CN114368737A - High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof - Google Patents
High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof Download PDFInfo
- Publication number
- CN114368737A CN114368737A CN202210169389.7A CN202210169389A CN114368737A CN 114368737 A CN114368737 A CN 114368737A CN 202210169389 A CN202210169389 A CN 202210169389A CN 114368737 A CN114368737 A CN 114368737A
- Authority
- CN
- China
- Prior art keywords
- iron phosphate
- lithium
- lithium iron
- compaction
- positive electrode
- 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.)
- Pending
Links
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 title claims abstract description 87
- 238000005056 compaction Methods 0.000 title claims abstract description 22
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 22
- 238000002360 preparation method Methods 0.000 title claims abstract description 16
- 239000010405 anode material Substances 0.000 claims abstract description 12
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 8
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 8
- 238000000227 grinding Methods 0.000 claims description 82
- 239000002245 particle Substances 0.000 claims description 43
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 claims description 41
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 38
- 229910052799 carbon Inorganic materials 0.000 claims description 32
- 238000002156 mixing Methods 0.000 claims description 31
- 238000003756 stirring Methods 0.000 claims description 31
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 26
- 239000002002 slurry Substances 0.000 claims description 26
- 239000013078 crystal Substances 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 21
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 18
- 238000010438 heat treatment Methods 0.000 claims description 18
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 claims description 18
- 230000001681 protective effect Effects 0.000 claims description 16
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 14
- 229910052744 lithium Inorganic materials 0.000 claims description 14
- SNKMVYBWZDHJHE-UHFFFAOYSA-M lithium;dihydrogen phosphate Chemical compound [Li+].OP(O)([O-])=O SNKMVYBWZDHJHE-UHFFFAOYSA-M 0.000 claims description 14
- 239000007790 solid phase Substances 0.000 claims description 14
- 229910000398 iron phosphate Inorganic materials 0.000 claims description 13
- 229910052757 nitrogen Inorganic materials 0.000 claims description 13
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 12
- 150000001875 compounds Chemical class 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims description 11
- 239000000654 additive Substances 0.000 claims description 11
- 230000000996 additive effect Effects 0.000 claims description 11
- 239000008103 glucose Substances 0.000 claims description 11
- 238000001694 spray drying Methods 0.000 claims description 11
- 239000008367 deionised water Substances 0.000 claims description 9
- 229910021641 deionized water Inorganic materials 0.000 claims description 9
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 7
- 229920002472 Starch Polymers 0.000 claims description 7
- 229930006000 Sucrose Natural products 0.000 claims description 7
- 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 claims description 7
- 239000007791 liquid phase Substances 0.000 claims description 7
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 7
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 7
- 239000002904 solvent Substances 0.000 claims description 7
- 239000008107 starch Substances 0.000 claims description 7
- 235000019698 starch Nutrition 0.000 claims description 7
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 6
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims description 6
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 6
- 229910052786 argon Inorganic materials 0.000 claims description 6
- 239000001913 cellulose Substances 0.000 claims description 6
- 229920002678 cellulose Polymers 0.000 claims description 6
- 239000010439 graphite Substances 0.000 claims description 6
- 229910002804 graphite Inorganic materials 0.000 claims description 6
- 229910052734 helium Inorganic materials 0.000 claims description 6
- 239000001307 helium Substances 0.000 claims description 6
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 claims description 6
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 6
- 239000005011 phenolic resin Substances 0.000 claims description 6
- 229920001568 phenolic resin Polymers 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 239000005720 sucrose Substances 0.000 claims description 6
- 229910000399 iron(III) phosphate Inorganic materials 0.000 claims description 5
- 238000012216 screening Methods 0.000 claims description 5
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 claims description 4
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 claims description 4
- 238000010298 pulverizing process Methods 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 3
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 3
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 claims description 3
- 150000004683 dihydrates Chemical class 0.000 claims description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 3
- RTOYJIFECJCKIK-UHFFFAOYSA-K iron(3+) phosphate tetrahydrate Chemical compound O.O.O.O.[Fe+3].[O-]P([O-])([O-])=O RTOYJIFECJCKIK-UHFFFAOYSA-K 0.000 claims description 3
- 238000010902 jet-milling Methods 0.000 claims description 3
- 150000002632 lipids Chemical class 0.000 claims description 3
- QDYVPYWKJOJPBF-UHFFFAOYSA-M lithium;hydroxide;dihydrate Chemical compound [Li+].O.O.[OH-] QDYVPYWKJOJPBF-UHFFFAOYSA-M 0.000 claims description 3
- 239000011777 magnesium Substances 0.000 claims description 3
- 229910052749 magnesium Inorganic materials 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 229910052758 niobium Inorganic materials 0.000 claims description 3
- 239000010955 niobium Substances 0.000 claims description 3
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 3
- 239000010936 titanium Substances 0.000 claims description 3
- 229910052719 titanium Inorganic materials 0.000 claims description 3
- 238000005245 sintering Methods 0.000 description 15
- 239000000463 material Substances 0.000 description 14
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 12
- 229910052726 zirconium Inorganic materials 0.000 description 12
- 239000000843 powder Substances 0.000 description 11
- 238000011049 filling Methods 0.000 description 8
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 6
- 238000012360 testing method Methods 0.000 description 6
- 239000010406 cathode material Substances 0.000 description 5
- 229960004793 sucrose Drugs 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000011068 loading method Methods 0.000 description 3
- 239000004408 titanium dioxide Substances 0.000 description 3
- 238000005303 weighing Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 239000005955 Ferric phosphate Substances 0.000 description 2
- 238000005034 decoration Methods 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 229940032958 ferric phosphate Drugs 0.000 description 2
- 230000005389 magnetism Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000004321 preservation Methods 0.000 description 2
- 235000012431 wafers Nutrition 0.000 description 2
- 239000002033 PVDF binder Substances 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- PQVSTLUFSYVLTO-UHFFFAOYSA-N ethyl n-ethoxycarbonylcarbamate Chemical compound CCOC(=O)NC(=O)OCC PQVSTLUFSYVLTO-UHFFFAOYSA-N 0.000 description 1
- 229940062993 ferrous oxalate Drugs 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- OWZIYWAUNZMLRT-UHFFFAOYSA-L iron(2+);oxalate Chemical compound [Fe+2].[O-]C(=O)C([O-])=O OWZIYWAUNZMLRT-UHFFFAOYSA-L 0.000 description 1
- YOBAEOGBNPPUQV-UHFFFAOYSA-N iron;trihydrate Chemical compound O.O.O.[Fe].[Fe] YOBAEOGBNPPUQV-UHFFFAOYSA-N 0.000 description 1
- -1 lithium hexafluorophosphate Chemical compound 0.000 description 1
- GLXDVVHUTZTUQK-UHFFFAOYSA-M lithium hydroxide monohydrate Substances [Li+].O.[OH-] GLXDVVHUTZTUQK-UHFFFAOYSA-M 0.000 description 1
- 229940040692 lithium hydroxide monohydrate Drugs 0.000 description 1
- 239000000395 magnesium oxide Substances 0.000 description 1
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 1
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- YQCIWBXEVYWRCW-UHFFFAOYSA-N methane;sulfane Chemical compound C.S YQCIWBXEVYWRCW-UHFFFAOYSA-N 0.000 description 1
- ZKATWMILCYLAPD-UHFFFAOYSA-N niobium pentoxide Inorganic materials O=[Nb](=O)O[Nb](=O)=O ZKATWMILCYLAPD-UHFFFAOYSA-N 0.000 description 1
- URLJKFSTXLNXLG-UHFFFAOYSA-N niobium(5+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Nb+5].[Nb+5] URLJKFSTXLNXLG-UHFFFAOYSA-N 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000011056 performance test Methods 0.000 description 1
- DPTATFGPDCLUTF-UHFFFAOYSA-N phosphanylidyneiron Chemical compound [Fe]#P DPTATFGPDCLUTF-UHFFFAOYSA-N 0.000 description 1
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000002356 single layer Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Images
Classifications
-
- 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
- C01B25/45—Phosphates containing plural metal, or metal and ammonium
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/05—Preparation or purification of carbon not covered by groups C01B32/15, C01B32/20, C01B32/25, C01B32/30
-
- 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
- H01M4/5825—Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/11—Powder tap density
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
Abstract
The invention provides a preparation method of a high-compaction and high-capacity lithium iron phosphate positive electrode material. The lithium iron phosphate anode material prepared by the invention is mainly applied to an anode for a lithium ion battery, and aims to further improve the energy density and reduce the cost of the lithium iron phosphate battery.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a high-compaction high-capacity lithium iron phosphate positive electrode material, and a preparation method and application thereof.
Background
In the 21 st century, lithium ion secondary batteries have been developed rapidly, benefiting from the technical renewal of positive and negative electrodes, diaphragms and electrolyte main materials. Lithium iron phosphate is well known as a positive electrode material with low cost, high safety, long cycle and high capacity, and plays a great role in the lithium battery industry. However, lithium iron phosphate has a natural disadvantage of very poor conductivity and a very poor theoretical specific capacity, and thus cannot be practically used. Through the diligent efforts of numerous researchers, lithium iron phosphate is gradually commercialized and practical. The lithium iron phosphate used as the anode goes through several development stages, and firstly, the lithium iron phosphate is practical, carbon-coated and nanocrystallized; second, high capacity; adopting ferric phosphate and ferrous oxalate; third, cost reduction is achieved. Although the lithium iron phosphate market is eaten by ternary materials due to promotion of a policy of high-energy-density lithium batteries, the lithium iron phosphate market is favored by the market all the time due to high cost performance and high safety. Therefore, the development of high-capacity and high-compaction lithium iron phosphate becomes an important task at present. At present, high-capacity lithium iron phosphate is prepared by lithium-blending grinding, spray granulation and sintering through iron phosphate guide. However, the iron phosphate is high in cost, and the sintering mode is limited by the iron-phosphorus ratio.
Disclosure of Invention
In view of the above, the technical problem to be solved by the present invention is to provide a high-compaction and high-capacity lithium iron phosphate positive electrode material and a preparation method thereof.
The invention provides a preparation method of a high-compaction and high-capacity lithium iron phosphate positive electrode material, which comprises the following steps of:
A) mixing iron oxide, lithium dihydrogen phosphate and a carbon source in a solid phase to obtain a mixture;
B) under the condition of protective atmosphere, carrying out heat treatment on the mixture to obtain a lithium iron phosphate primary seed crystal;
C) mixing and grinding the lithium iron phosphate primary seed crystal, a lithium source, a carbon source and an additive in a liquid phase to obtain slurry;
D) after the slurry is subjected to spray drying, carrying out secondary heat treatment under the condition of protective atmosphere to obtain a lithium iron phosphate process product;
E) and crushing the lithium iron phosphate process product, and then screening and demagnetizing to obtain the high-compaction and high-capacity lithium iron phosphate anode material.
Preferably, the iron oxide is selected from Fe2O3、FeO、Fe3O4One or more of; the particle size of the iron oxide is less than 1 mu m, and the tap density is more than or equal to 4g/cm3The specific surface area is less than or equal to 50m2/g；
The purity of the lithium dihydrogen phosphate is more than or equal to 99 percent, and the water content is less than 0.02 percent;
the carbon source is selected from one or more of glucose, starch, sucrose, phenolic resin, cellulose, citric acid, graphite and carbon tubes.
Preferably, the iron oxide and the lithium dihydrogen phosphate are fed according to the molar ratio of the Fe element to the P element of 1 (0.95-1.0), and the mass of the carbon source accounts for 4-35% of the mass of the iron oxide.
Preferably, the solid phase mixing equipment used in the solid phase mixing method is selected from a three-dimensional mixer or a high-speed mixer, preferably a high-speed mixer, the solid phase mixing is firstly carried out at a low speed, and then is carried out at a high speed, the mixing parameters of the high-speed mixer are that the low-speed rotating speed is less than 500PPM, the time is 10-30min, the high-speed rotating speed is more than 1000PPM, and the high-speed rotating speed is 1-5 h.
Preferably, the protective atmosphere conditions are selected from one or more of nitrogen, helium and argon;
the temperature of the heat treatment is 650-800 ℃, and the time is 8-20 h.
Preferably, in step C), the lithium source is selected from one or more of lithium carbonate, lithium hydroxide dihydrate and lithium nitrate;
the iron phosphate is selected from ferric orthophosphate, dihydrate and lithium iron phosphate or ferric phosphate tetrahydrate, the particle size of the iron phosphate is less than or equal to 9 mu m, and the tap density is 0.6-1.2 g/cm3Specific surface area of 4 to 15m2/g；
The carbon source is one or more of glucose, phenolic resin, starch, sucrose, lipid substances, cellulose, citric acid, graphite and carbon tubes;
the additive is selected from a compound of titanium, a compound of magnesium, a compound of aluminum or a compound of niobium;
the molar ratio of metal elements in the lithium iron phosphate primary seed crystal, the lithium iron phosphate, the lithium source and the additive is 1: (0.1-9): (1.0-1.14): (0.001-0.02);
the weight of the carbon source is 0.5-40% of the weight of the lithium iron phosphate primary seed crystal;
the solvent used for liquid phase mixing is one or more of deionized water, ethanol, acetone and NMP; the dosage of the solvent is 20-65% of the total weight of the solid in the step C);
the stirring speed during the mixing is 15-60HZ, and the stirring time is 0.5-4 h.
Preferably, the protective atmosphere conditions are selected from one or more of nitrogen, helium and argon;
the temperature of the heat treatment is 610-800 ℃, and the time is 5-18 h.
Preferably, the pulverization is selected from jet milling, the pulverization frequency is 15-45 HZ, the classification frequency is 12-60 HZ, and the air source pressure is 0.4-1.5 Mpa.
The invention also provides a high-compaction and high-capacity lithium iron phosphate positive electrode material prepared by the preparation method, wherein the magnetic substance of the lithium iron phosphate positive electrode material is less than or equal to 500PPB, and the granularity is less than or equal to 4 mu m.
The invention also provides a lithium ion battery which comprises the high-compaction and high-capacity lithium iron phosphate anode material.
Compared with the prior art, the invention provides a preparation method of a high-compaction and high-capacity lithium iron phosphate positive electrode material, which comprises the following steps: A) mixing iron oxide, lithium dihydrogen phosphate and a carbon source in a solid phase to obtain a mixture; B) under the condition of protective atmosphere, carrying out heat treatment on the mixture to obtain a lithium iron phosphate primary seed crystal; C) mixing and grinding the lithium iron phosphate primary seed crystal, a lithium source, a carbon source and an additive in a liquid phase to obtain slurry; D) after the slurry is subjected to spray drying, carrying out secondary heat treatment under the condition of protective atmosphere to obtain a lithium iron phosphate process product; E) and crushing the lithium iron phosphate process product, and then screening and demagnetizing to obtain the high-compaction and high-capacity lithium iron phosphate anode material. The lithium iron phosphate anode material prepared by the invention is mainly applied to an anode for a lithium ion battery, and aims to further improve the energy density and reduce the cost of the lithium iron phosphate battery.
Drawings
Fig. 1 is an SEM image of the lithium iron phosphate positive electrode material prepared in example 1;
fig. 2 is an SEM image of the lithium iron phosphate positive electrode material prepared in example 1;
fig. 3 is an SEM image of the lithium iron phosphate positive electrode material prepared in example 1;
fig. 4 is an SEM image of the lithium iron phosphate positive electrode material prepared in example 2.
Detailed Description
The invention provides a preparation method of a high-compaction and high-capacity lithium iron phosphate positive electrode material, which comprises the following steps of:
A) mixing iron oxide, lithium dihydrogen phosphate and a carbon source in a solid phase to obtain a mixture;
B) under the condition of protective atmosphere, carrying out heat treatment on the mixture to obtain a lithium iron phosphate primary seed crystal;
C) mixing and grinding the lithium iron phosphate primary seed crystal, a lithium source, a carbon source and an additive in a liquid phase to obtain slurry;
D) after the slurry is subjected to spray drying, carrying out secondary heat treatment under the condition of protective atmosphere to obtain a lithium iron phosphate process product;
E) and crushing the lithium iron phosphate process product, and then screening and demagnetizing to obtain the high-compaction and high-capacity lithium iron phosphate anode material.
The invention mixes iron oxide, lithium dihydrogen phosphate and carbon source in solid phase to obtain mixture.
Wherein the iron oxide is selected from Fe2O3、FeO、Fe3O4One or more of; the particle size of the iron oxide is less than 1 mu m, and the tap density is more than or equal to 4g/cm3The specific surface area is less than or equal to 50m2/g；
The purity of the lithium dihydrogen phosphate is more than or equal to 99 percent, and the water content is less than 0.02 percent;
the carbon source is selected from one or more of glucose, starch, sucrose, phenolic resin, cellulose, citric acid, graphite and carbon tubes.
The mass of the iron oxide and the lithium dihydrogen phosphate is fed according to the molar ratio of the Fe element to the P element of 1 (0.95-1.0), preferably any value between 1:0.95, 1:0.96, 1:0.97, 1:0.98, 1:0.99, 1:1 or 1 (0.95-1.0), and the mass of the carbon source accounts for 4-35% of the mass of the iron oxide, preferably any value between 4%, 5%, 10%, 15%, 20%, 25%, 30%, 35% or 4-35%.
The solid phase mixing equipment used in the solid phase mixing method is selected from a three-dimensional mixer or a high-speed mixer, preferably the high-speed mixer, the solid phase mixing is firstly carried out at low speed and then carried out at high speed, the mixing parameters of the high-speed mixer are that the low-speed rotating speed is less than 500PPM, the time is 10-30min, the high-speed rotating speed is more than 1000PPM, and the high-speed rotating speed is 1-5 h.
Then weighing the fully mixed mixture, loading the mixture into a bowl, putting the bowl into a kiln with protective atmosphere, and carrying out heat treatment to obtain the lithium iron phosphate primary seed crystal
Wherein the protective atmosphere conditions are selected from one or more of nitrogen, helium and argon;
the temperature of the heat treatment is 650-800 ℃, preferably 650, 700, 750, 800, or any value between 650-800 ℃, and the time is 8-20 h, preferably any value between 8, 10, 12, 14, 16, 18, 20, or 8-20 h.
And then, mixing and grinding the lithium iron phosphate primary seed crystal, a lithium source, a carbon source and an additive to obtain slurry.
Wherein the lithium source is selected from one or more of lithium carbonate, lithium hydroxide dihydrate and lithium nitrate;
the iron phosphate is selected from ferric orthophosphate, dihydrate and lithium iron phosphate or ferric phosphate tetrahydrate, the particle size of the iron phosphate is less than or equal to 9 mu m, and the tap density is 0.6-1.2 g/cm3Specific surface area of 4 to 15m2/g；
The carbon source is one or more of glucose, phenolic resin, starch, sucrose, lipid substances, cellulose, citric acid, graphite and carbon tubes;
the additive is selected from a compound of titanium, a compound of magnesium, a compound of aluminum or a compound of niobium;
the molar ratio of metal elements in the lithium iron phosphate primary seed crystal, the lithium iron phosphate, the lithium source and the additive is 1: (0.1-9): (1.0-1.14): (0.001 to 0.02), preferably 1: (0.5-6): (1.05-1.10): (0.005 to 0.015), and more preferably 1: (1-5): (1.05-1.10): (0.010-0.015);
the weight of the carbon source is 0.5-40% of the weight of the lithium iron phosphate primary seed crystal, preferably 0.5%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or any value between 0.5-40%;
the solvent used for liquid phase mixing is one or more of deionized water, ethanol, acetone and NMP; the amount of the solvent is 20% to 65% of the total weight of the solids in step C), preferably 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or any value between 20% to 65%;
the stirring speed during mixing is 15-60HZ, preferably any value between 15, 20, 25, 30, 35, 40, 45, 50, 55, 60 or 15-60HZ, and the stirring time is 0.5-4h, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4 or any value between 0.5-4 h.
After being uniformly mixed, the mixture is ground by a sand mill to reach a certain particle size, and slurry is obtained.
Wherein the grinding is performed by rough grinding and then finish grinding. Specifically, the particle size of the zirconium balls for coarse grinding is 1-5 microns, the rotating speed is 300-700 RPM, the stirring speed is 15-55HZ, the coarse grinding time is 1-8 hours, and the particle size of the product after coarse grinding is less than or equal to 2 microns; the grain diameter of the zirconium ball for fine grinding is 0.1-0.8 mu m, the rotating speed is 400-800RPM, the stirring speed is 20-60HZ, the fine grinding time is 2-24h, and the fine grinding grain diameter is less than or equal to 1.0 mu m.
And then, carrying out spray drying on the slurry, wherein the inlet air temperature is 190-300 ℃, preferably 190, 200, 250, 300 or any value between 190-300 ℃, and the outlet air temperature is 90-140 ℃, preferably 90, 100, 110, 120, 130, 140 or any value between 90-140 ℃.
Carrying out secondary heat treatment on the particles obtained after spray drying under the condition of protective atmosphere to obtain a lithium iron phosphate process product
The protective atmosphere condition is selected from one or more of nitrogen, helium and argon;
the temperature of the heat treatment is 610-800 ℃, preferably 610, 650, 700, 750, 800, or any value between 610-800 ℃, and the time is 5-18 h, preferably 5, 10, 12, 15, 18, or any value between 5-18 h.
And finally, crushing the lithium iron phosphate process product, screening and demagnetizing to obtain the high-compaction and high-capacity lithium iron phosphate anode material.
In the invention, the crushing is selected from jet milling, the crushing frequency is 15-45 HZ, the classification frequency is 12-60 HZ, and the air source pressure is 0.4-1.5 Mpa. The method of demagnetizing is not particularly limited, and may be a method known to those skilled in the art.
The invention also provides a high-compaction and high-capacity lithium iron phosphate anode material obtained by the preparation method, the magnetic substance of the lithium iron phosphate anode material is less than or equal to 500PPB, the granularity is less than or equal to 4 mu m,
the invention also provides a lithium ion battery which comprises the high-compaction and high-capacity lithium iron phosphate anode material.
The lithium iron phosphate anode material prepared by the invention is mainly applied to an anode for a lithium ion battery, and aims to further improve the energy density and reduce the cost of the lithium iron phosphate battery.
For further understanding of the present invention, the following description is made with reference to the following examples to illustrate the highly compacted and high-capacity lithium iron phosphate positive electrode material provided by the present invention, and the preparation method and application thereof, and the scope of the present invention is not limited by the following examples.
Example 1
1) 320kg of iron sesquioxide (particle size 0.45 μm, tap density 4.8g/cc, specific surface area 36 m)2g-1) Putting 416kg of lithium dihydrogen phosphate and 20kg of glucose into a high-speed mixer, setting the low speed of the high-speed mixer to be 360RPM for 15min, setting the high-speed rotation speed to be 1500RPM for 2.4h, uniformly mixing, then loading into a sagger, setting the sagger into the sagger to be 3.5kg, carrying out heat treatment in a nitrogen-filled kiln, keeping the sintering temperature at 780 ℃, keeping the temperature for 10h, and discharging to obtain lithium iron phosphate primary seed crystals;
2) adding the lithium iron phosphate primary seed crystal, 906kg of iron phosphate (with the particle size of 7 microns), 462kg of lithium carbonate (5 microns), 3.2kg of titanium dioxide and 190kg of glucose in the step 1 into a feeding tank filled with 2209kg of deionized water, stirring at the speed of 30HZ for 1.0h, transferring to coarse grinding, then carrying out coarse grinding at the stirring speed of 32HZ for coarse grinding, the particle size of a zirconium ball for coarse grinding of 3 microns, the rotation speed of coarse grinding of 450RPM for 5h, the particle size after coarse grinding of 3.4 microns, then carrying out fine grinding at the stirring speed of 38HZ for fine grinding, the particle size of a zirconium ball for fine grinding of 0.4 microns, the rotation speed of fine grinding of 650RPM for fine grinding of 6.2h, the particle size after fine grinding of 0.7 microns and finishing the grinding of the slurry.
3) And (3) carrying out spray drying on the slurry obtained in the step (2), wherein the air inlet temperature is 230 ℃, the air outlet temperature is 95 ℃, and the slurry stirring speed is 26HZ, so as to obtain dry powder.
4) And (3) filling the dry powder obtained in the step (3) into a pot with the pot filling amount of 4.5kg, and putting the pot into a kiln filled with nitrogen, wherein the sintering temperature of the kiln is 710 ℃, and the sintering time is 8 hours.
5) And conveying the sintered material to a jet mill, wherein the crushing frequency is 42HZ, the classification frequency is 38HZ, the air source pressure is 1.0Mpa, and the material passes through a 350-mesh screen and is demagnetized by adopting a 2000GS electromagnet to finally obtain a finished product of the lithium iron phosphate cathode material. The particle diameter of the finished product is 1.8 mu m, and the specific surface area is 10.9m2(g), tap density 1.2g/cm3。
Referring to fig. 1 to 3, fig. 1 to 3 are SEM images of the lithium iron phosphate positive electrode material prepared in example 1.
Example 2
1) The sintering temperature is adjusted to 760 ℃, and the heat preservation time is kept to 14 hours, which is consistent with that of the embodiment 1;
2) adding the lithium iron phosphate primary seed crystal, 805kg of iron phosphate (with the particle size of 4 microns), 410kg of lithium carbonate (with the particle size of 5 microns), 5.3kg of niobium pentoxide and 210kg of glucose into a feeding tank filled with 2280kg of deionized water, stirring at a stirring speed of 32HZ for 1.2h, transferring to coarse grinding, then performing coarse grinding at a stirring speed of 32HZ for coarse grinding, at a particle size of 3 microns of zirconium balls for coarse grinding, at a coarse grinding rotation speed of 450RPM, for a coarse grinding time of 5h, at a particle size of 3.1 microns after coarse grinding, then performing fine grinding at a stirring speed of 38HZ for fine grinding, at a particle size of 0.4 microns of zirconium balls for fine grinding, at a fine grinding rotation speed of 650RPM, for a fine grinding time of 6.2h, at a particle size of 0.66 microns after fine grinding, and finishing the grinding of slurry.
3) And (3) carrying out spray drying on the slurry obtained in the step (2), wherein the air inlet temperature is 230 ℃, the air outlet temperature is 95 ℃, and the slurry stirring speed is 26HZ, so as to obtain dry powder.
4) And (3) filling the dry powder obtained in the step (3) into a pot with the pot filling amount of 4.5kg, and putting the pot into a kiln filled with nitrogen, wherein the sintering temperature of the kiln is 710 ℃, and the sintering time is 8 hours.
5) And conveying the sintered material to a jet mill, wherein the crushing frequency is 42HZ, the classification frequency is 38HZ, the air source pressure is 1.0Mpa, the material passes through a 350-mesh screen, and the magnetism of the material is removed by adopting an 20000GS electromagnet, so that a finished product of the lithium iron phosphate cathode material is finally obtained. The particle diameter of the finished product is 1.5 mu m, and the specific surface area is 11.2m2(g), tap density 1.14g/cm3. Referring to fig. 4, fig. 4 is an SEM image of the lithium iron phosphate positive electrode material prepared in example 2
Example 3
1) The sintering temperature is adjusted to 800 ℃, and the heat preservation time is kept to be consistent with that of 1) in the embodiment 1 after 6 hours;
2) adding 2416kg of iron phosphate primary seed crystal, 2412 kg of iron phosphate (with the particle size of 4 microns), 1232kg of lithium carbonate (with the particle size of 5 microns), 3.8kg of magnesium oxide and 600kg of glucose into a feeding tank filled with 6080kg of deionized water, stirring at the speed of 34HZ for 2.5 hours, transferring to coarse grinding, then carrying out coarse grinding at the stirring speed of 35HZ for coarse grinding, the particle size of zirconium balls for coarse grinding of 3 microns, the rotation speed of the coarse grinding of 490, the RPM for coarse grinding of 8 hours, the particle size of 4.5 microns after coarse grinding, then carrying out fine grinding at the stirring speed of 40HZ for fine grinding, the particle size of zirconium balls for fine grinding of 0.4 microns, the rotation speed of the fine grinding of 690RPM, the time of the fine grinding of 12 hours, the particle size of 0.54 microns after fine grinding, and finishing the grinding of the slurry.
3) And (3) carrying out spray drying on the slurry obtained in the step (2), wherein the air inlet temperature is 230 ℃, the air outlet temperature is 95 ℃, and the slurry stirring speed is 26HZ, so as to obtain dry powder.
4) And (3) filling the dry powder obtained in the step (3) into a pot, wherein the pot filling amount is 4.5kg, putting the pot into a kiln filled with nitrogen, and sintering the pot at the temperature of 760 ℃ for 7 hours.
5) And conveying the sintered material to a jet mill, wherein the crushing frequency is 42HZ, the classification frequency is 38HZ, the air source pressure is 1.0Mpa, the material passes through a 350-mesh screen, and the magnetism of the material is removed by adopting an 20000GS electromagnet, so that a finished product of the lithium iron phosphate cathode material is finally obtained. The particle diameter of the finished product is 1.46 mu m, and the specific surface area is 11.9m2(g), tap density 1.02g/cm3。
Example 4
310kg of ferroferric oxide (particle size of 0.47 mu m, tap density of 5.1g/cc, specific surface area of 40 m)2g-1) Putting 408kg of lithium dihydrogen phosphate and 12kg of starch into a high-speed mixer, setting the low speed of the high-speed mixer to be 310RPM for 20min, setting the high-speed rotation speed to be 1700RPM for 1.5h, uniformly mixing, then loading into a sagger, setting the sagger into the sagger to be 3.0kg, carrying out heat treatment in a nitrogen-filled kiln, carrying out sintering at 740 ℃, keeping the temperature for 12h, and discharging to obtain lithium iron phosphate primary seed crystals;
2) adding the primary seed crystal of the lithium iron phosphate, 906kg of iron phosphate (with the grain diameter of 4.7 microns), 432kg of lithium hydroxide monohydrate (4.2 microns), 2.4kg of titanium dioxide and 96kg of cane sugar in the step 1 into a feeding tank filled with 1500kg of deionized water, stirring at a stirring speed of 30HZ for 1.3h, transferring to a coarse grinding process, then carrying out coarse grinding at a stirring speed of 34HZ for coarse grinding, a zirconium ball for coarse grinding at a grain diameter of 3 microns, at a coarse grinding rotating speed of 450RPM for coarse grinding for 6h, and after coarse grinding, carrying out the grain diameter of 2.7 microns, then carrying out fine grinding at a stirring speed of 38HZ for fine grinding, a zirconium ball for fine grinding at a grain diameter of 0.4 microns, at a fine grinding rotating speed of 610RPM for fine grinding for 6.8h, and after fine grinding, the grain diameter of 0.57 microns, and finishing the grinding of the slurry.
3) And (3) carrying out spray drying on the slurry finished in the step (2), wherein the air inlet temperature is 225 ℃, the air outlet temperature is 100 ℃, and the slurry stirring speed is 26HZ, so as to obtain dry powder.
4) And (3) filling the dry powder obtained in the step (3) into a pot with the pot filling amount of 4.5kg, and putting the pot into a kiln filled with nitrogen, wherein the sintering temperature of the kiln is 710 ℃, and the sintering time is 8 hours.
5) And conveying the sintered material to a jet mill, wherein the crushing frequency is 39HZ, the classification frequency is 41HZ, the air source pressure is 1.0Mpa, and the material passes through a 350-mesh screen and is demagnetized by adopting a 2000GS electromagnet to finally obtain a finished product of the lithium iron phosphate cathode material. The particle diameter of the finished product is 1.37 mu m, and the specific surface area is 9.7m2(g), tap density 1.11g/cm3。
Comparative example 1
1) 320kg of ferric oxide, 906kg of ferric phosphate, 416kg of lithium dihydrogen phosphate, 462kg of lithium carbonate, 210kg of glucose and 3.2kg of titanium dioxide are put into a feeding tank filled with 3200kg of deionized water, dispersed by stirring for 2.5 hours at a stirring speed of 30HZ, and transferred to coarse grinding at a stirring speed of 32HZ, the particle size of a zirconium ball for coarse grinding is 3 mu m, the rotation speed of the coarse grinding is 450RPM, the time of the coarse grinding is 7 hours, the particle size after the coarse grinding is 4.2 mu m, then fine grinding is carried out, the stirring speed of the fine grinding is 38HZ, the particle size of the zirconium ball for fine grinding is 0.4 mu m, the rotation speed of the fine grinding is 650RPM, the time of the fine grinding is 7.8 hours, the particle size after the fine grinding is 0.76 mu m, and the grinding of the slurry is finished.
2) And (3) carrying out spray drying on the slurry after the step 1 is finished, wherein the air inlet temperature is 230 ℃, the air outlet temperature is 95 ℃, the slurry stirring speed is 26HZ, dry powder is obtained, the dry powder is filled into a pot by 4.5kg and enters a nitrogen-filled kiln, the sintering temperature of the kiln is 710 ℃, the sintering time is 8h, the sintered material is conveyed to a jet mill, the crushing frequency is 42HZ, the classification frequency is 38HZ, and the air source pressure is 1.And (3) passing the material through a 350-mesh screen, and demagnetizing by adopting a 2000GS electromagnet to finally obtain a finished product of the lithium iron phosphate cathode material. The particle diameter of the finished product is 1.4 mu m, and the specific surface area is 11m2(g) tap density of 0.86g/cm3。
The products of the above examples and comparative examples were subjected to the performance measurement, and the results are shown in Table 1
(1) The carbon content testing method comprises the following steps: an infrared carbon-sulfur analyzer is adopted, carbon in a sample is heated at high temperature under the oxygen-enriched condition and oxidized into carbon dioxide, the gas enters an absorption cell after being treated, corresponding infrared absorption is carried out, a detector converts the infrared absorption into a signal, and the signal is output through a calculator.
(2) The particle size testing method comprises the following steps: and (3) adopting a laser particle analyzer, adding alcohol into the sample by taking deionized water as a solvent for dispersion, adopting external ultrasonic for 30S, testing, acquiring and outputting results, wherein the particle sizes are different, and the scattering angles are different.
(3) Specific surface area: weighing a certain sample can be performed on a scale by a dynamic or static method.
(4) And (3) performing electric deduction test: weighing active substances, PVDF solution and carbon black in a solid weight ratio of 86:7.5:6.5, uniformly mixing, coating on a current collector, baking for 4 hours, cutting into small wafers, taking a lithium wafer as a negative electrode, taking 1mol/L lithium hexafluorophosphate (EC: DEC volume ratio of 1:1) as electrolyte, adopting a PE single-layer diaphragm, and assembling and fastening electricity in a glove box. The voltage range is 2.0-3.7V by adopting a 1C (160mA) current test.
(5) Testing of compacted density: 5.000g of the powder was weighed and the compacted density was measured under a pressure of 16 KN.
The performance tests are shown in Table 1
TABLE 1
| Carbon content | Particle size | Specific surface area | Buckle 1.0C (2.0-3.7V) | Density of compaction | |
| Example 1 | 2.1％ | 1.8μm | 10.9m2/g | 152mAh/g | 2.64g/cc |
| Example 2 | 1.85％ | 1.5μm | 11.2m2/g | 150mAh/g | 2.68g/cc |
| Example 3 | 2.3％ | 1.46μm | 11.9m2/g | 154mAh/g | 2.60g/cc |
| Example 4 | 2.41％ | 1.37μm | 9.7m2/g | 155mAh/g | 2.51g/cc |
| Comparative example 1 | 2.19％ | 1.4μm | 11m2/g | 157mAh/g | 2.41g/cc |
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A preparation method of a high-compaction and high-capacity lithium iron phosphate positive electrode material is characterized by comprising the following steps:
A) mixing iron oxide, lithium dihydrogen phosphate and a carbon source in a solid phase to obtain a mixture;
B) under the condition of protective atmosphere, carrying out heat treatment on the mixture to obtain a lithium iron phosphate primary seed crystal;
C) mixing and grinding the lithium iron phosphate primary seed crystal, a lithium source, a carbon source and an additive in a liquid phase to obtain slurry;
D) after the slurry is subjected to spray drying, carrying out secondary heat treatment under the condition of protective atmosphere to obtain a lithium iron phosphate process product;
E) and crushing the lithium iron phosphate process product, and then screening and demagnetizing to obtain the high-compaction and high-capacity lithium iron phosphate anode material.
2. The method according to claim 1, wherein the iron oxide is selected from the group consisting of Fe2O3、FeO、Fe3O4One or more of; the particle size of the iron oxide is less than 1 mu m, and the tap density is more than or equal to 4g/cm3The specific surface area is less than or equal to 50m2/g；
The purity of the lithium dihydrogen phosphate is more than or equal to 99 percent, and the water content is less than 0.02 percent;
the carbon source is selected from one or more of glucose, starch, sucrose, phenolic resin, cellulose, citric acid, graphite and carbon tubes.
3. The preparation method according to claim 1, wherein the iron oxide and the lithium dihydrogen phosphate are fed in a molar ratio of Fe element to P element of 1 (0.95-1.0), and the mass of the carbon source is 4-35% of the mass of the iron oxide.
4. The preparation method according to claim 1, wherein the solid phase mixing device used in the solid phase mixing method is selected from a three-dimensional mixer or a high speed mixer, preferably a high speed mixer, the solid phase mixing is performed at low speed and then at high speed, the mixing parameters of the high speed mixer are that the low speed is less than 500PPM, the time is 10-30min, the high speed is more than 1000PPM, and the high speed is 1-5 h.
5. The method of claim 1, wherein the protective atmosphere conditions are selected from one or more of nitrogen, helium, and argon;
the temperature of the heat treatment is 650-800 ℃, and the time is 8-20 h.
6. The method according to claim 1, wherein in step C), the lithium source is selected from one or more of lithium carbonate, lithium hydroxide dihydrate, and lithium nitrate;
the iron phosphate is selected from ferric orthophosphate, dihydrate and lithium iron phosphate or ferric phosphate tetrahydrate, the particle size of the iron phosphate is less than or equal to 9 mu m, and the tap density is 0.6-1.2 g/cm3Specific surface area of 4 to 15m2/g；
The carbon source is one or more of glucose, phenolic resin, starch, sucrose, lipid substances, cellulose, citric acid, graphite and carbon tubes;
the additive is selected from a compound of titanium, a compound of magnesium, a compound of aluminum or a compound of niobium;
the molar ratio of metal elements in the lithium iron phosphate primary seed crystal, the lithium iron phosphate, the lithium source and the additive is 1: (0.1-9): (1.0-1.14): (0.001-0.02);
the weight of the carbon source is 0.5-40% of the weight of the lithium iron phosphate primary seed crystal;
the solvent used for liquid phase mixing is one or more of deionized water, ethanol, acetone and NMP; the dosage of the solvent is 20-65% of the total weight of the solid in the step C);
the stirring speed during the mixing is 15-60HZ, and the stirring time is 0.5-4 h.
7. The method of claim 1, wherein the protective atmosphere conditions are selected from one or more of nitrogen, helium, and argon;
the temperature of the heat treatment is 610-800 ℃, and the time is 5-18 h.
8. The preparation method according to claim 1, wherein the pulverization is selected from jet milling, the pulverization frequency is 15-45 HZ, the classification frequency is 12-60 HZ, and the air source pressure is 0.4-1.5 MPa.
9. The high-compaction high-capacity lithium iron phosphate positive electrode material prepared by the preparation method of any one of claims 1 to 8, wherein the magnetic substance of the lithium iron phosphate positive electrode material is less than or equal to 500PPB, and the particle size is less than or equal to 4 μm.
10. A lithium ion battery comprising the high-compaction, high-capacity lithium iron phosphate positive electrode material of claim 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210169389.7A CN114368737A (en) | 2022-02-23 | 2022-02-23 | High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210169389.7A CN114368737A (en) | 2022-02-23 | 2022-02-23 | High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114368737A true CN114368737A (en) | 2022-04-19 |
Family
ID=81145059
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210169389.7A Pending CN114368737A (en) | 2022-02-23 | 2022-02-23 | High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114368737A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115744875A (en) * | 2023-01-10 | 2023-03-07 | 锂源(深圳)科学研究有限公司 | Method for preparing anode material in situ by seed crystal |
| CN115806283A (en) * | 2022-11-23 | 2023-03-17 | 四川万鹏时代科技股份有限公司 | Preparation method of high-compaction lithium iron phosphate cathode material of lithium ion battery |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014109575A1 (en) * | 2013-01-10 | 2014-07-17 | 주식회사 엘지화학 | Method for producing carbon-coated lithium iron phosphate nanopowder |
| WO2016008455A2 (en) * | 2014-07-17 | 2016-01-21 | 深圳市贝特瑞新能源材料股份有限公司 | Multiple-element composite material for negative electrodes, preparation method therefor, and lithium-ion battery having same |
| CN106744780A (en) * | 2017-03-22 | 2017-05-31 | 广东光华科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN108706564A (en) * | 2018-04-24 | 2018-10-26 | 江西省金锂科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN110127646A (en) * | 2019-06-17 | 2019-08-16 | 桑顿新能源科技(长沙)有限公司 | Lithium iron phosphate positive material and preparation method thereof and battery |
| CN110550615A (en) * | 2019-10-14 | 2019-12-10 | 王敏 | Preparation method of high-energy-density lithium iron phosphate |
| CN112875671A (en) * | 2021-01-25 | 2021-06-01 | 湖北融通高科先进材料有限公司 | Preparation method of high-compaction lithium iron phosphate material and lithium iron phosphate material prepared by method |
| CN113745503A (en) * | 2021-08-04 | 2021-12-03 | 北京泰丰先行新能源科技有限公司 | Preparation method of high-compaction lithium iron phosphate cathode material |
-
2022
- 2022-02-23 CN CN202210169389.7A patent/CN114368737A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2014109575A1 (en) * | 2013-01-10 | 2014-07-17 | 주식회사 엘지화학 | Method for producing carbon-coated lithium iron phosphate nanopowder |
| WO2016008455A2 (en) * | 2014-07-17 | 2016-01-21 | 深圳市贝特瑞新能源材料股份有限公司 | Multiple-element composite material for negative electrodes, preparation method therefor, and lithium-ion battery having same |
| CN106744780A (en) * | 2017-03-22 | 2017-05-31 | 广东光华科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN108706564A (en) * | 2018-04-24 | 2018-10-26 | 江西省金锂科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN110127646A (en) * | 2019-06-17 | 2019-08-16 | 桑顿新能源科技(长沙)有限公司 | Lithium iron phosphate positive material and preparation method thereof and battery |
| CN110550615A (en) * | 2019-10-14 | 2019-12-10 | 王敏 | Preparation method of high-energy-density lithium iron phosphate |
| CN112875671A (en) * | 2021-01-25 | 2021-06-01 | 湖北融通高科先进材料有限公司 | Preparation method of high-compaction lithium iron phosphate material and lithium iron phosphate material prepared by method |
| CN113745503A (en) * | 2021-08-04 | 2021-12-03 | 北京泰丰先行新能源科技有限公司 | Preparation method of high-compaction lithium iron phosphate cathode material |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115806283A (en) * | 2022-11-23 | 2023-03-17 | 四川万鹏时代科技股份有限公司 | Preparation method of high-compaction lithium iron phosphate cathode material of lithium ion battery |
| CN115744875A (en) * | 2023-01-10 | 2023-03-07 | 锂源(深圳)科学研究有限公司 | Method for preparing anode material in situ by seed crystal |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114368737A (en) | High-compaction and high-capacity lithium iron phosphate positive electrode material and preparation method and application thereof | |
| US11450848B2 (en) | Method of preparing lithium ion battery cathode materials | |
| CN101559935B (en) | Lithium iron phosphate cathode material and preparation method thereof | |
| US20110223491A1 (en) | Lithium titanate composite material, preparation method thereof, negative active substance and lithium ion secondary battery containing the same | |
| CN104979541B (en) | A kind of lithium titanate composite material and preparation method thereof | |
| CN114744179B (en) | Sodium ion battery positive electrode material and preparation method and application thereof | |
| US10442699B2 (en) | Method of manufacturing a positive electrode active material for lithium secondary batteries | |
| GB2503138A (en) | Spinel-type lithium manganese-based composite oxide | |
| CN114956203B (en) | Zinc-containing positive electrode material for sodium ion battery and preparation method and application thereof | |
| CN106816581B (en) | A kind of iron manganese phosphate for lithium class material and preparation method thereof and cell size and anode and lithium battery | |
| CN111540901B (en) | Method for preparing lithium iron phosphate (LEP) by using lithium iron phosphate (III) | |
| CN113555544A (en) | Al-Ti-Mg element co-doped and LATP coated high-voltage spinel LNMO positive electrode material and preparation method thereof | |
| CN106935850B (en) | Positive active material, preparation method thereof, battery slurry, positive electrode and lithium battery | |
| CN113964314B (en) | Method for modifying surface of lithium transition metal oxide positive electrode material | |
| CN105514423A (en) | Preparation method of cathode material, cathode material, and battery | |
| CN114899392A (en) | Preparation method of lithium iron phosphate or lithium ferromanganese anode material of lithium ion battery | |
| CN115072694A (en) | Lithium iron phosphate anode material, preparation method thereof and lithium ion battery | |
| EP4216314A1 (en) | Positive electrode material, positive electrode sheet and battery | |
| CN117263254B (en) | Lithium ferrite material and preparation method and application thereof | |
| CN111483995A (en) | Preparation method of lithium iron phosphate | |
| CN114655943B (en) | Lithium iron manganese phosphate composite material, preparation method thereof, positive electrode and lithium ion battery | |
| CN115353085B (en) | Lithium iron phosphate composite material containing lithium supplementing agent, preparation method and application thereof, and battery containing lithium iron phosphate composite material | |
| TWI815629B (en) | Production method of positive electrode and a battery made therefore | |
| CN114497538B (en) | Gradient coated high-performance lithium iron phosphate composite material and preparation method thereof | |
| CN116281929A (en) | Liquid phase demagnetization method of positive electrode material, demagnetization system, positive electrode material 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 | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20220419 |
|
| RJ01 | Rejection of invention patent application after publication |