CN114772571A - Preparation method of anhydrous iron phosphate and preparation method of lithium iron phosphate carbon composite material - Google Patents
Preparation method of anhydrous iron phosphate and preparation method of lithium iron phosphate carbon composite material Download PDFInfo
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- CN114772571A CN114772571A CN202210445065.1A CN202210445065A CN114772571A CN 114772571 A CN114772571 A CN 114772571A CN 202210445065 A CN202210445065 A CN 202210445065A CN 114772571 A CN114772571 A CN 114772571A
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- Prior art keywords
- iron phosphate
- phosphate
- lithium
- composite material
- drying
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- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 title claims abstract description 65
- 229910000398 iron phosphate Inorganic materials 0.000 title claims abstract description 51
- 239000002131 composite material Substances 0.000 title claims abstract description 31
- ZTOZIUYGNMLJES-UHFFFAOYSA-K [Li+].[C+4].[Fe+2].[O-]P([O-])([O-])=O Chemical compound [Li+].[C+4].[Fe+2].[O-]P([O-])([O-])=O ZTOZIUYGNMLJES-UHFFFAOYSA-K 0.000 title claims abstract description 25
- 238000002360 preparation method Methods 0.000 title claims abstract description 25
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims abstract description 28
- 230000032683 aging Effects 0.000 claims abstract description 24
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 22
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 claims abstract description 22
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 19
- 238000005245 sintering Methods 0.000 claims abstract description 16
- 239000002245 particle Substances 0.000 claims abstract description 8
- 230000018044 dehydration Effects 0.000 claims abstract description 4
- 238000006297 dehydration reaction Methods 0.000 claims abstract description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 44
- 229910019142 PO4 Inorganic materials 0.000 claims description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 29
- 238000001035 drying Methods 0.000 claims description 27
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 22
- 239000008367 deionised water Substances 0.000 claims description 21
- 229910021641 deionized water Inorganic materials 0.000 claims description 21
- 239000010452 phosphate Substances 0.000 claims description 21
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 21
- 229910052742 iron Inorganic materials 0.000 claims description 18
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 17
- -1 iron ion Chemical class 0.000 claims description 17
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 16
- 238000003825 pressing Methods 0.000 claims description 16
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 15
- 239000011164 primary particle Substances 0.000 claims description 15
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 12
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 12
- 238000000227 grinding Methods 0.000 claims description 11
- 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 10
- 239000012065 filter cake Substances 0.000 claims description 10
- 239000000706 filtrate Substances 0.000 claims description 10
- 239000008103 glucose Substances 0.000 claims description 10
- 239000000843 powder Substances 0.000 claims description 10
- 238000005406 washing Methods 0.000 claims description 10
- 229910052744 lithium Inorganic materials 0.000 claims description 9
- 230000003647 oxidation Effects 0.000 claims description 9
- 238000007254 oxidation reaction Methods 0.000 claims description 9
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 8
- 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 8
- 229930006000 Sucrose Natural products 0.000 claims description 8
- 239000006227 byproduct Substances 0.000 claims description 8
- 239000003337 fertilizer Substances 0.000 claims description 8
- 239000012535 impurity Substances 0.000 claims description 8
- 238000001556 precipitation Methods 0.000 claims description 8
- 239000002002 slurry Substances 0.000 claims description 8
- 239000005720 sucrose Substances 0.000 claims description 8
- 239000004408 titanium dioxide Substances 0.000 claims description 8
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 7
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 7
- 238000001816 cooling Methods 0.000 claims description 7
- 238000001914 filtration Methods 0.000 claims description 7
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- 239000002243 precursor Substances 0.000 claims description 7
- 238000001694 spray drying Methods 0.000 claims description 7
- YUWBVKYVJWNVLE-UHFFFAOYSA-N [N].[P] Chemical compound [N].[P] YUWBVKYVJWNVLE-UHFFFAOYSA-N 0.000 claims description 6
- 239000000654 additive Substances 0.000 claims description 6
- 230000000996 additive effect Effects 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 6
- 230000007062 hydrolysis Effects 0.000 claims description 6
- 238000006460 hydrolysis reaction Methods 0.000 claims description 6
- 229910021645 metal ion Inorganic materials 0.000 claims description 6
- 150000007524 organic acids Chemical class 0.000 claims description 6
- 238000004537 pulping Methods 0.000 claims description 6
- 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 5
- 239000000203 mixture Substances 0.000 claims description 5
- 230000008569 process Effects 0.000 claims description 5
- 238000003756 stirring Methods 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 4
- GLMOMDXKLRBTDY-UHFFFAOYSA-A [V+5].[V+5].[V+5].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O Chemical compound [V+5].[V+5].[V+5].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O GLMOMDXKLRBTDY-UHFFFAOYSA-A 0.000 claims description 4
- CXKCTMHTOKXKQT-UHFFFAOYSA-N cadmium oxide Inorganic materials [Cd]=O CXKCTMHTOKXKQT-UHFFFAOYSA-N 0.000 claims description 4
- CFEAAQFZALKQPA-UHFFFAOYSA-N cadmium(2+);oxygen(2-) Chemical compound [O-2].[Cd+2] CFEAAQFZALKQPA-UHFFFAOYSA-N 0.000 claims description 4
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 4
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical group [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 4
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 4
- 229910001386 lithium phosphate Inorganic materials 0.000 claims description 4
- SNKMVYBWZDHJHE-UHFFFAOYSA-M lithium;dihydrogen phosphate Chemical compound [Li+].OP(O)([O-])=O SNKMVYBWZDHJHE-UHFFFAOYSA-M 0.000 claims description 4
- XNHGKSMNCCTMFO-UHFFFAOYSA-D niobium(5+);oxalate Chemical compound [Nb+5].[Nb+5].[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O.[O-]C(=O)C([O-])=O XNHGKSMNCCTMFO-UHFFFAOYSA-D 0.000 claims description 4
- 235000006408 oxalic acid Nutrition 0.000 claims description 4
- 230000001681 protective effect Effects 0.000 claims description 4
- ROUPZXDBSPQFLE-UHFFFAOYSA-N triazanium;phosphate;hydrate Chemical compound [NH4+].[NH4+].[NH4+].O.[O-]P([O-])([O-])=O ROUPZXDBSPQFLE-UHFFFAOYSA-N 0.000 claims description 4
- TWQULNDIKKJZPH-UHFFFAOYSA-K trilithium;phosphate Chemical compound [Li+].[Li+].[Li+].[O-]P([O-])([O-])=O TWQULNDIKKJZPH-UHFFFAOYSA-K 0.000 claims description 4
- 239000012002 vanadium phosphate Substances 0.000 claims description 4
- 229910021389 graphene Inorganic materials 0.000 claims description 3
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 claims description 3
- 229920005989 resin Polymers 0.000 claims description 3
- 239000011347 resin Substances 0.000 claims description 3
- 239000002202 Polyethylene glycol Substances 0.000 claims description 2
- 239000004743 Polypropylene Substances 0.000 claims description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 2
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 claims description 2
- 229910052786 argon Inorganic materials 0.000 claims description 2
- 239000002041 carbon nanotube Substances 0.000 claims description 2
- 229910021393 carbon nanotube Inorganic materials 0.000 claims description 2
- 230000009615 deamination Effects 0.000 claims description 2
- 238000006481 deamination reaction Methods 0.000 claims description 2
- 238000007865 diluting Methods 0.000 claims description 2
- 229920001223 polyethylene glycol Polymers 0.000 claims description 2
- 229920001155 polypropylene Polymers 0.000 claims description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 2
- 238000004321 preservation Methods 0.000 claims description 2
- 238000007873 sieving Methods 0.000 claims description 2
- 229920002554 vinyl polymer Polymers 0.000 claims description 2
- 239000004005 microsphere Substances 0.000 claims 1
- 239000011248 coating agent Substances 0.000 abstract description 14
- 238000000576 coating method Methods 0.000 abstract description 11
- 239000000243 solution Substances 0.000 description 31
- 230000001276 controlling effect Effects 0.000 description 20
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 16
- 239000000047 product Substances 0.000 description 15
- 239000005955 Ferric phosphate Substances 0.000 description 14
- 229940032958 ferric phosphate Drugs 0.000 description 14
- 239000007788 liquid Substances 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 8
- 239000012071 phase Substances 0.000 description 8
- 229910052698 phosphorus Inorganic materials 0.000 description 8
- 235000010215 titanium dioxide Nutrition 0.000 description 8
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 7
- MNNHAPBLZZVQHP-UHFFFAOYSA-N diammonium hydrogen phosphate Chemical compound [NH4+].[NH4+].OP([O-])([O-])=O MNNHAPBLZZVQHP-UHFFFAOYSA-N 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 239000011574 phosphorus Substances 0.000 description 7
- 229910000388 diammonium phosphate Inorganic materials 0.000 description 4
- 235000019838 diammonium phosphate Nutrition 0.000 description 4
- 238000010790 dilution Methods 0.000 description 4
- 239000012895 dilution Substances 0.000 description 4
- 238000011065 in-situ storage Methods 0.000 description 4
- 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 4
- 238000012545 processing Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 3
- 239000004254 Ammonium phosphate Substances 0.000 description 3
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 3
- 229910000148 ammonium phosphate Inorganic materials 0.000 description 3
- 235000019289 ammonium phosphates Nutrition 0.000 description 3
- 238000000498 ball milling Methods 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 235000003891 ferrous sulphate Nutrition 0.000 description 3
- 239000011790 ferrous sulphate Substances 0.000 description 3
- 238000005469 granulation Methods 0.000 description 3
- 230000003179 granulation Effects 0.000 description 3
- 229910000359 iron(II) sulfate Inorganic materials 0.000 description 3
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 229940116007 ferrous phosphate Drugs 0.000 description 2
- 230000002431 foraging effect Effects 0.000 description 2
- 229910000155 iron(II) phosphate Inorganic materials 0.000 description 2
- SDEKDNPYZOERBP-UHFFFAOYSA-H iron(ii) phosphate Chemical compound [Fe+2].[Fe+2].[Fe+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O SDEKDNPYZOERBP-UHFFFAOYSA-H 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000003472 neutralizing effect Effects 0.000 description 2
- 239000012716 precipitator Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 1
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 description 1
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000000536 complexating effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001640 fractional crystallisation Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- RQKNQWUJROKKEQ-UHFFFAOYSA-K iron(3+);phosphate;hydrate Chemical compound [OH-].[Fe+3].OP([O-])([O-])=O RQKNQWUJROKKEQ-UHFFFAOYSA-K 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 235000019837 monoammonium phosphate Nutrition 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- DPTATFGPDCLUTF-UHFFFAOYSA-N phosphanylidyneiron Chemical compound [Fe]#P DPTATFGPDCLUTF-UHFFFAOYSA-N 0.000 description 1
- 229910001414 potassium ion Inorganic materials 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004064 recycling Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 239000001488 sodium phosphate Substances 0.000 description 1
- 229910000162 sodium phosphate Inorganic materials 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- RYFMWSXOAZQYPI-UHFFFAOYSA-K trisodium phosphate Chemical compound [Na+].[Na+].[Na+].[O-]P([O-])([O-])=O RYFMWSXOAZQYPI-UHFFFAOYSA-K 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 description 1
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-
- 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
- C01B25/37—Phosphates of heavy metals
- C01B25/375—Phosphates of heavy metals of iron
-
- 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
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/30—Particle morphology extending in three dimensions
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- 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
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- 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
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/11—Powder tap density
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Fertilizers (AREA)
Abstract
The invention discloses a preparation method of anhydrous iron phosphate and a preparation method of a lithium iron phosphate carbon composite material. In addition, a two-step aging mode or a multi-step aging mode is controlled, the dehydration temperature and time are adjusted, primary iron phosphate particles can be controlled at a small level of about 100nm, and a normal Fe/P ratio is obtained. The lithium iron phosphate carbon composite material prepared from the anhydrous iron phosphate is subjected to composite carbon source composite carbon coating by a rheological phase method, so that the sintering temperature can be reduced, the sanding and sintering time can be shortened, the coating uniformity can be improved, and the electrical property, especially the rate capability, of the lithium iron phosphate can be enhanced.
Description
Technical Field
The invention belongs to the field of new energy battery materials, relates to preparation of iron phosphate and lithium iron phosphate carbon composite materials, and particularly relates to a preparation method of anhydrous iron phosphate and a preparation method of lithium iron phosphate carbon composite materials, wherein the preparation method of anhydrous iron phosphate is capable of reducing cost and improving power characteristics of the materials.
Background
Ferric phosphate, also known as ferric phosphate ferric iron and ferric orthophosphate, has a molecular formula of FePO4, and is white and off-white monoclinic crystal powder. Is salt formed by the action of ferric salt solution and sodium phosphate, wherein the iron is in positive trivalent. The method is mainly used for manufacturing lithium iron phosphate battery materials, catalysts, ceramics and the like.
The color of the high-purity ferric phosphate dihydrate is near white or light (pale) yellowish white powder, the color gradually turns yellow along with the loss of crystal water, and the pure anhydrous substance is yellowish white powder. When the phosphorus (P) in the dihydrate ferric phosphate exceeds the standard, the dihydrate ferric phosphate is in grey white or dark grey white; if the iron exceeds the standard, the color is dark yellow. The phosphorus-iron ratio is the most key index for measuring the quality of the iron phosphate and is also the most key factor for determining the quality of the lithium iron phosphate. If a large amount of ferrous iron, sodium ions, potassium ions, sulfate ions and ammonium ions exist in the iron phosphate, the ferric phosphate dihydrate is dark black or grey. Tap density: 1.13-1.59 g/cm3, and the loose packed density is 0.75-0.97 g/cm 3. It is easily dissolved in hydrochloric acid while heating, but is hardly dissolved in other acids, and is hardly dissolved in water, acetic acid, and alcohol.
The existing ferric phosphate is prepared by processing ferrous sulfate heptahydrate, or purifying ferrous phosphate which is a titanium white byproduct, adding ammonia water, DAP (diammonium hydrogen phosphate) and MAP (ammonium dihydrogen phosphate) as a precipitator and a phosphorus source, and performing crystallization control by adopting a one-step aging method. But the relative cost is slightly high, and meanwhile, the oxidation precipitation is insufficient in a one-step heating and aging mode, so that the obtained ferric phosphate has the conditions of larger primary particles and smaller BET; is not beneficial to the subsequent lithium iron phosphate manufacturing and processing, and is difficult to perform the subsequent lithium iron phosphate processing.
The conventional high-power lithium iron phosphate can be coated with an organic carbon source and an inorganic carbon source by solid-phase synthesis and a carbothermic reduction method, so that the power performance of the product is improved by reducing primary particles in sanding.
In the synthesis of the lithium iron phosphate, the carbon coating is not uniform enough sometimes, and the repeated grinding and high-temperature long-time sintering are needed, so that the time consumption is long, and the sintering temperature is as high as 700-.
In Chinese patent CN 111333047A, the preparation is carried out by oxidation precipitation method, phosphoric acid and oxidation reagent are added for many times, and iron phosphate with higher purity is obtained by one-time aging. However, the boundaries of the primary particles are unclear when viewed from the product particles, and the overall primary particles are large, which is not beneficial to subsequent lithium iron phosphate processing.
Chinese patent CN101244813A describes a preparation method of basic lithium iron phosphate, two iron sources are adopted, the tap density of the obtained product is 1.3-1.6g/mL, the particle size is 10-20um, and the size of the primary particle of the iron phosphate is not mentioned.
Disclosure of Invention
In order to solve the problems, the invention aims to disclose a preparation method of anhydrous iron phosphate with reduced cost, the invention adopts a green vanadium product purified from titanium dioxide to synthesize an iron phosphate product, the raw material is purified by using a titanium dioxide byproduct, and N, P-containing fertilizers such as APP or urea are used for replacing DAP or MAP and simultaneously used for regulating and controlling PH. On one hand, the cost can be reduced to a certain degree, and meanwhile, the pollution can be reduced. In addition, the two-step or multi-step aging mode of the aging mode is controlled, the dehydration temperature and time are adjusted, the primary iron phosphate particles can be controlled at a smaller level of about 100nm, and a normal Fe/P ratio is obtained.
The invention also discloses a preparation method of the lithium iron phosphate carbon composite material for improving the power characteristic of the material, wherein the lithium iron phosphate carbon composite material is prepared by adopting the anhydrous iron phosphate, and composite carbon source composite carbon coating is carried out by a rheological phase method, so that the sintering temperature can be reduced, the sanding and sintering time can be shortened, the coating uniformity can be improved, and the electrical property, especially the rate capability, of the lithium iron phosphate can be enhanced.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a preparation method of anhydrous iron phosphate, which comprises the following steps:
1) dissolving titanium dioxide byproducts, diluting, removing impurities, and filtering to obtain a solution with the iron ion mass fraction of 3% -5%;
2) taking 1mol of iron ions as a reference, adding the nitrogen-phosphorus binary compound fertilizer into deionized water containing phosphoric acid for hydrolysis, and performing PO4 3-Adding phosphoric acid and hydrogen peroxide with the content of 1-1.5mol/L, cooling, and adding ammonia water to obtain a phosphate solution;
3) putting the solution containing iron ions obtained in the step 1) into an aging kettle, and dropwise adding the phosphate solution obtained in the step 2) within 1h, wherein the pH value of the phosphate solution is controlled to be less than 7; controlling the pH value of the dripping end point to be less than 3, carrying out heat preservation for 45-60 minutes, carrying out first-stage filter pressing washing after oxidation and precipitation, recovering filtrate, and using filter cakes for later use;
4) adding phosphoric acid and deionized water into the filter cake obtained in the step 3) for pulping, and aging at least once; performing secondary filter pressing and drying on the aged slurry to obtain basic ammonium phosphate hydrate;
5) and (3) dehydrating and deaminating the basic ammonium phosphate hydrate obtained in the step (4) by using a muffle furnace or a tubular furnace, and drying and dehydrating to obtain anhydrous iron phosphate.
According to the iron phosphate synthesis scheme, a titanium dioxide byproduct ferrous sulfate is dissolved in deionized water for dilution, then an impurity removing agent and a complexing precipitator are added in sequence, and a purified ferrous solution is obtained after multiple filtration.
The method is different from the method for preparing the ferrous phosphate by the liquid-phase method of preparing the lithium iron phosphate in the Chinese patent CN 113526480A, a multi-step neutralizing agent adding and impurity removing mode is needed, the neutralizing agent adding and impurity removing mode is not needed, the solution is prepared into the phosphate solution, and the phosphate solution is directly washed and filtered after the oxidizing and precipitating reaction with the ferrous sulfate.
The phosphate solution of the invention is prepared by dissolving APP (nitrogen-phosphorus binary compound fertilizer) in deionized water containing phosphoric acid preferentially for hydrolysis, and adjusting the pH of the deionized water to be 0.9-2.0, so that the APP can be hydrolyzed sufficiently and quickly to obtain PO4 3-，NH4 +And PO4 3-Will subsequently participate in providing a source of phosphorus and a source of nitrogen. Then, adding phosphoric acid, hydrogen peroxide and ammonia water into the dissolved APP solution respectively to prepare a phosphate solution. Firstly, ferrous sulfate mother liquor is put into an aging kettle, and prepared phosphate solution is slowly dripped to carry out oxidation precipitation for a certain time. And then, washing, pulping and aging again, wherein the aging mode is aging in two steps or multiple steps, washing again, filtering, drying and dehydrating to obtain the required anhydrous iron phosphate product. The ferric phosphate is not a conventional pure ferric phosphate product, but a basic ferric ammonium phosphate product, and the molecular formula of the basic ferric ammonium phosphate product is NH4Fe2(PO4)2OH·nH2O, the primary particles of the finished product are about dozens to one hundred nanometers, and the BET can be controlled to be 7-20m2/g，FeThe ratio of/P can reach 0.96-0.98.
The anhydrous ferric phosphate is obtained after the basic ferric ammonium phosphate is dried, dehydrated and deaminated, has small primary particles, belongs to nano-scale ferric phosphate, and has the tap density of 0.7-1.0g/mL and the particle size of 1-18 mu m. And meanwhile, the iron phosphate is loose and porous, so that the iron phosphate can be conveniently processed during subsequent iron phosphate preparation.
As a preferred embodiment of the present invention, in step 2), NH is added3 isThe amount of substance is 1-2mol, H2O2The amount of (b) is 0.3 to 1 mol.
As a preferable scheme of the invention, in the step 3), the pH value of the recovered filtrate is 7.5-9, and the conductivity is less than or equal to 13 ms/cm.
As a preferable scheme of the invention, in the step 4), the aging temperature is 75-95 ℃, the drying temperature is 80-200 ℃, and the drying mode comprises flash drying, microwave drying or double-cone drying.
As a preferable scheme of the invention, in the step 5), the temperature of the dehydration deamination is 350-600 ℃, and the time is 4-6 h.
In a preferable embodiment of the present invention, the anhydrous iron phosphate has a tap density of 0.7 to 1.0g/mL and a particle diameter of 1 to 18 μm.
The second aspect of the invention provides a preparation method of a lithium iron phosphate carbon composite material, which comprises the following steps:
a) adding the anhydrous iron phosphate, the lithium source, sucrose or glucose, the organic acid and the metal ion additive obtained by the method into deionized water for dispersing, and sequentially carrying out coarse grinding and fine grinding to obtain powder;
b) adding a carbon source with the mass fraction of 5% -10% of lithium iron phosphate into an ethanol solution for dissolving, adding the powder obtained in the step a), and stirring and dispersing; spray drying and granulating to obtain microspherical precursor;
c) sintering the precursor obtained in the step b) in the protective gas atmosphere, cooling to room temperature, crushing, and sieving to obtain the microspherical lithium iron phosphate carbon composite material.
As a preferable scheme of the invention, in the step a), the ratio of the nano iron phosphate, the lithium source, the sucrose or the glucose, the organic acid and the metal ion additive is 1:1:0.08-0.3: 0.02-0.1: 0.01-0.1, the lithium source is lithium carbonate, lithium phosphate, lithium dihydrogen phosphate or a combination of a plurality of lithium sources, the organic acid is oxalic acid or citric acid, and the metal ion additive comprises vanadium pentoxide, vanadium phosphate, cadmium oxide or niobium oxalate.
As a preferable embodiment of the present invention, in step b), the carbon source is polyvinyl butyral, polyvinyl formal acetaldehyde, polypropylene, polyvinyl alcohol, polyethylene glycol, PEGA resin, carbon nanotubes, graphene flakes, or a mixture of two or more groups; in the spray drying process, the flow rate of the airflow is 180-220mL/h, the inlet temperature is 185-225 ℃, and the outlet temperature is 85-95 ℃.
As a preferable scheme of the invention, in the step c), the atmosphere of the protective gas is nitrogen or argon, the sintering temperature is 550-700 ℃, and the primary particles of the microspherical lithium iron phosphate carbon composite material are 100-200 nm.
Compared with the prior art, the invention has the following beneficial effects:
1) according to the anhydrous iron phosphate, a small amount of phosphoric acid, DAP and MAP are replaced by a low amount of nitrogen and phosphorus fertilizer, so that the cost is low, the crystallization degree is optimized in a fractional crystallization mode, grains grow uniformly, the fusion of particle boundaries is not easy to occur, and the phosphate dripping mode is simplified;
2) the carbon source composite coating mode of the lithium iron phosphate carbon composite material is to carry out in-situ coating by a rheological phase method, has better and more uniform glucose coating effect compared with the method of simply using sucrose, and simultaneously reduces the sanding time to obtain the lithium iron phosphate carbon composite material with higher multiplying power;
3) the method of the invention can reduce the cost and improve the power characteristic of the material to a certain extent.
Drawings
Fig. 1 is an SEM image of anhydrous iron phosphate prepared according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Example 1
The embodiment provides a preparation method of anhydrous iron phosphate, which comprises the following steps:
1) at normal temperature, dissolving the titanium dioxide byproduct in deionized water for dilution, removing impurities, filtering, removing filter cakes, leaving clear liquid, and preparing iron ions with the concentration of 3%;
2) preparing phosphate dropping liquid: taking 1mol of iron as a reference, preferably dissolving APP (nitrogen-phosphorus binary compound fertilizer) in deionized water containing phosphoric acid for hydrolysis, and controlling the water temperature at 30 ℃, wherein the ratio of APP to phosphoric acid is: the proportion of the deionized water is controlled within 4:1:50, PO43-:1mol；
3) On the basis of the step 2, adding phosphoric acid and hydrogen peroxide again, cooling, and then adding ammonia water and NH3The mole number is 1mol, H2O2The number of moles of (B) is 0.3 mol. NH (NH)4 +And PO4 3-The ratio of (A) to (B) is controlled to be 2.05: within 1, while the pH of the phosphate solution is controlled to be<7, gradually dripping phosphate solution into the iron ion-containing solution obtained in the step 1), controlling the dripping time within 1h, and controlling the dripping end point ph<3, then keeping the temperature for 45 minutes; carrying out primary filter pressing washing after the oxidation precipitation, wherein the washed filtrate can be recycled; testing the pH value of the filtrate to be 7.5-9, and the conductivity to be less than or equal to 13 ms/cm;
4) after washing, carrying out filter pressing, adding phosphoric acid and water into a filter cake after filter pressing, pulping, controlling the amount of prepared phosphorus to be 0.08eq, heating by 1/4 amounts, controlling the temperature to be 75 ℃, preferentially aging, observing whiteness change, keeping the temperature for a certain time, then pumping the residual slurry into an aging kettle once or for multiple times, heating to 75 ℃ and aging; drying the aged slurry through secondary filter pressing, wherein the drying temperature is as follows: flash evaporation is adopted in a drying mode at 80 ℃ to obtain basic hydrated ammonium ferric phosphate, the primary particles of the finished product are about dozens to one hundred nanometers, and the BET can be controlled at 7-20m2The Fe/P ratio can reach 0.96-0.98;
5) and (3) dehydrating and deaminating by using a muffle furnace or a tube furnace, controlling the temperature at 350 ℃ and the time at 4h, and drying and dehydrating to obtain the anhydrous iron phosphate.
The SEM image of the anhydrous iron phosphate prepared is shown in FIG. 1.
Example 2
The embodiment provides a preparation method of anhydrous iron phosphate, which comprises the following steps:
1) at normal temperature, dissolving the titanium dioxide byproduct in deionized water for dilution, removing impurities, filtering, removing filter cakes, leaving clear liquid, and preparing iron ions with the concentration of 4%;
2) preparing phosphate dropping liquid: taking 1mol of iron as a reference, preferentially dissolving APP (nitrogen-phosphorus binary compound fertilizer) in phosphoric acid-containing deionized water for hydrolysis, and controlling the water temperature at 35 ℃, wherein the ratio of APP to phosphoric acid is: the proportion of the deionized water is controlled within 4:1:50, PO43-:1.2mol；
3) On the basis of the step 2, adding phosphoric acid and hydrogen peroxide again, cooling, and then adding ammonia water and NH3The mole number is 1.5mol, H2O2In a molar amount of 0.5mol, NH4 +And PO4 3-The ratio of (A) to (B) is controlled to be 2.05: within 1, while the pH of the phosphate solution is controlled to be<7, gradually dripping phosphate solution into the iron ion-containing solution obtained in the step 1), controlling the dripping time within 1h, and controlling the dripping end point ph<And 3, preserving the heat for 50 minutes, performing primary filter pressing washing after oxidation and precipitation, and recovering and treating the washed filtrate. Testing the pH value of the filtrate to be 7.5-9, and the conductivity to be less than or equal to 13 ms/cm;
4) firstly, carrying out filter pressing after washing, adding phosphoric acid and water into a filter cake after filter pressing for pulping, controlling the amount of prepared phosphorus to be 0.06eq, heating up by 1/3 amounts, controlling the temperature to be 85 ℃ for preferential aging, observing whiteness change, keeping the temperature for a certain time, then pumping the residual slurry into an aging kettle for one or more times, heating up to 85 ℃ for aging, carrying out secondary filter pressing drying on the aged slurry, and drying at the temperature: microwave drying at 120 deg.C to obtain basic ammonium ferric phosphate hydrate with primary particle size of tens to one hundredAbout nanometer, BET can be controlled at 7-20m2The Fe/P ratio can reach 0.96-0.98;
5) and (3) dehydrating and deaminating by using a muffle furnace or a tube furnace, controlling the temperature at 400 ℃ and the time at 5h, and drying and dehydrating to obtain the anhydrous iron phosphate.
Example 3
The embodiment provides a preparation method of anhydrous iron phosphate, which comprises the following steps:
1) at normal temperature, dissolving the titanium dioxide byproduct in deionized water for dilution, removing impurities, filtering, removing filter cakes, leaving clear liquid, and preparing iron ions with the concentration of 5%;
2) preparing phosphate dropping liquid: taking 1mol of iron as a reference, preferentially dissolving APP (nitrogen-phosphorus binary compound fertilizer) in phosphoric acid-containing deionized water for hydrolysis, and controlling the water temperature at 40 ℃, wherein the ratio of APP to phosphoric acid: the proportion of the deionized water is controlled within 4:1:50, PO43-:1.5mol；
3) On the basis of the step 2, adding phosphoric acid and hydrogen peroxide again, cooling, and adding ammonia water and NH3The mole number is 2mol, H2O2The number of moles of (b) is 1 mol. NH4 +And PO4 3-The ratio of (A) to (B) is controlled to be 2.05: within 1, while the pH of the phosphate solution is controlled<7, gradually dripping phosphate solution into the iron ion-containing solution obtained in the step 1), controlling the dripping time within 1h, and controlling the dripping end point ph<3, then preserving the heat for 60 minutes, carrying out first-stage filter pressing washing after oxidation and precipitation, and recycling the washed filtrate, wherein the pH of the tested filtrate is 7.5-9, and the conductivity is less than or equal to 13 ms/cm;
4) firstly, carrying out filter pressing after washing, adding phosphoric acid and water into a filter cake after filter pressing for pulping, controlling the amount of phosphorus prepared at 0.02eq, heating up by 1/2 amounts, controlling the temperature at 95 ℃ for preferential aging, observing whiteness change, keeping the temperature for a certain time, then pumping the residual slurry into an aging kettle for one or more times, heating up to 95 ℃ for aging, carrying out secondary filter pressing drying on the aged slurry, and drying at the temperature: the basic hydrated ammonium ferric phosphate is obtained by adopting double-cone drying at 200 ℃, the primary particles of the finished product are about dozens to one hundred nanometers, and the BET can be controlled at 7-20m2The Fe/P ratio can reach 0.96-0.98;
5) and (3) dehydrating and deaminating by using a muffle furnace or a tube furnace, controlling the temperature at 600 ℃ and the time at 6h, and drying and dehydrating to obtain the anhydrous iron phosphate.
Example 4
The embodiment provides a preparation method of a lithium iron phosphate carbon composite material, which comprises the following steps:
a) the anhydrous iron phosphate, lithium carbonate, sucrose, citric acid and cadmium oxide prepared in the embodiment 1 are mixed according to a certain mass ratio, and the weight ratio of the anhydrous iron phosphate is as follows: lithium carbonate: cadmium oxide: sucrose: citric acid 1: 0.08: 0.02: 0.01, adding deionized water for dispersing, and then carrying out coarse grinding and fine grinding and sanding for 3 hours;
b) adding polyvinyl butyral with the mass fraction of 5% of lithium iron phosphate into an ethanol solution for dissolving, then adding the dissolved solution into the powder after ball milling, and stirring and dispersing for 5 hours; the obtained solid-liquid rheological phase mixture is subjected to spray drying to obtain a microspherical precursor under a physical and chemical granulation process at the inlet temperature of 200 ℃ and the outlet temperature of 90 ℃ under the flow rate of 200mL/h of airflow;
c) and sintering the dried sample under the protection of nitrogen, wherein the sintering temperature is 550 ℃, at the temperature, a decomposed coating agent carbon source can be subjected to in-situ coating on the surface of the synthesized lithium iron phosphate in a rheological phase mode, and then the sample is crushed and sieved after being cooled to room temperature, so that the composite material similar to microspherical lithium iron phosphate carbon is obtained, and the primary particles of the finished product are controlled to be about 100-200 nm.
Example 5
The embodiment provides a preparation method of a lithium iron phosphate carbon composite material, which comprises the following steps:
a) the anhydrous iron phosphate, lithium dihydrogen phosphate, glucose, oxalic acid and vanadium phosphate prepared in the embodiment 2 are mixed according to a certain mass ratio, and the anhydrous iron phosphate: lithium dihydrogen phosphate: vanadium phosphate: glucose: oxalic acid 1: 0.1: 0.05: 0.08, adding deionized water for dispersing, and then carrying out coarse grinding and fine grinding, and sanding for 4 hours;
b) adding other carbon source PEGA resin with the mass fraction of 8 percent of lithium iron phosphate into ethanol solution for dissolving, then adding the dissolved solution into the powder after ball milling, stirring and dispersing for 4 hours to obtain a solid-liquid rheological phase mixture, and obtaining a microspherical precursor by a spray drying method under the physical and chemical granulation process that the inlet temperature is 185 ℃ and the outlet temperature is 85 ℃ under the flow rate of 200mL/h of airflow;
c) and sintering the dried sample under Ar protection, wherein the sintering temperature is 600 ℃, at the temperature, the decomposed coating agent carbon source can be subjected to in-situ coating on the surface of the synthesized lithium iron phosphate in a rheological phase mode, and then the sample is crushed and sieved after being cooled to room temperature, so that the composite material similar to microspherical lithium iron phosphate carbon is obtained, and the primary particles of the finished product are controlled to be about 100-200 nm.
Example 6
The embodiment provides a preparation method of a lithium iron phosphate carbon composite material, which comprises the following steps:
a) the anhydrous iron phosphate, lithium phosphate, glucose, citric acid and niobium oxalate prepared in the embodiment 3 are proportioned according to a certain mass ratio, and the anhydrous iron phosphate: lithium phosphate: niobium oxalate: glucose: 1: 0.3: 0.1: 0.1, adding deionized water for dispersing, and then carrying out coarse grinding and fine grinding, and sanding for 5 hours;
b) adding flake graphene with the mass fraction of 10% of lithium iron phosphate into an ethanol solution for dissolving, then adding the dissolved solution into powder subjected to ball milling, stirring and dispersing for 5 hours to obtain a solid-liquid rheological phase mixture, and obtaining a microspherical precursor by a spray drying method under a physicochemical granulation process that the airflow is 200mL/h, the inlet temperature is 220 ℃ and the outlet temperature is about 95 ℃.
c) And sintering the dried sample under the protection of nitrogen or Ar, wherein the sintering temperature is 650 ℃. At the temperature, the decomposed carbon source of the coating agent can carry out in-situ coating on the surface of the synthesized lithium iron phosphate in a rheological phase mode, and then the sample is crushed and sieved after being cooled to room temperature, so as to obtain the composite material similar to microspherical lithium iron phosphate carbon, wherein the primary particle of the finished product is controlled to be about 100-200 nm.
The microspherical lithium iron phosphate carbon-like composite material obtained in example 4 was assembled into a swagelok die battery for testing, and electrical properties were tested by using lithium metal as the negative electrode and commercial lithium iron phosphate electrolyte as the electrolyte. Conventionally, a material coated only with glucose/sucrose carbon is adopted, wherein the 0.1C capacity of the material is 152-160mAh/g, and the 5C capacity retention rate is about 80-85%; the 0.1C capacity of the lithium iron phosphate can reach 154-160mAh/g, and the 5C capacity retention rate is about 88-92% higher than that of LFP prepared by a conventional method.
While the invention has been described with respect to a preferred embodiment, it will be understood by those skilled in the art that the foregoing and other changes, omissions and deviations in the form and detail thereof may be made without departing from the scope of this invention. Those skilled in the art can make various changes, modifications and equivalent arrangements, which are equivalent to the embodiments of the present invention, without departing from the spirit and scope of the present invention, and which may be made by utilizing the techniques disclosed above; meanwhile, any equivalent changes, modifications and evolutions of the above embodiments according to the essential technology of the present invention are still within the scope of the technical solution of the present invention.
Claims (10)
1. The preparation method of the anhydrous iron phosphate is characterized by comprising the following steps:
1) dissolving titanium dioxide byproducts, diluting, removing impurities, and filtering to obtain a solution with the iron ion mass fraction of 3% -5%;
2) taking 1mol of iron ions as a reference, adding the nitrogen-phosphorus binary compound fertilizer into deionized water containing phosphoric acid for hydrolysis, and performing PO4 3-Adding phosphoric acid and hydrogen peroxide with the content of 1-1.5mol/L, cooling, and adding ammonia water to obtain a phosphate solution;
3) putting the solution containing iron ions obtained in the step 1) into an aging kettle, and dropwise adding the phosphate solution obtained in the step 2) within 1h, wherein the pH value of the phosphate solution is controlled to be less than 7; controlling the pH value of the dripping end point to be less than 3, carrying out heat preservation for 45-60 minutes, carrying out first-stage filter pressing washing after oxidation and precipitation, recovering filtrate, and using filter cakes for later use;
4) adding phosphoric acid and deionized water into the filter cake obtained in the step 3) for pulping, and aging at least once; the aged slurry is subjected to secondary filter pressing and drying to obtain basic ammonium phosphate hydrate;
5) and (3) dehydrating and deaminating the basic ammonium phosphate hydrate obtained in the step (4) by using a muffle furnace or a tubular furnace, and drying and dehydrating to obtain anhydrous iron phosphate.
2. The method for preparing anhydrous iron phosphate according to claim 1, wherein in step 2), NH is added3 isThe amount of substance is 1-2mol, H2O2The amount of (b) is 0.3 to 1 mol.
3. The method for preparing anhydrous iron phosphate according to claim 1, wherein in the step 3), the recovered filtrate has a pH of 7.5-9 and a conductivity of 13ms/cm or less.
4. The method for preparing anhydrous iron phosphate according to claim 1, wherein in the step 4), the aging temperature is 75-95 ℃, the drying temperature is 80-200 ℃, and the drying mode comprises flash drying, microwave drying or double-cone drying.
5. The method for preparing anhydrous iron phosphate according to claim 1, wherein in the step 5), the temperature of the dehydration deamination is 350-600 ℃ and the time is 4-6 h.
6. The method for producing anhydrous iron phosphate according to claim 1, wherein the anhydrous iron phosphate has a tap density of 0.7 to 1.0g/mL and a particle size of 1 to 18 μm.
7. The preparation method of the lithium iron phosphate carbon composite material is characterized by comprising the following steps:
a) dispersing the anhydrous iron phosphate prepared according to any one of claims 1 to 6, a lithium source, sucrose or glucose, an organic acid and a metal ion additive in deionized water, and sequentially performing coarse grinding and fine grinding to obtain a powder;
b) adding a carbon source with the mass fraction of 5% -10% of lithium iron phosphate into an ethanol solution for dissolving, adding the powder obtained in the step a), and stirring and dispersing; spray drying and granulating to obtain microspheric precursor;
c) sintering the precursor obtained in the step b) in the protective gas atmosphere, cooling to room temperature, crushing, and sieving to obtain the microspherical lithium iron phosphate carbon composite material.
8. The method for preparing a lithium iron phosphate carbon composite material according to claim 7, wherein in the step a), the ratio of the nano iron phosphate, the lithium source, sucrose or glucose, the organic acid and the metal ion additive is 1:1:0.08-0.3: 0.02-0.1: 0.01-0.1, the lithium source is lithium carbonate, lithium phosphate, lithium dihydrogen phosphate or a combination of a plurality of lithium sources, the organic acid is oxalic acid or citric acid, and the metal ion additive comprises vanadium pentoxide, vanadium phosphate, cadmium oxide or niobium oxalate.
9. The method for preparing the lithium iron phosphate carbon composite material according to claim 7, wherein in the step b), the carbon source is polyvinyl butyral, polyvinyl formal acetaldehyde, polypropylene, polyvinyl alcohol, polyethylene glycol, PEGA resin, carbon nanotube, graphene sheet or a mixture of two or more groups; in the spray drying process, the flow rate of the airflow is 180-220mL/h, the inlet temperature is 185-225 ℃, and the outlet temperature is 85-95 ℃.
10. The method for preparing the lithium iron phosphate carbon composite material as claimed in claim 7, wherein in the step c), the atmosphere of the protective gas is nitrogen or argon, the sintering temperature is 550-700 ℃, and the primary particles of the microspherical lithium iron phosphate carbon composite material are 100-200 nm.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102556996A (en) * | 2010-12-30 | 2012-07-11 | 中国电子科技集团公司第十八研究所 | Preparation method for high-tap-density lithium iron phosphate |
| CN103569981A (en) * | 2012-08-02 | 2014-02-12 | 浙江新安化工集团股份有限公司 | Method for producing orthophosphate products from polyphosphates through hydrolysis |
| WO2015086301A1 (en) * | 2013-12-13 | 2015-06-18 | Basf Se | Process for producing electrode materials |
| CN105470503A (en) * | 2014-08-08 | 2016-04-06 | 中国电子科技集团公司第十八研究所 | Preparation method of spherical lithium iron phosphate having uniform carbon cladding layer |
| CN110540185A (en) * | 2019-09-17 | 2019-12-06 | 襄阳泽东新能源发展有限公司 | synthesis process of battery-grade iron phosphate |
| CN111115605A (en) * | 2020-01-09 | 2020-05-08 | 乳源东阳光磁性材料有限公司 | Preparation method and production device of anhydrous iron phosphate |
| CN113526480A (en) * | 2021-07-13 | 2021-10-22 | 曲靖市德方纳米科技有限公司 | Method for preparing ferrous phosphate from titanium dioxide byproduct |
-
2022
- 2022-04-26 CN CN202210445065.1A patent/CN114772571A/en active Pending
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102556996A (en) * | 2010-12-30 | 2012-07-11 | 中国电子科技集团公司第十八研究所 | Preparation method for high-tap-density lithium iron phosphate |
| CN103569981A (en) * | 2012-08-02 | 2014-02-12 | 浙江新安化工集团股份有限公司 | Method for producing orthophosphate products from polyphosphates through hydrolysis |
| WO2015086301A1 (en) * | 2013-12-13 | 2015-06-18 | Basf Se | Process for producing electrode materials |
| CN105470503A (en) * | 2014-08-08 | 2016-04-06 | 中国电子科技集团公司第十八研究所 | Preparation method of spherical lithium iron phosphate having uniform carbon cladding layer |
| CN110540185A (en) * | 2019-09-17 | 2019-12-06 | 襄阳泽东新能源发展有限公司 | synthesis process of battery-grade iron phosphate |
| CN111115605A (en) * | 2020-01-09 | 2020-05-08 | 乳源东阳光磁性材料有限公司 | Preparation method and production device of anhydrous iron phosphate |
| CN113526480A (en) * | 2021-07-13 | 2021-10-22 | 曲靖市德方纳米科技有限公司 | Method for preparing ferrous phosphate from titanium dioxide byproduct |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115432687A (en) * | 2022-09-20 | 2022-12-06 | 荆门市格林美新材料有限公司 | Preparation method of lithium iron phosphate material |
| CN115432687B (en) * | 2022-09-20 | 2023-12-15 | 荆门市格林美新材料有限公司 | Preparation method of lithium iron phosphate material |
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