000002344 surface layer Substances 0.000 claims abstract description 16
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 10
- SEVNKUSLDMZOTL-UHFFFAOYSA-H cobalt(2+);manganese(2+);nickel(2+);hexahydroxide Chemical compound [OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[Mn+2].[Co+2].[Ni+2] SEVNKUSLDMZOTL-UHFFFAOYSA-H 0.000 claims abstract description 4
- 239000011572 manganese Substances 0.000 claims description 50
- 229910052751 metal Inorganic materials 0.000 claims description 46
- 239000002184 metal Substances 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 27
- 238000005245 sintering Methods 0.000 claims description 26
- 239000010406 cathode material Substances 0.000 claims description 24
- 229910017052 cobalt Inorganic materials 0.000 claims description 16
- 239000010941 cobalt Substances 0.000 claims description 16
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 16
- 229910052748 manganese Inorganic materials 0.000 claims description 15
- 229910018119 Li 3 PO 4 Inorganic materials 0.000 claims description 14
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 14
- 239000003795 chemical substances by application Substances 0.000 claims description 13
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 11
- 229910052760 oxygen Inorganic materials 0.000 claims description 11
- 239000001301 oxygen Substances 0.000 claims description 11
- 150000003839 salts Chemical class 0.000 claims description 10
- 239000000243 solution Substances 0.000 claims description 10
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 9
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 9
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 9
- 239000002904 solvent Substances 0.000 claims description 9
- 150000001768 cations Chemical class 0.000 claims description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000000975 co-precipitation Methods 0.000 claims description 7
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 6
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 6
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000000576 coating method Methods 0.000 claims description 6
- 239000011259 mixed solution Substances 0.000 claims description 6
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 4
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 229910002651 NO3 Inorganic materials 0.000 claims description 3
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 claims description 3
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical class [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 claims description 2
- 238000003837 high-temperature calcination Methods 0.000 claims description 2
- 150000002603 lanthanum Chemical class 0.000 claims description 2
- 159000000003 magnesium salts Chemical class 0.000 claims description 2
- 150000002751 molybdenum Chemical class 0.000 claims description 2
- 230000003647 oxidation Effects 0.000 claims description 2
- 238000007254 oxidation reaction Methods 0.000 claims description 2
- 150000003608 titanium Chemical class 0.000 claims description 2
- 150000003754 zirconium Chemical class 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 150000002823 nitrates Chemical class 0.000 claims 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 claims 1
- 239000010405 anode material Substances 0.000 abstract description 10
- 239000011247 coating layer Substances 0.000 abstract description 8
- 239000002244 precipitate Substances 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 40
- 229910013716 LiNi Inorganic materials 0.000 description 28
- 229910013825 LiNi0.33Co0.33Mn0.33O2 Inorganic materials 0.000 description 23
- 230000008569 process Effects 0.000 description 17
- 230000014759 maintenance of location Effects 0.000 description 14
- 239000003792 electrolyte Substances 0.000 description 8
- 238000005303 weighing Methods 0.000 description 8
- 230000004907 flux Effects 0.000 description 7
- 229910000361 cobalt sulfate Inorganic materials 0.000 description 6
- 229940044175 cobalt sulfate Drugs 0.000 description 6
- KTVIXTQDYHMGHF-UHFFFAOYSA-L cobalt(2+) sulfate Chemical compound [Co+2].[O-]S([O-])(=O)=O KTVIXTQDYHMGHF-UHFFFAOYSA-L 0.000 description 6
- 229940099596 manganese sulfate Drugs 0.000 description 6
- 235000007079 manganese sulphate Nutrition 0.000 description 6
- 239000011702 manganese sulphate Substances 0.000 description 6
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 description 6
- 238000007086 side reaction Methods 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 5
- 239000003513 alkali Substances 0.000 description 5
- 239000011258 core-shell material Substances 0.000 description 5
- 229910001416 lithium ion Inorganic materials 0.000 description 5
- LGQLOGILCSXPEA-UHFFFAOYSA-L nickel sulfate Chemical compound [Ni+2].[O-]S([O-])(=O)=O LGQLOGILCSXPEA-UHFFFAOYSA-L 0.000 description 5
- 229940053662 nickel sulfate Drugs 0.000 description 5
- 229910000363 nickel(II) sulfate Inorganic materials 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 3
- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 230000001351 cycling effect Effects 0.000 description 3
- 238000007599 discharging Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052723 transition metal Inorganic materials 0.000 description 3
- 150000003624 transition metals Chemical class 0.000 description 3
- 238000001291 vacuum drying Methods 0.000 description 3
- 229910013553 LiNO Inorganic materials 0.000 description 2
- 229910002991 LiNi0.5Co0.2Mn0.3O2 Inorganic materials 0.000 description 2
- 239000013543 active substance Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 238000005253 cladding Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 2
- 238000007580 dry-mixing Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910000480 nickel oxide Inorganic materials 0.000 description 2
- -1 nickel-nickel cobalt manganese oxide Chemical compound 0.000 description 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical compound [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 239000011163 secondary particle Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000012798 spherical particle Substances 0.000 description 2
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 229910015950 LiNi0.90Co0.05Mn0.05O2 Inorganic materials 0.000 description 1
- 229910012258 LiPO Inorganic materials 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- NIPNSKYNPDTRPC-UHFFFAOYSA-N N-[2-oxo-2-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethyl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(CNC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 NIPNSKYNPDTRPC-UHFFFAOYSA-N 0.000 description 1
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 230000002238 attenuated effect Effects 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- HMBYCJYERIHCQF-UHFFFAOYSA-F cobalt(2+) manganese(2+) nickel(2+) octahydroxide Chemical compound [OH-].[Co+2].[Ni+2].[Mn+2].[Ni+2].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-].[OH-] HMBYCJYERIHCQF-UHFFFAOYSA-F 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- FYDKNKUEBJQCCN-UHFFFAOYSA-N lanthanum(3+);trinitrate Chemical compound [La+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O FYDKNKUEBJQCCN-UHFFFAOYSA-N 0.000 description 1
- 229910001386 lithium phosphate Inorganic materials 0.000 description 1
- AMWRITDGCCNYAT-UHFFFAOYSA-L manganese oxide Inorganic materials [Mn].O[Mn]=O.O[Mn]=O AMWRITDGCCNYAT-UHFFFAOYSA-L 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- BFDHFSHZJLFAMC-UHFFFAOYSA-L nickel(ii) hydroxide Chemical compound [OH-].[OH-].[Ni+2] BFDHFSHZJLFAMC-UHFFFAOYSA-L 0.000 description 1
- 230000005501 phase interface Effects 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 238000003918 potentiometric titration Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 230000007847 structural defect Effects 0.000 description 1
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 description 1
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G53/00—Compounds of nickel
- C01G53/40—Nickelates
- C01G53/42—Nickelates containing alkali metals, e.g. LiNiO2
- C01G53/44—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese
- C01G53/50—Nickelates containing alkali metals, e.g. LiNiO2 containing manganese of the type [MnO2]n-, e.g. Li(NixMn1-x)O2, Li(MyNixMn1-x-y)O2
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/30—Alkali metal phosphates
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
- H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
- H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
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- 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
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Abstract
The invention belongs to the technical field of anode materials, and particularly relates to a composite in-situ coated high-nickel single crystal anode material and a preparation method thereof. The preparation method comprises the following steps: s1, preparing a high-nickel-doped ternary precursor; s2, obtaining a doped high-nickel ternary oxide; s3, obtaining a precursor of the anode material with the surface layer of nickel-cobalt-manganese hydroxide and the inner shell of high-nickel-doped ternary oxide; s4, obtaining a high-nickel single crystal anode material with an outer layer, a low-nickel core and a high-nickel core; and S5, obtaining the high-nickel single crystal material with the final core being single crystal high-nickel and the middle layer being low-nickel and the surface layer being coated with the fast ion conductor. The invention dopes and sinters the precursor into oxide crystal nucleus, then in-situ co-precipitates low-nickel hydroxide on the oxide crystal nucleus, then adds lithium source to sinter, generates high-nickel single crystal of high-nickel core and low-nickel coating layer in one step, and finally coats fast ion conductor.
Description
Technical Field
The invention belongs to the technical field of anode materials, and particularly relates to a composite in-situ coated high-nickel single crystal anode material and a preparation method thereof.
Background
With the rapid development of new energy automobiles in recent years, high energy density, long cycle life, high safety performance, low cost and the like become core problems concerned by enterprises related to batteries and materials. The ternary material has the advantages of high specific capacity, good capacity retention rate, good high-voltage bearing and charging performance and the like, and becomes an object pursued by a plurality of enterprises, wherein the high-nickel ternary material is a focus of attention because the energy density of the material is greatly improved.
The current ternary cathode material of NCM is mainly of a secondary spherical particle structure, however, the above conventional secondary spherical particle structure has some problems as follows: 1. the mechanical strength of the particle structure is poor, and secondary ball crushing is easily caused in the pole piece compacting process; 2. the internal gaps are many, the structural defects are obvious, the unit pole piece is easy to break in the rolling process, the capacity of the battery is attenuated in the later period, the compaction density is greatly limited, the processing difficulty is increased, and the improvement of the energy density is limited; 3. because the internal pores are large and difficult to coat, the active material is in contact with the electrolyte and can be corroded by HF and the like at high temperature to damage the interface structure, so that the transition metals Ni, co and Mn are dissolved in the electrolyte, and the transition metals are in contact with the electrolyte to cause increased side reactions, generate a large amount of gas, increase the gas pressure of a battery core and expand the battery, thereby causing serious potential safety hazards; 4. the surface of the particles has more defects and side reactions are easy to occur.
Because the single crystal high-nickel anode material has no crystal boundary in secondary particles, the generation of intergranular cracks can be well avoided, the side reaction of electrolyte and the anode material in the circulating process is prevented, and the structural stability and the circulating performance of the high-nickel ternary material are greatly improved. Therefore, many material developers turn the research direction of the ternary material to the single crystal material, and the problems of high mechanical strength and surface side reaction activity of secondary particles and the like are solved by making the ternary cathode material into a single crystal shape and simply coating an extremely thin oxide coating layer on the outer surface of the single crystal material or constructing a concentration gradient core-shell structure. However, the common dry-mixed oxide is easy to be coated unevenly by sintering, and the gradient core-shell structure has the phenomenon of core-shell separation in the circulation process due to the large difference of two-phase structures at the interface. After the charge and discharge are carried out for a certain number of times in a circulating way, the loss of active substances is caused by the structural change of materials due to the dissolution of metal elements of Ni and Co, especially Mn, and the capacity is further reduced. Therefore, an effective coating layer is urgently needed to be constructed on the surface of the high-nickel single crystal to solve the problem of stability of the high-nickel ternary structure.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a composite in-situ coated high-nickel single crystal positive electrode material and a preparation method thereof.
The invention provides a preparation method of a composite coated high-nickel monocrystal cathode material, which comprises the following steps of:
s1, dissolving nickel, cobalt, manganese and soluble salt doped with metal in a solvent according to the element molar ratio, adding ammonia water, mixing, and carrying out coprecipitation reaction to prepare a high-nickel-doped ternary precursor;
s2, carrying out primary high-temperature calcination and oxidation treatment on the high-nickel-doped ternary precursor to obtain a high-nickel-doped ternary oxide;
s3, dissolving soluble salts of nickel, cobalt and manganese in a solvent according to the element molar ratio to form a mixed solution, then adding the material obtained in the S2 into the solution, then adding ammonia water, and carrying out coprecipitation reaction by taking an oxide in the S2 as a crystal nucleus to obtain a precursor of the positive electrode material with a nickel-cobalt-manganese hydroxide inner shell as a high-nickel-doped ternary oxide on the surface layer;
s4, uniformly mixing the precursor of the positive electrode material obtained in the S3 with a lithium source and a fluxing agent in proportion, and sintering in an oxygen atmosphere to obtain a high-nickel single crystal positive electrode material with an outer layer, a low-nickel core and high nickel;
and S5, fully stirring and mixing the positive electrode material obtained in the step S4 with the fast ion conductor according to a certain proportion, and then sintering to obtain the high-nickel single crystal material with the final core being single crystal high-nickel and the middle layer being low-nickel and the fast ion conductor being coated on the surface layer.
Preferably, the soluble salt of nickel, cobalt and manganese in S1 is one or more of sulfate, nitrate, sulfate crystal water compound and nitrate crystal water compound of nickel, cobalt and manganese; wherein the total metal cation concentration is 1-3 mol/L, the metal molar ratio of nickel is 0.75-0.95, the metal molar ratio of cobalt is 0.025-0.1, the metal molar ratio of manganese is 0.005-0.2, and the molar ratio of doping metal is 0.001-0.1.
Preferably, the soluble salt of the doping metal in S1 is one or more of soluble magnesium salt, aluminum salt, molybdenum salt, lanthanum salt, titanium salt and zirconium salt.
Preferably, the solvent in S1 is water.
Preferably, the sintering atmosphere in S2 is oxygen, the sintering temperature is 200-500 ℃, and the sintering time is 2-8 h.
Preferably, the solvent in S3 is water.
Preferably, the total concentration of the metal cations of nickel, cobalt and manganese in S3 is 0.2-2 mol/L, the metal molar ratio of nickel is 0.2-0.6, the metal molar ratio of cobalt is 0.2-0.5, and the metal molar ratio of Mn is 0.3-0.5; the total metal content of the soluble salts of nickel, cobalt and manganese is 0.1-10% of the total metal content of the oxide crystal nucleus in S2.
Preferably, the molar ratio of the total metal molar quantity of the positive electrode material precursor to the lithium source Li metal molar quantity in S4 is 1.0 (0.9-1.2), and the fluxing agent is 0.1% -1% of the total mass of the positive electrode material precursor.
Preferably, the lithium source in S4 is one or more of lithium carbonate and lithium hydroxide; the fluxing agent is one or more of lithium nitrate and lithium carbonate.
Preferably, the sintering conditions in S4 include: the first stage is heated to 300-600 ℃ to calcine for 2-6h, and the second stage is heated to 700-1000 ℃ to calcine for 6-16h.
Preferably, the mass ratio of the fast ion conductor coating amount in S5 to the positive electrode material is 0.01-2%; the fast ion conductor is Li 3 BO 3 、B 2 O 3 、Li 2 B 4 O 7 、Li 3 PO 4 、LiH 2 PO 4 One or more of (a).
Preferably, the sintering atmosphere in S5 is oxygen, the sintering temperature is 200-600 ℃, and the sintering time is 2-8 h.
The invention also provides the composite in-situ coated high-nickel single crystal positive electrode material prepared by the preparation method.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the invention, doping cations are added in the coprecipitation generation process of the precursor, compared with the process of mixing the doping cations in the sintering process of the precursor, the doping cations can be more uniformly distributed in the structure of the precursor during the generation of the precursor, transition metal sites in the high-nickel single crystal ternary positive electrode material can be better replaced in the subsequent sintering process, the crystal structure is stabilized in the charging and discharging process, the formation energy of oxygen vacancies is improved, and the generation of microcracks is inhibited, so that the cycle stability and the thermal stability are improved;
2. according to the invention, a high nickel precursor is pre-sintered into an oxide serving as a crystal nucleus, then a low nickel cobalt manganese hydroxide is co-precipitated on the crystal nucleus, the crystal nucleus is used as a core for in-situ growth of the hydroxide, the low nickel hydroxide can be uniformly distributed on the surface layer of the crystal nucleus of the high nickel oxide, finally a lithium source is added for sintering, and simultaneously a high nickel core and a low nickel cladding layer are generated in situ in one step, compared with a core-shell structure material with a ternary structure and two phase interfaces with obvious element difference, the core-shell structure material is not easy to generate stress to damage the structure in the charging and discharging process; in addition, the Mn content of the surface low nickel layer is higher than that of the core body high nickel Mn layer, so that the dissolving-out phenomenon of Mn element in the circulation process can be effectively relieved;
3. the invention adds the fluxing agent when the precursor is sintered, reduces the melting point of the raw material mixture, reduces the sintering temperature and effectively reduces Li + /Ni 2+ Cation mixed discharging;
4. the outermost fast ion conductor coating layer has excellent lithium ion conductivity, so that the corrosion of HF to the material is reduced in the circulation process, the side reaction with electrolyte and the generation of CEI are reduced, and the circulation life and the rate capability of the anode material can be obviously improved;
5. the thickness of the coating layers of the low nickel layer and the fast ion conductor layer can be adjusted by adjusting the proportion of the coating layers to the high nickel anode of the core body, the process is simple, the requirement on equipment is low, the cost is relatively low, and the method is suitable for industrial production.
Drawings
FIG. 1 is a graph showing the cycle performance of the batteries tested at current densities of 3 to 4.3V,0.5C, for example 1, comparative example 2, and comparative example 4, at 25 ℃;
FIG. 2 is an SEM scan of comparative example 5;
FIG. 3 is a SEM scan of example 1.
Detailed Description
The following will clearly and completely describe the technical solutions in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The cathode material provided by this embodiment is a high nickel single crystal material Li with a high nickel single crystal as a core and a low nickel surface layer coated with a fast ion conductor 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 . Wherein LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 Is a high nickel core, liNi 0.33 Co 0.33 Mn 0.33 O 2 Is low in nickelThe middle layer and the surface layer are Li 3 PO 4 A fast ion conductor cladding.
The preparation method of this example includes the following steps:
s1, weighing nickel sulfate, cobalt sulfate, manganese sulfate and aluminum nitrate according to a metal molar ratio of 0.9. Slowly dropwise adding ammonia water into the mixed solution to adjust the pH value of the solution to 11.8, and continuously stirring the mixed solution at 80 ℃ until the solution is completely changed into xerogel. And then, drying the obtained dry gel in a vacuum drying oven at 100 ℃ for 8h to obtain the Al-doped high-nickel ternary precursor.
And S2, sintering the material obtained in the S1 for 6 hours at 300 ℃ in an oxygen atmosphere to obtain the Al-doped high-nickel ternary oxide.
S3, weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a metal molar ratio of 1. And then, drying the obtained dried gel in a vacuum drying oven at 100 ℃ for 8h to obtain a high nickel precursor with a surface coated with a layer of low nickel-nickel cobalt manganese hydroxide inner shell which is high nickel-nickel cobalt manganese oxide.
S4, weighing the precursor and lithium hydroxide according to the molar weight of the total metal of the high nickel precursor obtained in the S3 and the molar weight of the lithium source Li metal of 1.05, then weighing the lithium carbonate fluxing agent according to 0.2% of the mass of the high nickel precursor, fully mixing, sintering at 500 ℃ for 3h in an oxygen atmosphere, and then sintering at 900 ℃ for 10h to obtain the LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 And (3) a positive electrode material.
S5, weighing a certain mass of the positive electrode material obtained in the step S4, then weighing Li3PO4 according to 1% of the mass ratio of the positive electrode material, fully stirring and uniformly mixing, and then 50% in an oxygen atmosphereProcessing at 0 ℃ for 6h to obtain the cathode material of the embodiment, namely the high-nickel monocrystal material Li with a high-nickel monocrystal as a core and a low-nickel surface layer coated with a fast ion conductor 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2。
Example 2
In this example, the ratio of the total metals in the solution to the total metals in the ternary oxide crystal nucleus of 1% in S3 of example 1 was changed to 0.5% and the remaining steps were the same as in example 1, to obtain a high-nickel single crystal material Li in which the inner core is a high-nickel single crystal, the middle layer is a low-nickel surface layer coated with a fast ion conductor 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Example 3
In this example, the ratio of the total metal in the solution in S3 of example 1 to the total metal in the ternary oxide crystal nucleus of 1% was changed to 2% and the rest of the steps were the same as in example 1, to obtain a high-nickel single crystal material Li in which the inner core is a high-nickel single crystal and the middle layer is a low-nickel surface-coated fast ion conductor 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Example 4
In this example, aluminum nitrate in S1 of example 1 was changed to lanthanum nitrate, and the remaining steps were the same as in example 1 to obtain a high nickel single crystal material Li with a high nickel single crystal core, a low nickel surface layer and a fast ion conductor coated thereon 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 La 0.01 O 2 。
Example 5
In this embodiment, nickel sulfate, cobalt sulfate, and manganese sulfate in S3 of example 1 are respectively weighed according to a metal molar ratio of 1Nickel sulfate, cobalt sulfate and manganese sulfate are respectively weighed according to the metal molar ratio of 5 3 PO 4 @LiNi 0.5 Co 0.2 Mn 0.3 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Example 6
This example shows Li in S5 of example 1 3 PO 4 Modified to Li 3 BO 3 The rest of the steps are the same as the example 1, and the high nickel single crystal material Li with the inner core being the high nickel single crystal, the middle layer being the low nickel surface layer coated with the fast ion conductor is obtained 3 BO 3 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Example 7
In this example, nickel sulfate, cobalt sulfate, manganese sulfate, and aluminum nitrate were respectively weighed in S1 of example 1 at a metal molar ratio of 0.9 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.92 Co 0.02 Mn 0.05 Al 0.01 O 2 。
Example 8
In this example, the lithium carbonate flux in S4 of example 1 was changed to LiNO 3 The rest of the steps are the same as the example 1, and the high nickel single crystal material Li with the inner core being the high nickel single crystal, the middle layer being the low nickel surface layer coated with the fast ion conductor is obtained 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Comparative example 1
The comparative example was prepared as follows, without doping, relative to example 1:
s1, weighing nickel sulfate, cobalt sulfate and manganese sulfate according to a metal molar ratio of 0.9. Ammonia water is slowly dripped into the mixed solution to adjust the pH value of the solution to be 11.8, and the mixed solution is placed at 80 ℃ to be continuously stirred until the solution is completely changed into xerogel. And then, drying the obtained xerogel in a vacuum drying oven at 100 ℃ for 8 hours to obtain the high-nickel NCM ternary precursor.
The subsequent steps are the same as the embodiment 1, and finally the high nickel single crystal material Li with the core being the high nickel single crystal, the middle layer being the low nickel surface layer coated with the fast ion conductor is obtained 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.90 Co 0.05 Mn 0.05 O 2 。
Comparative example 2
Compared with the embodiment 1, the comparative example does not contain the middle low nickel layer, and the specific preparation method is as follows:
s1 and S2 are the same as the embodiment 1, and then S4 and S5 are directly carried out to obtain the high-nickel single crystal material Li with the core being the high-nickel single crystal coated fast ion conductor 3 PO 4 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Comparative example 3
Compared with the embodiment 1, the preparation method of the comparative example does not contain the fast-medium ion conductor layer, and specifically comprises the following steps:
steps S1 to S4 were the same as in example 1, and LiNi having a core of a high-nickel single crystal-coated low-nickel layer was directly obtained 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 And (3) a positive electrode material.
Comparative example 4
Compared with the embodiment 1, the preparation method of the comparative example does not contain the process of in-situ growth of the low-nickel hydroxide precursor, and the low-nickel anode material precursor is prepared by directly dry-mixing the low-nickel hydroxide precursor, and comprises the following steps:
s1 and S2 are the same as in example 1;
S3、weighing commercial Ni according to the proportion that the total metal accounts for 1 percent of the total metal content of the ternary oxide crystal nucleus 0.33 Co 0.33 Mn 0.33 （OH） 2 And uniformly mixing the precursor and the ternary oxide by using a high-speed mixer to obtain a high-nickel precursor with a low-nickel-cobalt-manganese hydroxide inner shell coated on the surface and serving as the high-nickel-cobalt-manganese oxide. The rest steps are the same as the embodiment 1, and finally the high nickel single crystal material Li with the high nickel single crystal as the core, the low nickel as the middle layer and the fast ion conductor coated on the surface layer is obtained 3 PO 4 @LiNi 0.33 Co 0.33 Mn 0.33 O 2 @LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 。
Comparative example 5
Compared with the process of example 1, the preparation method of the comparative example does not contain the process of adding the fluxing agent, and specifically comprises the following steps:
the lithium carbonate flux was weighed in the same manner as in example 1 except that 0.2% of the lithium carbonate flux was not added to S4 in comparison with example 1, thereby obtaining a lithium carbonate flux
3 4 High nickel material LiPO @ containing fluxing agent, with high nickel single crystal as core, low nickel coated fast ion conductor as middle layer
0.33 0.33 0.33 2 0.9 0.04 0.05 0.01 2 LiNiCoMnO@LiNiCoMnAlO。
The high-nickel single crystal material with the high-nickel single crystal as the core, the low-nickel single crystal as the middle layer and the fast ion conductor coating layer as the fast ion conductor coating layer prepared in the above examples and comparative examples is used as the positive electrode, and the button cell is assembled for electrochemical performance test. The method comprises the following specific steps:
mixing a positive electrode active substance, carbon black SuperP and polyvinylidene fluoride (Solvey 5130) (the mass fraction is 5%, and a solvent N-methyl pyrrolidone) according to the mass fraction of 5% to form a slurry, and uniformly coating the slurry on the surface of an aluminum foil to obtain a positive electrode piece; then, a lithium sheet is used as a negative electrode sheet, 1mol/L Ethylene Carbonate (EC) and dimethyl carbonate (DMC) solution of lithium hexafluorophosphate (the mass ratio of EC to DMC is 1) is used as an electrolyte, and the lithium ion battery is assembled in a glove box to obtain the lithium ion battery.
Table 1: the compositions of the materials of the examples and comparative examples and the cycling performance of the cells at 25 ℃ were tested at current densities of 3-4.3V,0.5C
| Sample (I) | High nickel core | Low nickel middle layer | Outer layer of fast ion conductor | Three layer ratio A-B-C | Fluxing agent | Cycle retention ratio of 0.5C-100 |
| Example 1 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 98% |
| Example 2 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-0.5%-1% | Li 2 CO 3 | 94% |
| Example 3 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-2%-1% | Li 2 CO 3 | 93% |
| Example 4 | LiNi 0.9 Co 0.04 Mn 0.05 La 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 97% |
| Example 5 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.5 Co 0.2 Mn 0.3 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 96% |
| Example 6 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 BO 3 | 1-1%-1% | Li 2 CO 3 | 97% |
| Example 7 | LiNi 0.92 Co 0.02 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 98% |
| Example 8 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | LiNO 3 | 98% |
| Comparative example 1 | LiNi 0.9 Co 0.05 Mn 0.05 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 92% |
| Comparative example 2 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | - | Li 3 PO 4 | 1-0%-1% | Li 2 CO 3 | 80% |
| Comparative example 3 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | - | 1-1%-0% | Li 2 CO 3 | 90% |
| Comparative example 4 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | Dry mix-LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | Li 2 CO 3 | 85% |
| Comparative example 5 | LiNi 0.9 Co 0.04 Mn 0.05 Al 0.01 O 2 | LiNi 0.33 Co 0.33 Mn 0.33 O 2 | Li 3 PO 4 | 1-1%-1% | - | 92% |
And (3) carrying out cycle performance test on the lithium ion battery by using an electrochemical tester, wherein the test temperature is 25 ℃, and the cycle performance of the battery is tested at the current density of 3-4.3V and 0.5C. Wherein the three layer proportion A-B-C respectively represents the proportion content of the inner core, the middle layer and the outer layer. Taking example 1 as an example, the ratio of A-B-C of the three layers is 1-1% -1% based on the S3 high nickel inner shell being 1%, the low nickel middle layer being 1% and the S5 fast ion conductor being 1%.
As can be seen from Table 1, the cycle retention rates of the high nickel single crystal cathode materials containing the low nickel intermediate layer in the examples 1 to 6 are all greater than 90% at 0.5C-100 cycles, which is much higher than the cycle retention rate of 80% of the high nickel single crystal cathode material not containing the low nickel intermediate layer in the proportion 2, and the existence of the low nickel intermediate layer is proved to be beneficial to the improvement of the cycle stability of the high nickel single crystal cathode material.
In addition, comparative example 4, in which a dry-mixed low nickel precursor was used as a low nickel intermediate layer, had a cycle retention of 85%, which was greater than comparative example 2 without a low nickel intermediate layer, and lower than the retention of a co-precipitated in-situ grown low nickel intermediate layer, as further demonstrated in examples 1 to 6, the low nickel intermediate layer was advantageous for improving stability.
As can be seen from the attached drawing 1, after 100 cycles of the cycle of the embodiment 1, the capacity is changed from 222.7mAh/g to 215.6mAh/g, the retention rate is 98%, after 100 cycles of the comparative example 2, the capacity is changed from 224.6mAh/g to 179.6mAh/g, the retention rate is 80%, after 100 cycles of the comparative example 4, the capacity is changed from 222.6mAh/g to 189.5mAh/g, the retention rate is 85%, it is further confirmed that the low nickel intermediate layer which grows in situ in the high nickel crystal nucleus through the coprecipitation is relatively to the direct physical dry mixing, the low nickel intermediate layer grows on the high nickel oxide crystal nucleus when the low nickel precursor hydroxide is generated through the coprecipitation, the interface of the low nickel layer and the high nickel inner shell is not easy to generate stress during the charge and discharge processes to damage the structure, and the cycle stability of the material is further improved.
Example 1 compares with examples 2 and 3 and shows that the low nickel middle layer has an optimal value, the low nickel middle layer has higher nickel content and low capacity, the whole material capacity exertion is reduced due to too much coating, the cycling stability is not favorable, and the effective middle layer cannot be formed due to too little coating. Example 7 the cycle retention remained 98% by replacing the high nickel inner shell with Ni90 to Ni92, confirming that the method can be applied to higher nickel materials.
Compared with example 8, example 1 shows that other conditions are unchanged compared with example 1, and example 8 can obtain good cycle retention rate only by changing the type of the fluxing agent, so that the method is proved to be applicable to more fluxing agents and has universality.
Comparative example 5, which contains no flux, has a lower cycle retention than examples 1 and 8, which contain flux; in addition, as can also be seen from fig. 2 and 3, the presence of flux facilitates the formation of single crystals.
Examples 1 and 4 were doped with metallic aluminum and lanthanum, respectively, and compared to comparative example 1, the cycle retention rates of examples 1 and 4 were 98% and 97% respectively, both greater than 92% of comparative example 1. This is because comparative example 1 does not contain high nickel core doping to obtain an undoped high nickel material, whereas examples 1 and 4 can stabilize the crystal structure, improve the oxygen vacancy formation energy, suppress the generation of microcracks, and thus improve the cycle stability of the material, due to the presence of the doped metal, during the charge and discharge processes.
Example 1 compared to comparative example 3, comparative example 3 had a cycle retention (90%) lower than example 1 (98%) because example 1 contained a fast ion conductor outer layer, the presence of which avoided direct contact of the nickelic material with the electrolyte, reduced corrosion of the material by HF during cycling, reduced side reactions with the electrolyte and reduced CEI generation, and thus significantly improved cycle life of the positive electrode material.
And (3) testing the electrochemical multiplying power of the sample: the charge and discharge capacities of the batteries were measured at 25 ℃ and the material compositions of examples and comparative examples at 3-4.3V,0.1C/0.5C/1C/2C current density.
Table 2: rate capability of example 1 and comparative example 3
| Sample (I) | 0.1C discharge capacity mAh/g | 0.5C discharge capacity mAh/g | 1C discharge capacity mAh/g | 2C discharge capacity mAh/g |
| Example 1 | 225.2 | 222.7 | 215.6 | 210.3 |
| Comparative example 3 | 224.0 | 217.6 | 206.1 | 190.2 |
The results are shown in table 2, the material 2C in example 1 discharges 210.3mAh/g, while the material in comparative example 3 only discharges 190.2mAh/g, and further, the fast ion conductor layer is proved to improve the stability of the material, and the fast ion conductor layer has excellent lithium ion conductivity, thereby being beneficial to the high-rate charge and discharge of the material and improving the rate performance of the material.
Surface residual alkali test of sample free: the free surface residual alkali content test results were measured by acid-base potentiometric titration (Switzerland model 905 potentiometric titrator).
Table 3: surface residual alkali test free for samples of example 1, comparative example 2, comparative example 3
| Sample(s) | Residual alkali content on surface (wt%) |
| Example 1 | 0.314 |
| Comparative example 2 | 1.759 |
| Comparative example 3 | 2.218 |
Results are shown in table 3, and the free surface residual alkali tests of the samples of example 1, comparative example 2 and comparative example 3 confirm that the existence of the low-nickel intermediate layer and the fast ion conductor outer layer are beneficial to reducing the surface alkalinity of the high-nickel material.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.
Claims (13)
1. A preparation method of a composite coated high-nickel single crystal cathode material is characterized by comprising the following steps:
s1, dissolving nickel, cobalt, manganese and soluble salt doped with metal in a solvent according to the element molar ratio, adding ammonia water, mixing, and carrying out coprecipitation reaction to prepare a high-nickel-doped ternary precursor;
s2, carrying out primary high-temperature calcination and oxidation treatment on the high-nickel-doped ternary precursor to obtain a high-nickel-doped ternary oxide;
s3, dissolving soluble salts of nickel, cobalt and manganese in a solvent according to the element molar ratio to form a mixed solution, then adding the material obtained in the S2 into the solution, then adding ammonia water, and carrying out a coprecipitation reaction by taking an oxide in the S2 as a crystal nucleus to obtain a positive electrode material precursor with a nickel-cobalt-manganese hydroxide inner shell as a high-nickel-doped ternary oxide on the surface layer;
s4, uniformly mixing the precursor of the cathode material obtained in the step S3 with a lithium source and a fluxing agent in proportion, and sintering in an oxygen atmosphere to obtain a high-nickel single crystal cathode material with an outer layer, a low-nickel core and a high nickel;
and S5, fully stirring and mixing the positive electrode material obtained in the step S4 with the fast ion conductor according to a certain proportion, and then sintering to obtain the high-nickel single crystal material with the final core being single crystal high-nickel and the middle layer being low-nickel and the fast ion conductor being coated on the surface layer.
2. The preparation method of the composite coated high-nickel single crystal cathode material according to claim 1, wherein the soluble salts of nickel, cobalt and manganese in S1 are one or more of sulfates, nitrates, sulfate crystal water compounds and nitrate crystal water compounds of nickel, cobalt and manganese; wherein the total metal cation concentration is 1-3 mol/L, the metal molar ratio of nickel is 0.75-0.95, the metal molar ratio of cobalt is 0.025-0.1, the metal molar ratio of manganese is 0.005-0.2, and the molar ratio of doping metal is 0.001-0.1.
3. The method for preparing a composite coated high nickel single crystal cathode material as claimed in claim 2, wherein the soluble salt of the doping metal in S1 is one or more of soluble magnesium salt, aluminum salt, molybdenum salt, lanthanum salt, titanium salt and zirconium salt.
4. The method for preparing the composite coated high-nickel single crystal cathode material according to claim 3, wherein the solvent in S1 is water.
5. The preparation method of the composite coated high-nickel single crystal cathode material according to claim 1, wherein the sintering atmosphere in S2 is oxygen, the sintering temperature is 200-500 ℃, and the sintering time is 2-8 h.
6. The method for preparing the composite coated high-nickel single crystal cathode material according to claim 1, wherein the solvent in S3 is water.
7. The preparation method of the composite coated high-nickel single crystal cathode material according to claim 6, wherein the total concentration of the metal cations of nickel, cobalt and manganese in S3 is 0.2-2 mol/L, the metal molar ratio of nickel is 0.2-0.6, the metal molar ratio of cobalt is 0.2-0.5, and the metal molar ratio of Mn is 0.3-0.5; the total metal content of the soluble salts of nickel, cobalt and manganese is 0.1-10% of the total metal content of the oxide crystal nucleus in S2.
8. The preparation method of the composite coated high-nickel single crystal cathode material according to claim 1, wherein the molar ratio of the total metal molar quantity of the cathode material precursor to the lithium source Li metal molar quantity in S4 is 1.0 (0.9-1.2), and the fluxing agent is 0.1% -1% of the total mass of the cathode material precursor.
9. The method for preparing the composite coated high-nickel single crystal cathode material according to claim 8, wherein the lithium source in S4 is one or more of lithium carbonate and lithium hydroxide; the fluxing agent is one or more of lithium nitrate and lithium carbonate.
10. The method for preparing the composite coated high nickel single crystal cathode material according to claim 9, wherein the sintering conditions in S4 include: the first stage is heated to 300-600 ℃ to calcine for 2-6h, and the second stage is heated to 700-1000 ℃ to calcine for 6-16h.
11. The preparation method of the composite coated high-nickel single crystal cathode material according to claim 1, wherein the mass ratio of the fast ion conductor coating amount in S5 to the mass ratio of the cathode material is 0.01-2%; the fast ion conductor is Li 3 BO 3 、B 2 O 3 、Li 2 B 4 O 7 、Li 3 PO 4 、LiH 2 PO 4 One or more of (a).
12. The method for preparing a composite coated high nickel single crystal positive electrode material according to claim 11, wherein the sintering atmosphere in S5 is oxygen, the sintering temperature is 200-600 ℃, and the sintering time is 2-8 h.
13. A composite coated high nickel single crystal positive electrode material, characterized in that it is produced by the production method according to one of claims 1 to 12.
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Cited By (2)
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| CN117691095A (en) * | 2024-02-01 | 2024-03-12 | 吉林大学 | Lithium-rich all-solid-state battery positive electrode material, preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108878799A (en) * | 2018-04-24 | 2018-11-23 | 广东邦普循环科技有限公司 | A kind of doping type monocrystalline tertiary cathode material and preparation method thereof of mesoporous lithium aluminosilicate cladding |
| CN112952085A (en) * | 2021-03-15 | 2021-06-11 | 沁新集团(天津)新能源技术研究院有限公司 | Gradient high-nickel single crystal ternary material, preparation method thereof and battery using material |
| CN113479944A (en) * | 2021-09-07 | 2021-10-08 | 中南大学 | Preparation method of modified high-nickel ternary cathode material |
| US20210367233A1 (en) * | 2018-08-28 | 2021-11-25 | Byd Company Limited | Ternary positive electrode material and preparation method therefor, and lithium-ion battery |
| CN114975935A (en) * | 2022-06-02 | 2022-08-30 | 长沙理工大学 | Tungsten-modified high-nickel ternary lithium ion battery positive electrode material and preparation method thereof |
-
2022
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Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108878799A (en) * | 2018-04-24 | 2018-11-23 | 广东邦普循环科技有限公司 | A kind of doping type monocrystalline tertiary cathode material and preparation method thereof of mesoporous lithium aluminosilicate cladding |
| US20210367233A1 (en) * | 2018-08-28 | 2021-11-25 | Byd Company Limited | Ternary positive electrode material and preparation method therefor, and lithium-ion battery |
| CN112952085A (en) * | 2021-03-15 | 2021-06-11 | 沁新集团(天津)新能源技术研究院有限公司 | Gradient high-nickel single crystal ternary material, preparation method thereof and battery using material |
| CN113479944A (en) * | 2021-09-07 | 2021-10-08 | 中南大学 | Preparation method of modified high-nickel ternary cathode material |
| CN114975935A (en) * | 2022-06-02 | 2022-08-30 | 长沙理工大学 | Tungsten-modified high-nickel ternary lithium ion battery positive electrode material and preparation method thereof |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116750810A (en) * | 2023-07-11 | 2023-09-15 | 广东省科学院资源利用与稀土开发研究所 | Single-crystal type high-nickel ternary positive electrode material for high-voltage lithium ion battery and preparation method thereof |
| CN117691095A (en) * | 2024-02-01 | 2024-03-12 | 吉林大学 | Lithium-rich all-solid-state battery positive electrode material, preparation method and application thereof |
| CN117691095B (en) * | 2024-02-01 | 2024-04-23 | 吉林大学 | Lithium-rich all-solid-state battery positive electrode material, preparation method and application thereof |
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