CN117361478A - Method for preparing lithium iron phosphate from titanium white concentrated slag - Google Patents
Method for preparing lithium iron phosphate from titanium white concentrated slag Download PDFInfo
- Publication number
- CN117361478A CN117361478A CN202311321369.8A CN202311321369A CN117361478A CN 117361478 A CN117361478 A CN 117361478A CN 202311321369 A CN202311321369 A CN 202311321369A CN 117361478 A CN117361478 A CN 117361478A
- Authority
- CN
- China
- Prior art keywords
- iron phosphate
- lithium iron
- solution
- titanium white
- ferrous
- 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 113
- 239000002893 slag Substances 0.000 title claims abstract description 58
- 238000000034 method Methods 0.000 title claims abstract description 39
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 36
- 235000010215 titanium dioxide Nutrition 0.000 title claims abstract description 36
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims abstract description 49
- 239000000243 solution Substances 0.000 claims description 53
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 52
- 238000006243 chemical reaction Methods 0.000 claims description 51
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 42
- 239000000463 material Substances 0.000 claims description 38
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 26
- 229910021645 metal ion Inorganic materials 0.000 claims description 26
- 239000008367 deionised water Substances 0.000 claims description 22
- 229910021641 deionized water Inorganic materials 0.000 claims description 22
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 21
- LZZYPRNAOMGNLH-UHFFFAOYSA-M Cetrimonium bromide Chemical group [Br-].CCCCCCCCCCCCCCCC[N+](C)(C)C LZZYPRNAOMGNLH-UHFFFAOYSA-M 0.000 claims description 21
- 239000000843 powder Substances 0.000 claims description 21
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 20
- 238000001354 calcination Methods 0.000 claims description 18
- 238000001914 filtration Methods 0.000 claims description 18
- 238000000227 grinding Methods 0.000 claims description 18
- 239000004094 surface-active agent Substances 0.000 claims description 16
- 238000001035 drying Methods 0.000 claims description 15
- 238000003756 stirring Methods 0.000 claims description 15
- 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 14
- 239000008103 glucose Substances 0.000 claims description 14
- 238000001027 hydrothermal synthesis Methods 0.000 claims description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 11
- 239000011324 bead Substances 0.000 claims description 10
- 229910052757 nitrogen Inorganic materials 0.000 claims description 10
- 238000001556 precipitation Methods 0.000 claims description 9
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 239000003638 chemical reducing agent Substances 0.000 claims description 8
- 238000011068 loading method Methods 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 238000002156 mixing Methods 0.000 claims description 7
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 claims description 6
- 238000001816 cooling Methods 0.000 claims description 4
- 229960005070 ascorbic acid Drugs 0.000 claims description 3
- 235000010323 ascorbic acid Nutrition 0.000 claims description 3
- 239000011668 ascorbic acid Substances 0.000 claims description 3
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- 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 2
- 229930006000 Sucrose Natural products 0.000 claims description 2
- 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 2
- 238000007664 blowing Methods 0.000 claims description 2
- 238000007865 diluting Methods 0.000 claims description 2
- 125000002791 glucosyl group Chemical group C1([C@H](O)[C@@H](O)[C@H](O)[C@H](O1)CO)* 0.000 claims description 2
- 239000011259 mixed solution Substances 0.000 claims description 2
- 239000002244 precipitate Substances 0.000 claims description 2
- 230000001105 regulatory effect Effects 0.000 claims description 2
- 239000012047 saturated solution Substances 0.000 claims description 2
- 238000012216 screening Methods 0.000 claims description 2
- 239000005720 sucrose Substances 0.000 claims description 2
- 239000012141 concentrate Substances 0.000 claims 9
- 239000012535 impurity Substances 0.000 abstract description 14
- 230000008901 benefit Effects 0.000 abstract description 9
- 238000002360 preparation method Methods 0.000 abstract description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 5
- 230000008569 process Effects 0.000 abstract description 5
- 230000007246 mechanism Effects 0.000 abstract description 2
- 230000002195 synergetic effect Effects 0.000 abstract description 2
- 238000010438 heat treatment Methods 0.000 description 26
- 229910012258 LiPO Inorganic materials 0.000 description 22
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 17
- 235000003891 ferrous sulphate Nutrition 0.000 description 13
- 239000011790 ferrous sulphate Substances 0.000 description 13
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 13
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 13
- 229910052744 lithium Inorganic materials 0.000 description 13
- 239000010936 titanium Substances 0.000 description 13
- 239000010453 quartz Substances 0.000 description 12
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 11
- 229910052719 titanium Inorganic materials 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 10
- 239000007774 positive electrode material Substances 0.000 description 9
- 239000002994 raw material Substances 0.000 description 9
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 8
- 239000013078 crystal Substances 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 7
- 239000011572 manganese Substances 0.000 description 7
- 239000000706 filtrate Substances 0.000 description 6
- 230000003301 hydrolyzing effect Effects 0.000 description 6
- 239000011777 magnesium Substances 0.000 description 6
- 229920002635 polyurethane Polymers 0.000 description 6
- 239000004814 polyurethane Substances 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 238000007789 sealing Methods 0.000 description 6
- 239000002699 waste material Substances 0.000 description 6
- 229910010710 LiFePO Inorganic materials 0.000 description 5
- 238000002441 X-ray diffraction Methods 0.000 description 5
- 229910052748 manganese Inorganic materials 0.000 description 5
- 229910052698 phosphorus Inorganic materials 0.000 description 5
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 4
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 4
- 238000005054 agglomeration Methods 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 239000010405 anode material Substances 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000012467 final product Substances 0.000 description 3
- 229910000398 iron phosphate Inorganic materials 0.000 description 3
- SURQXAFEQWPFPV-UHFFFAOYSA-L iron(2+) sulfate heptahydrate Chemical compound O.O.O.O.O.O.O.[Fe+2].[O-]S([O-])(=O)=O SURQXAFEQWPFPV-UHFFFAOYSA-L 0.000 description 3
- 229910001416 lithium ion Inorganic materials 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- 238000003801 milling Methods 0.000 description 3
- 238000012795 verification Methods 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000002484 cyclic voltammetry Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- DVATZODUVBMYHN-UHFFFAOYSA-K lithium;iron(2+);manganese(2+);phosphate Chemical compound [Li+].[Mn+2].[Fe+2].[O-]P([O-])([O-])=O DVATZODUVBMYHN-UHFFFAOYSA-K 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 102100030310 5,6-dihydroxyindole-2-carboxylic acid oxidase Human genes 0.000 description 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- 239000005955 Ferric phosphate Substances 0.000 description 1
- 101000773083 Homo sapiens 5,6-dihydroxyindole-2-carboxylic acid oxidase Proteins 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 239000002019 doping agent Substances 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 229940032958 ferric phosphate Drugs 0.000 description 1
- 239000012761 high-performance material Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000001095 inductively coupled plasma mass spectrometry Methods 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- XBDUTCVQJHJTQZ-UHFFFAOYSA-L iron(2+) sulfate monohydrate Chemical compound O.[Fe+2].[O-]S([O-])(=O)=O XBDUTCVQJHJTQZ-UHFFFAOYSA-L 0.000 description 1
- 229910021506 iron(II) hydroxide Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 1
- NCNCGGDMXMBVIA-UHFFFAOYSA-L iron(ii) hydroxide Chemical compound [OH-].[OH-].[Fe+2] NCNCGGDMXMBVIA-UHFFFAOYSA-L 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 description 1
- 229910052808 lithium carbonate Inorganic materials 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- 231100000956 nontoxicity Toxicity 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011148 porous material Substances 0.000 description 1
- 239000012429 reaction media Substances 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 239000001038 titanium pigment Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/58—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
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- 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
- C01P2004/10—Particle morphology extending in one dimension, e.g. needle-like
-
- 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
-
- 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
- C01P2006/80—Compositional purity
-
- 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
Abstract
The invention discloses a method for preparing lithium iron phosphate from titanium white concentrated slag, and relates to the technical field of lithium iron phosphate preparation. Aiming at the prior art, the invention develops a process method for preparing the lithium iron phosphate with practical value by comprehensively considering the resource comprehensive utilization of the titanium white concentrated ferrous slag and the production of the lithium iron phosphate in order to solve the resource utilization of the ferrous slag, develop the influence mechanism of various impurity elements on the lithium iron phosphate and the synergistic benefit of various elements, and effectively improve the electrochemical performance of the lithium iron phosphate product.
Description
Technical Field
The invention relates to the technical field of preparation of lithium iron phosphate, in particular to a method for preparing lithium iron phosphate from titanium white concentrated slag.
Background
A large amount of three wastes (waste acid with concentration of 20-25%) are generated in the process of producing titanium pigment, and the waste acid is treatedMainly uses the concentrated ferrous slag or ferrous yellow as the main components, namely ferrous sulfate monohydrate and Ti 4+ 、Mn 2+ 、Mg 2+ 、Al 3+ And various impurities are difficult to directly utilize, and most of the impurities can be directly stacked after acid-base neutralization, so that the economic benefit is greatly affected.
Lithium iron phosphate is paid attention as a new generation lithium battery anode material, and LiFePO is developed along with the development of the social lithium battery industry 4 The material is regarded as a new generation lithium ion anode material due to the advantages of safety, no toxicity, environmental protection, high specific capacity and the like, while the ferrous slag has low cost and stable source, and a plurality of scholars adopt titanium white byproduct ferrous sulfate and ferrous slag as LiFePO 4 Although the presence of impurities affects the comprehensive utilization of the ferrocyanide slag, researchers have studied that small amounts of metallic elements such as Mn, mg, ti and the like act as dopants to dope LiFePO 4 The electrochemical performance of the battery is beneficial to improvement, so that ferrous slag containing various impurity elements such as the ferrous slag can change waste into valuable, thereby converting a large amount of industrial ferrous slag into LiFePO with higher added value 4 Positive electrode materials, which are problems to be solved. A method for preparing lithium iron phosphate from a titanium white byproduct ferrous sulfate has been disclosed in the prior art. The technical scheme disclosed in the patent application document with the publication number of CN 114538404A is as follows: taking ferrous sulfate heptahydrate as an iron source, adding sulfuric acid to adjust the pH value, adding iron powder to stir and react, adding ferric phosphate or lithium iron phosphate waste powder into the solution, heating, stirring, cooling and filtering to obtain a purified ferrous sulfate solution; adding phosphoric acid and lithium hydroxide solution into an autoclave in a parallel flow mode, adding ferrous sulfate solution, heating, reacting, cooling, filtering and drying to obtain lithium iron phosphate powder. In another patent of the invention of publication No. CN108101016B, a titanium white byproduct ferrous sulfate iron source is used, sodium sulfide is used for removing impurities, the iron phosphate is obtained by reacting with phosphoric acid, then the iron phosphate is mixed with lithium carbonate for grinding, and the mixture is calcined at a high temperature under the protection of nitrogen gas to obtain the lithium iron phosphate material. The technical scheme disclosed in the patent application document of the publication number CN 113968578A is as follows: preparation of sulfuric acid by mixing titanium white byproduct ferrous sulfateAnd adding iron powder into the ferrous solution to reduce ferric iron, adjusting pH by ferrous hydroxide to remove titanium, and oxidizing with phosphoric acid and hydrogen peroxide to synthesize an iron phosphate product.
However, the ferrous slag or the yellow ferrous iron is not directly adopted in the preparation of the ferrous sulfate used as the raw material in the prior art, and the ferrous slag or the yellow ferrous iron is further purified to be ferrous sulfate for use. Although the ferrous slag and the ferrous sulfate are not substantially different, the impurity content of the ferrous slag is larger and more difficult to process, and the ferrous slag cannot be applied to the process for preparing the lithium iron phosphate, the prior research on doping metal impurities into the lithium iron phosphate material is less, but the production research on doping metal contained in the ferrous slag into the lithium iron phosphate material has a large research space, and meanwhile, the self-doping effect and the influence of the self-doping effect on the structure, the morphology and the performance of the material have larger research value.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for preparing lithium iron phosphate from titanium white concentrated slag, which aims to solve the technical problem that the prior art cannot directly use ferrous slag as a raw material to prepare lithium iron phosphate.
The technical scheme adopted by the invention is as follows:
a method for preparing lithium iron phosphate from titanium white concentrated slag comprises the following specific steps:
(1) Dissolving titanium white ferrous slag in deionized water to prepare a saturated solution, adding phosphoric acid to adjust the pH value to 1.5-2, stirring, filtering to remove insoluble matters to obtain a ferrous solution, and standing for later use;
(2) Dissolving lithium hydroxide in deionized water, diluting 85% phosphoric acid, and adding the lithium hydroxide and the phosphoric acid into a reaction kettle in a parallel flow mode to perform stirring reaction to form white precipitate; adding surfactant solution at the same time in the feeding reaction;
(3) Adding a reducing agent into the ferrous solution prepared in the step (1), adding the reducing agent into the solution obtained in the step (2), stirring to completely mix the ferrous solution, the solution is regulated to the pH value again after the mixing reaction is finished to ensure that metal ions are completely precipitated, the solution is gray, dark green or black at the moment, and then carrying out hydrothermal reaction, filtering, washing and drying to obtain metal ion doped lithium iron phosphate powder;
(4) Mixing the lithium iron phosphate powder obtained in the step (3) with a carbon source and grinding;
(5) And loading the ground material into a Dan Yingxia body, calcining under the protection of nitrogen, cooling by adopting nitrogen blowing, and screening to obtain the carbon-coated lithium iron phosphate material.
Preferably, in the step (2), the surfactant is cetyl trimethyl ammonium bromide, and the feeding amount of the surfactant is 1-3% of the total mass of the lithium hydroxide and phosphoric acid mixed solution.
Preferably, in the step (3), the molar ratio of iron to phosphorus to lithium is 1:1:3.
preferably, in the step (3), the reducing agent is glucose or ascorbic acid, and the feeding amount of the reducing agent is 1-5% of the mass of the ferrous solution.
Preferably, in the step (3), the hydrothermal reaction temperature is 180-190 ℃ and the reaction time is 12h.
Preferably, in step (3), the pH of the solution is again adjusted to pH1.5-4.5 at the end of the mixing reaction to ensure complete precipitation of the various metal ions, at which time the solution is grey, greenish black or black.
More preferably, the pH of the solution is readjusted to a pH of 2.5-3.5.
Preferably, in the step (4), the carbon source is one of glucose, sucrose and graphene, and the input amount of the carbon source accounts for 5-10% of the mass of the lithium iron phosphate powder.
Preferably, in step (4), the milling is carried out in a ball mill, the milling balls being zirconia beads, the volume ratio of zirconia beads to milling stock being 1:1.
Preferably, in step (5), the calcination temperature is 750-800 ℃ and the calcination time is 3 hours.
In summary, compared with the prior art, the invention has the following advantages and beneficial effects:
1. aiming at the prior art, the invention develops a process method for preparing the lithium iron phosphate with practical value by comprehensively considering the resource comprehensive utilization of the titanium white concentrated ferrous slag and the production of the lithium iron phosphate in order to solve the resource utilization of the ferrous slag, develop the material innovation for preparing the lithium iron phosphate, explore the influence mechanism of various impurity elements on the lithium iron phosphate and the synergistic benefit of various elements, and improve the electrochemical performance of the lithium iron phosphate product.
2. The invention prepares the lithium iron phosphate material by using the titanium white ferrous slag, is a material innovation from the preparation raw materials, and mostly adopts ferrous sulfate heptahydrate to prepare lithium iron phosphate at present, and in a plurality of methods for preparing the lithium iron phosphate, scholars change the orbit of lithium ions by doping metal ions when modifying the material, and change LiFePO (lithium iron phosphate) 4 The crystal grain size forms lattice defects such as holes, improves the conductivity and the diffusion rate of lithium ions, and finally improves LiFePO 4 Electrochemical properties of the material; the selected raw material ferroslag contains metal ions such as titanium, manganese, magnesium and the like, and is matched with specific preparation process and conditions, the metal ions are not required to be introduced externally, the self-doping of the lithium iron phosphate prepared from the raw material is more economical in cost, and the raw material is not required to be subjected to impurity removal, wherein Mn ions replace Fe to form the lithium iron manganese phosphate material, and the lithium iron manganese phosphate material can promote Li + Diffusion improves the electrical conductivity inside the crystal.
3. The hydrothermal synthesis method is a method for producing a required product by taking aqueous solution as a reaction medium and carrying out chemical reaction on raw material substances in a closed container under high temperature and high pressure conditions. As one of the liquid phase synthesis methods, the method has the characteristics of rapidness, simplicity and low cost, and the synthesized particles have high purity, good dispersibility, good crystal form and controllability; compared with a high-temperature solid phase method, the hydrothermal method has the advantages of short reaction time, high product purity, easily controlled granularity and no need of inert atmosphere in industrial production.
4. From the aspect of performance, the invention takes ferrous slag as an iron source, liOH as a lithium source and H 3 PO 4 As a phosphorus source, a hydrothermal synthesis one-step preparation method is adopted, and better LiFePO is obtained by synthesis at the crystallization time of 10h and the temperature of 175 DEG C 4 And the pH is again adjusted to 1.5 to 4.5, preferably pH2.5 to 3.5, after the reaction is completed, ensuring complete precipitation of the metal ions.To the component content by XRF, ICP-MS analysis: the Fe content is 33 percent, the P content is 19 percent, the Li content is 4.84 percent, the Li content is 5.72 percent, and the content accords with LiFePO 4 National standard requirements. The metal ions Mg, mn and Ti of the ferrocyanide slag are doped into the material, while other impurity elements are not doped into the ferrocyanide slag, and the doped metal ions have certain influence on the structure and performance of the prepared lithium iron phosphate product. The XRD analysis shows that the product has olivine crystal structure, the unit cell parameters are reduced, the metal elements of Mn and Mg are doped, and certain Fe is occupied 2+ Has a certain influence on the electrochemical performance of the lithium iron phosphate. Specific surface area 7.3862m from BET test 2 And/g, average pore diameter 15.15nm. Observation of LiFePO by SEM 4 The morphology of the lithium iron phosphate prepared by the ferrous slag one-step method is similar to that of a sphere, some of the lithium iron phosphate is a blocky monocrystalline flake, and the morphology of a sample prepared from ferrous sulfate is regular in a prismatic rod-shaped structure.
5. The method for preparing the lithium iron phosphate from the titanium white ferrous slag has the advantages of simple and controllable process, low cost, safety and environmental protection, and the prepared lithium iron phosphate powder is used as a lithium battery anode material by carrying out hydrothermal reaction on the lithium iron phosphate and the lithium hydroxide as an iron source, has excellent performance, realizes the effective utilization of the ferrous slag obtained by concentrating the titanium white waste acid while preparing the high-performance material, and improves the economic benefit.
Drawings
FIG. 1 shows XRD patterns of lithium iron phosphate prepared in examples 1 to 3 and comparative examples 1 to 3, wherein the left side of the patterns is the XRD patterns of lithium iron phosphate prepared in examples 1 to 3 and the right side of the patterns is the XRD patterns of lithium iron phosphate prepared in comparative examples 1 to 3, and the lowermost curve of the two patterns is lithium iron phosphate LiPO 4 Characteristic peak curves of standard cards;
fig. 2 is an SEM image of lithium iron phosphate materials prepared in examples 1 to 3 and comparative examples 1 to 3, wherein the upper row corresponds to examples 1 to 3 in order from left to right, and the lower row corresponds to examples 1 to 3 in order from left to right;
FIG. 3 shows a different lithium iron phosphate LiPO 4 The positive electrode material has a cyclic voltammogram at 1 mV/s.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings, and examples and verification examples. It should be understood that the specific embodiments and examples of verification described herein are intended to be illustrative of the invention and are not intended to be limiting of the invention, i.e., the embodiments described are merely some, rather than all, of the embodiments of the invention.
The word "embodiment" as used herein does not necessarily mean that any embodiment described as "exemplary" is preferred or advantageous over other embodiments. Performance index testing in this method example unless otherwise specified, conventional testing methods in the art were employed. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure.
Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs; other raw materials, reagents, test methods and technical means not specifically mentioned in the present invention refer to raw materials and reagents commonly used by those skilled in the art, and experimental methods and technical means commonly employed.
Example 1
The embodiment provides a method for preparing lithium iron phosphate by adopting titanium white concentrated slag in one step, which comprises the following specific steps:
(1) Taking 100g of ferrous slag, adding 150ml of deionized water solution, heating to 60 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 50ml of prepared 1.5% glucose solution;
(2) 40g of lithium hydroxide is weighed and stirred and dissolved in 100ml of deionized water; then 16g of phosphoric acid with the mass fraction of 85% is weighed and dissolved in 100ml of deionized water, the phosphoric acid is fed into a reaction kettle in a parallel flow mode, stirred and reacted at 30 ℃, white precipitation occurs at the moment, and 10ml of surfactant CTAB with the mass fraction of 1% is prepared and added into a reaction system;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green, and stirring for 0.5h at 30 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 10h for hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and glucose (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1:1, grinding for 1h at 600 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 400 ℃, preserving heat for 1h, then introducing nitrogen, heating to 750 ℃, preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 1.
In this example, the final product content was analyzed by ICP and XRF, and it was found that Fe was 33%, P was 19%, li was 4.84%, metal ion Mg was 1%, mn was 0.6%, and Ti was 0.06%.
Example 2
The embodiment provides a method for preparing lithium iron phosphate by adopting titanium white concentrated slag in one step, which comprises the following specific steps:
(1) Taking 140g of ferrous slag, adding 300ml of deionized water solution, heating to 50 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 60ml of prepared 2% glucose solution;
(2) 63g of lithium hydroxide is weighed and stirred and dissolved in 150ml of deionized water; then 28.8g of phosphoric acid with the mass fraction of 85% is weighed and dissolved in 150ml of deionized water, and is fed into a reaction kettle in a parallel flow mode, stirred and reacted at 45 ℃, white precipitation occurs at the moment, and 20ml of surfactant CTAB with the mass fraction of 1.5% is prepared and added into a reaction system;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green at the moment, and stirring for 0.5h at 45 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 12h of hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and glucose (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1:1.5, grinding for 1h at 650 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 400 ℃, preserving heat for 1h, then introducing nitrogen, heating to 800 ℃, preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 2.
In this example, the final product content was analyzed by ICP and XRF, and was found to be 34% Fe, 19% P, 5.72% Li, 1% metal ion Mg, 0.4% Mn, and 0.07% Ti.
Example 3
The embodiment provides a method for preparing lithium iron phosphate by adopting titanium white concentrated slag in one step, which comprises the following specific steps:
(1) Taking 75g of ferrous slag, adding 150ml of deionized water solution, heating to 60 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 50ml of prepared 1.5% ascorbic acid solution;
(2) 38g of lithium hydroxide is weighed and stirred and dissolved in 100ml of deionized water; then 16g of phosphoric acid with the mass fraction of 85% is weighed and dissolved in 100ml of deionized water, the phosphoric acid is fed into a reaction kettle in a parallel flow mode, and stirred and reacted at 50 ℃, white precipitation occurs at the moment, and 10ml of surfactant CTAB with the mass fraction of 2% is prepared and added into a reaction system;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green, and stirring for 0.5h at 50 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 10h for hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and graphene (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1.1:1, grinding for 1h at 700 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 350 ℃, preserving heat for 1h, then introducing nitrogen, heating to 800 ℃ and preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 3.
In this example, the final product content was analyzed by ICP and XRF, and was found to be 34% Fe, 20% P, 5.03% Li, and 0.03% metal ion Ti.
Comparative example 1
The comparative example provides a method for preparing lithium iron phosphate by adopting a titanium white concentrated slag one-step method, which comprises the following specific steps:
(1) Taking 100g of ferrous sulfate heptahydrate, adding 150ml of deionized water solution, heating to 60 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 50ml of prepared 1.5% glucose solution;
(2) 40g of lithium hydroxide is weighed and stirred and dissolved in 100ml of deionized water; then 16g of phosphoric acid with the mass fraction of 85% is weighed and dissolved in 100ml of deionized water, the phosphoric acid is fed into a reaction kettle in a parallel flow mode, stirred and reacted at 30 ℃, white precipitation occurs at the moment, and 10ml of surfactant CTAB with the mass fraction of 1% is prepared and added into a reaction system;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green, and stirring for 0.5h at 30 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 10h for hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and glucose (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1:1, grinding for 1h at 600 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 400 ℃, preserving heat for 1h, then introducing nitrogen, heating to 750 ℃, preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 4.
Comparative example 2
The comparative example provides a method for preparing lithium iron phosphate by adopting a titanium white concentrated slag one-step method, which comprises the following specific steps:
(1) Taking 100g of ferrous slag, adding 150ml of deionized water solution, heating to 60 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 50ml of prepared 1.5% glucose solution;
(2) 40g of lithium hydroxide is weighed and stirred and dissolved in 100ml of deionized water; then weighing 16g of 85% phosphoric acid by mass fraction, dissolving in 100ml of deionized water, feeding into a reaction kettle in a parallel flow mode, and stirring for reaction at 30 ℃, wherein white precipitation occurs;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green, and stirring for 0.5h at 30 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 10h for hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and glucose (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1:1, grinding for 1h at 600 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 400 ℃, preserving heat for 1h, then introducing nitrogen, heating to 750 ℃, preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 5.
Comparative example 3
The comparative example provides a method for preparing lithium iron phosphate by adopting a titanium white concentrated slag one-step method, which comprises the following specific steps:
(1) Taking 100g of ferrous slag, adding 150ml of deionized water solution, heating to 60 ℃, adding phosphoric acid to adjust the pH to about 1.5, hydrolyzing a part of titanium, filtering to remove insoluble substances, taking filtrate, and adding 50ml of prepared 1.5% glucose solution;
(2) 40g of lithium hydroxide is weighed and stirred and dissolved in 100ml of deionized water; then, 16g of phosphoric acid with the mass fraction of 85% is weighed and dissolved in 100ml of deionized water, and is fed into a reaction kettle in a parallel flow mode, stirred and reacted at 30 ℃, white precipitation occurs at the moment, and 10ml of SDS with the mass fraction of 1% is prepared and added into a reaction system;
(3) Dropwise adding the ferrous solution prepared in the step (1) into a reaction kettle, gradually changing the solution from white to dark green, and stirring for 0.5h at 30 ℃, wherein the molar ratio of the ferrophosphorus to the lithium is 1:1:3, a step of;
(4) Transferring the reaction kettle in the step (3) into a drying box in a sealing way, heating to 175 ℃, and preserving heat for 10h for hydrothermal reaction; after the reaction is finished and fully cooled, opening the reaction kettle, filtering, washing and drying materials to obtain lithium iron phosphate powder;
(5) Pouring the lithium iron phosphate powder and glucose (accounting for 5 percent of the total weight of the lithium iron phosphate) in the step (4) into a polyurethane tank, and adding zirconia beads according to the volume ratio of 1:1, grinding for 1h at 600 r/min;
(6) And (3) loading the materials subjected to grinding in the step (5) into a quartz box, feeding the quartz box into a tube furnace for calcination, heating to 400 ℃, preserving heat for 1h, then introducing nitrogen, heating to 750 ℃, preserving heat for 2h, and obtaining the metal ion-containing carbon-doped coated lithium iron phosphate material after the calcination is finished, and naming a sample 6.
The samples prepared in examples 1 to 3 and comparative examples 1 to 3 were analyzed, and their XRD patterns are shown in FIG. 1. As can be seen from FIG. 1, lithium iron phosphate LiPO was prepared when the surfactant CTAB was added in amounts of 1%, 1.5% and 2% of the reaction system, respectively 4 Can be the same as lithium iron phosphate LiPO 4 The characteristic peaks of the standard cards correspond to each other, and the conclusion can be drawn that the lithium iron phosphate LiPO is successfully prepared by different addition amounts of the surfactant CATB 4 And a positive electrode material. When the CTAB addition amount is 1%, lithium iron phosphate LiPO 4 The characteristic peaks of the lithium iron phosphate LiPO are sharp and have few impurity peaks, which indicates that the prepared lithium iron phosphate LiPO 4 Has good crystal form and is basically similar to pure substance for preparing lithium iron phosphate LiPO 4 The structure of the positive electrode material is consistent. With the increase of the CTAB addition amount, lithium iron phosphate LiPO 4 The characteristic peak intensity of (2) is reduced and the impurity peak is increased, which means that more metal ions participate in the reaction, resulting in lithium iron phosphate LiPO 4 The structure and crystal form are slightly changed. When CTAB is not added, the prepared lithium iron phosphate LiPO 4 The positive electrode material has a lot of impurity peaks due to lithium iron phosphate LiPO 4 During the generation, other metal ions are wrapped due to agglomeration phenomenon, so that lithium iron phosphate LiPO is caused 4 The crystal form of (a) is changed. Secondly, adding a proper amount of SDS into lithium iron phosphate LiPO prepared from titanium white slag 4 Plays a good role in dispersing, and is properly doped with a little metal ions such as Mn, mg, ti, and the like on the premise of not affecting the whole structure and the crystal form.
The SEM diagram is shown in FIG. 2, and the lithium iron phosphate LiPO is prepared according to the addition amounts of the surfactant CTAB of 1%, 1.5% and 2% respectively 4 As can be seen from the electron microscope of (2), when the addition amount of the surfactant CTAB was 1%, the lithium iron phosphate LiPO 4 Is olive-shaped and is matched with standard lithium iron phosphate LiPO 4 The structure is consistent, and when the addition amount of the surfactant CTAB is 1.5 percent and 2 percent, the lithium iron phosphate LiPO 4 Different degrees of agglomeration occurred and therefore the surface additive CTAB was most suitably 1%. Pure ferrous sulfate FeSO 4 Lithium iron phosphate LiPO prepared by adding 1% CTAB 4 The positive electrode material was olive-shaped with no significant agglomeration. Lithium iron phosphate LiPO prepared by adding 1% SDS into titanium white slag 4 The positive electrode material is rod-shaped, and materials formed by other metal ions can be obviously adhered together, so that the positive electrode material is self-doped with Mn, mg, ti and other metal ions. Lithium iron phosphate LiPO prepared from titanium white slag without adding surfactant 4 The positive electrode material has serious agglomeration phenomenon and is in a block shape.
Sample 1 and pure ferrous sulfate FeSO were selected at a CTAB addition of 1% 4 Sample 4 to which 1% CTAB was added and the amount of CTAB addedSample 5 at 0% was subjected to cyclic voltammetry, and the test results are shown in FIG. 3. It is clear that sample 5 was poor in effect, and sample 1 at 1% CTAB addition and pure ferrous sulfate FeSO 4 Sample 4 with 1% CTAB added is slightly better than the sample, indicating that the CTAB addition is 1% + reaction of the ferrous slag and is not inferior to pure ferrous sulfate FeSO 4 。
The above examples and verification examples only represent specific embodiments of the present application, which are described more specifically and in detail, but are not to be construed as limiting the scope of the present application. It should be noted that, for those skilled in the art, several variations and modifications can be made without departing from the technical solution of the present application, which fall within the protection scope of the present application.
Claims (10)
1. A method for preparing lithium iron phosphate from titanium white concentrated slag is characterized by comprising the following specific steps:
(1) Dissolving titanium white ferrous slag in deionized water to prepare a saturated solution, adding phosphoric acid to adjust the pH value to 1.5-2, stirring, filtering to remove insoluble matters to obtain a ferrous solution, and standing for later use;
(2) Dissolving lithium hydroxide in deionized water, diluting 85% phosphoric acid, and adding the lithium hydroxide and the phosphoric acid into a reaction kettle in a parallel flow mode to perform stirring reaction to form white precipitate; adding surfactant solution at the same time in the feeding reaction;
(3) Adding a reducing agent into the ferrous solution prepared in the step (1), adding the reducing agent into the solution obtained in the step (2), stirring to completely mix the ferrous solution, the solution is regulated to the pH value again after the mixing reaction is finished to ensure that metal ions are completely precipitated, the solution is gray, dark green or black at the moment, and then carrying out hydrothermal reaction, filtering, washing and drying to obtain metal ion doped lithium iron phosphate powder;
(4) Mixing the lithium iron phosphate powder obtained in the step (3) with a carbon source and grinding;
(5) And loading the ground material into a Dan Yingxia body, calcining under the protection of nitrogen, cooling by adopting nitrogen blowing, and screening to obtain the carbon-coated lithium iron phosphate material.
2. The method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (2), the surfactant is cetyl trimethyl ammonium bromide, and the feeding amount of the surfactant is 1-3% of the total mass of the mixed solution of lithium hydroxide and phosphoric acid.
3. The method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (3), the molar ratio of lithium iron phosphate is 1:1:3.
4. the method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (3), the reducing agent is glucose or ascorbic acid, and the feeding amount of the reducing agent is 1-5% of the mass of the ferrous solution.
5. The method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (3), the hydrothermal reaction temperature is 180-190 ℃ and the reaction time is 12 hours.
6. The method for preparing lithium iron phosphate from the titanium white concentrate slag according to claim 1, wherein in the step (3), the pH value of the solution is adjusted again to be pH1.5-4.5 after the mixing reaction is finished, so that the precipitation of various metal ions is ensured to be complete, and the solution is gray, dark green or black.
7. The method for preparing lithium iron phosphate from the titanium white concentrate slag according to claim 6, wherein the pH value of the solution is adjusted to be pH2.5-3.5 again.
8. The method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (4), the carbon source is one of glucose, sucrose and graphene, and the input amount of the carbon source is 5-10% of the mass of the lithium iron phosphate powder.
9. The method for preparing lithium iron phosphate from titanium white concentrate slag according to claim 1, wherein in the step (4), grinding is performed in a ball mill, the grinding balls are zirconia beads, and the volume ratio of the zirconia beads to the grinding material is 1:1.
10. The method for preparing lithium iron phosphate from the titanium white concentrate slag according to claim 1, wherein in the step (5), the calcination temperature is 750-800 ℃ and the calcination time is 3 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311321369.8A CN117361478A (en) | 2023-10-12 | 2023-10-12 | Method for preparing lithium iron phosphate from titanium white concentrated slag |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311321369.8A CN117361478A (en) | 2023-10-12 | 2023-10-12 | Method for preparing lithium iron phosphate from titanium white concentrated slag |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117361478A true CN117361478A (en) | 2024-01-09 |
Family
ID=89401656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311321369.8A Pending CN117361478A (en) | 2023-10-12 | 2023-10-12 | Method for preparing lithium iron phosphate from titanium white concentrated slag |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117361478A (en) |
-
2023
- 2023-10-12 CN CN202311321369.8A patent/CN117361478A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101821197B (en) | Iron(III) orthophosphate for li ion accumulators | |
| US8574518B2 (en) | Production of iron orthophosphate | |
| CN112645299A (en) | Preparation method and application of iron phosphate | |
| EP4023610A1 (en) | Wet synthesis method for ncma high-nickel quaternary precursor | |
| CN107522188B (en) | The preparation method of nanometer spherical iron phosphate and nano ferric phosphate, LiFePO4 and the lithium battery prepared by this method | |
| CN113277489A (en) | Method for preparing high-purity iron phosphate by using ferrophosphorus waste | |
| US20240021904A1 (en) | Recycling method and use of lithium iron phosphate (lfp) waste | |
| CN111916724A (en) | Preparation method and application of washing-free high-nickel monocrystal nickel cobalt lithium manganate positive electrode material | |
| WO2022242184A1 (en) | Doped iron phosphate, and preparation method therefor and application thereof | |
| CN104743537A (en) | Preparation method for lithium iron phosphate/carbon composite positive material with high multiplying power | |
| CN113772650A (en) | Preparation method and application of lithium iron phosphate | |
| GB2621302A (en) | Nanometer sheet-like iron phosphate, preparation method therefor and use thereof | |
| CN110482515B (en) | Preparation method of low-cost lithium iron phosphate | |
| Jiang et al. | Recovery of iron from titanium white waste for the preparation of LiFePO4 battery | |
| CN114572951A (en) | Doped iron phosphate and preparation method and application thereof | |
| CN108557792A (en) | A kind of preparation method of cladded type iron manganese phosphate | |
| CN112573497A (en) | Method for preparing iron phosphate by using ferric oxide | |
| CN112725621A (en) | Method for separating nickel, cobalt and manganese from waste lithium battery based on carbonate solid-phase conversion method | |
| CN117361478A (en) | Method for preparing lithium iron phosphate from titanium white concentrated slag | |
| CN115863570A (en) | Preparation method of sodium ferric sulfate cathode material | |
| CN115974036A (en) | Spherical lithium ferric manganese phosphate nano-particles and preparation method thereof | |
| CN115818601A (en) | Titanium-doped battery-grade iron phosphate and preparation method thereof | |
| CN115196609A (en) | Method for recovering iron phosphate from lithium iron phosphate lithium extraction slag and application thereof | |
| JP7219756B2 (en) | Uniform introduction of titanium into solid materials | |
| CN114162798B (en) | Preparation method for improving specific surface area of ferric phosphate |
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 |