CN117558883A - Lithium iron manganese phosphate composite material and preparation method thereof - Google Patents
Lithium iron manganese phosphate composite material and preparation method thereof Download PDFInfo
- Publication number
- CN117558883A CN117558883A CN202311443555.9A CN202311443555A CN117558883A CN 117558883 A CN117558883 A CN 117558883A CN 202311443555 A CN202311443555 A CN 202311443555A CN 117558883 A CN117558883 A CN 117558883A
- Authority
- CN
- China
- Prior art keywords
- composite material
- lithium
- lithium iron
- manganese phosphate
- phosphate composite
- 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
- 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 title claims abstract description 93
- 239000002131 composite material Substances 0.000 title claims abstract description 73
- 238000002360 preparation method Methods 0.000 title claims abstract description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 123
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 90
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 90
- 150000007524 organic acids Chemical class 0.000 claims abstract description 56
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 claims abstract description 48
- 229910000616 Ferromanganese Inorganic materials 0.000 claims abstract description 46
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 29
- 238000000034 method Methods 0.000 claims abstract description 22
- 238000006243 chemical reaction Methods 0.000 claims abstract description 17
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229910001416 lithium ion Inorganic materials 0.000 claims abstract description 13
- 239000000243 solution Substances 0.000 claims description 55
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 41
- 238000000227 grinding Methods 0.000 claims description 33
- 238000001035 drying Methods 0.000 claims description 32
- 239000011572 manganese Substances 0.000 claims description 32
- 239000000463 material Substances 0.000 claims description 24
- 239000007864 aqueous solution Substances 0.000 claims description 23
- 239000011259 mixed solution Substances 0.000 claims description 21
- QZPSXPBJTPJTSZ-UHFFFAOYSA-N aqua regia Chemical compound Cl.O[N+]([O-])=O QZPSXPBJTPJTSZ-UHFFFAOYSA-N 0.000 claims description 20
- 238000001354 calcination Methods 0.000 claims description 19
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims description 16
- 238000002156 mixing Methods 0.000 claims description 16
- 229910052742 iron Inorganic materials 0.000 claims description 15
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 13
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 12
- 239000002202 Polyethylene glycol Substances 0.000 claims description 12
- 229920001223 polyethylene glycol Polymers 0.000 claims description 12
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 11
- 229910052744 lithium Inorganic materials 0.000 claims description 11
- 229910052748 manganese Inorganic materials 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims description 9
- SNKMVYBWZDHJHE-UHFFFAOYSA-M lithium;dihydrogen phosphate Chemical compound [Li+].OP(O)([O-])=O SNKMVYBWZDHJHE-UHFFFAOYSA-M 0.000 claims description 9
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 8
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 8
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 8
- 238000010438 heat treatment Methods 0.000 claims description 8
- 229910052698 phosphorus Inorganic materials 0.000 claims description 8
- 239000011574 phosphorus Substances 0.000 claims description 8
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 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 6
- 229940062993 ferrous oxalate Drugs 0.000 claims description 6
- 229960001031 glucose Drugs 0.000 claims description 6
- OWZIYWAUNZMLRT-UHFFFAOYSA-L iron(2+);oxalate Chemical compound [Fe+2].[O-]C(=O)C([O-])=O OWZIYWAUNZMLRT-UHFFFAOYSA-L 0.000 claims description 6
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 6
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 6
- RGVLTEMOWXGQOS-UHFFFAOYSA-L manganese(2+);oxalate Chemical compound [Mn+2].[O-]C(=O)C([O-])=O RGVLTEMOWXGQOS-UHFFFAOYSA-L 0.000 claims description 6
- 235000006408 oxalic acid Nutrition 0.000 claims description 5
- 239000011268 mixed slurry Substances 0.000 claims description 4
- 239000000376 reactant Substances 0.000 claims description 4
- 230000035484 reaction time Effects 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
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 claims description 3
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 3
- 229920002125 Sokalan® Polymers 0.000 claims description 3
- 229930006000 Sucrose Natural products 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 3
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 3
- LFVGISIMTYGQHF-UHFFFAOYSA-N ammonium dihydrogen phosphate Chemical compound [NH4+].OP(O)([O-])=O LFVGISIMTYGQHF-UHFFFAOYSA-N 0.000 claims description 3
- 229910000387 ammonium dihydrogen phosphate Inorganic materials 0.000 claims description 3
- 239000002270 dispersing agent Substances 0.000 claims description 3
- 229960002089 ferrous chloride Drugs 0.000 claims description 3
- 235000003891 ferrous sulphate Nutrition 0.000 claims description 3
- 239000011790 ferrous sulphate Substances 0.000 claims description 3
- NMCUIPGRVMDVDB-UHFFFAOYSA-L iron dichloride Chemical compound Cl[Fe]Cl NMCUIPGRVMDVDB-UHFFFAOYSA-L 0.000 claims description 3
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 claims description 3
- 229910000359 iron(II) sulfate Inorganic materials 0.000 claims description 3
- 229910001386 lithium phosphate Inorganic materials 0.000 claims description 3
- 229940071125 manganese acetate Drugs 0.000 claims description 3
- 235000006748 manganese carbonate Nutrition 0.000 claims description 3
- 239000011656 manganese carbonate Substances 0.000 claims description 3
- 229940093474 manganese carbonate Drugs 0.000 claims description 3
- UOGMEBQRZBEZQT-UHFFFAOYSA-L manganese(2+);diacetate Chemical compound [Mn+2].CC([O-])=O.CC([O-])=O UOGMEBQRZBEZQT-UHFFFAOYSA-L 0.000 claims description 3
- 229910000016 manganese(II) carbonate Inorganic materials 0.000 claims description 3
- XMWCXZJXESXBBY-UHFFFAOYSA-L manganese(ii) carbonate Chemical compound [Mn+2].[O-]C([O-])=O XMWCXZJXESXBBY-UHFFFAOYSA-L 0.000 claims description 3
- 235000019837 monoammonium phosphate Nutrition 0.000 claims description 3
- 239000004584 polyacrylic acid Substances 0.000 claims description 3
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 3
- 239000005720 sucrose Substances 0.000 claims description 3
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-JCYAYHJZSA-N Dextrotartaric acid Chemical compound OC(=O)[C@H](O)[C@@H](O)C(O)=O FEWJPZIEWOKRBE-JCYAYHJZSA-N 0.000 claims description 2
- 229930091371 Fructose Natural products 0.000 claims description 2
- 239000005715 Fructose Substances 0.000 claims description 2
- RFSUNEUAIZKAJO-ARQDHWQXSA-N Fructose Chemical compound OC[C@H]1O[C@](O)(CO)[C@@H](O)[C@@H]1O RFSUNEUAIZKAJO-ARQDHWQXSA-N 0.000 claims description 2
- FEWJPZIEWOKRBE-UHFFFAOYSA-N Tartaric acid Natural products [H+].[H+].[O-]C(=O)C(O)C(O)C([O-])=O FEWJPZIEWOKRBE-UHFFFAOYSA-N 0.000 claims description 2
- 235000015165 citric acid Nutrition 0.000 claims description 2
- 229960001781 ferrous sulfate Drugs 0.000 claims description 2
- 239000011261 inert gas Substances 0.000 claims description 2
- 229940099596 manganese sulfate Drugs 0.000 claims description 2
- 235000007079 manganese sulphate Nutrition 0.000 claims description 2
- 239000011702 manganese sulphate Substances 0.000 claims description 2
- MIVBAHRSNUNMPP-UHFFFAOYSA-N manganese(2+);dinitrate Chemical compound [Mn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O MIVBAHRSNUNMPP-UHFFFAOYSA-N 0.000 claims description 2
- SQQMAOCOWKFBNP-UHFFFAOYSA-L manganese(II) sulfate Chemical compound [Mn+2].[O-]S([O-])(=O)=O SQQMAOCOWKFBNP-UHFFFAOYSA-L 0.000 claims description 2
- 230000004048 modification Effects 0.000 claims description 2
- 238000012986 modification Methods 0.000 claims description 2
- 239000006012 monoammonium phosphate Substances 0.000 claims description 2
- 239000005011 phenolic resin Substances 0.000 claims description 2
- 229920001568 phenolic resin Polymers 0.000 claims description 2
- 230000001105 regulatory effect Effects 0.000 claims description 2
- 239000011975 tartaric acid Substances 0.000 claims description 2
- 235000002906 tartaric acid Nutrition 0.000 claims description 2
- 238000004519 manufacturing process Methods 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 19
- 230000001976 improved effect Effects 0.000 abstract description 14
- 239000002243 precursor Substances 0.000 abstract description 12
- 150000002500 ions Chemical class 0.000 abstract description 9
- 238000000975 co-precipitation Methods 0.000 abstract description 7
- 238000005056 compaction Methods 0.000 abstract description 7
- 238000003837 high-temperature calcination Methods 0.000 abstract description 7
- 230000008569 process Effects 0.000 abstract description 7
- 230000005540 biological transmission Effects 0.000 abstract description 6
- 239000007774 positive electrode material Substances 0.000 abstract description 4
- 230000002194 synthesizing effect Effects 0.000 abstract description 2
- 239000002244 precipitate Substances 0.000 description 28
- 239000000843 powder Substances 0.000 description 19
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 13
- 239000000203 mixture Substances 0.000 description 12
- 239000002002 slurry Substances 0.000 description 12
- 238000000576 coating method Methods 0.000 description 11
- 239000011248 coating agent Substances 0.000 description 10
- 239000011164 primary particle Substances 0.000 description 10
- 239000011163 secondary particle Substances 0.000 description 10
- 125000000524 functional group Chemical group 0.000 description 9
- 230000001276 controlling effect Effects 0.000 description 8
- 238000005245 sintering Methods 0.000 description 8
- 238000003756 stirring Methods 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- -1 iron ions Chemical class 0.000 description 7
- 229910052757 nitrogen Inorganic materials 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- 239000002033 PVDF binder Substances 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 6
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 6
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 6
- 239000008367 deionised water Substances 0.000 description 6
- 229910021641 deionized water Inorganic materials 0.000 description 6
- 238000001914 filtration Methods 0.000 description 6
- 239000011888 foil Substances 0.000 description 6
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 6
- 229910001437 manganese ion Inorganic materials 0.000 description 6
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 6
- 238000005303 weighing Methods 0.000 description 6
- 238000010306 acid treatment Methods 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 229910019142 PO4 Inorganic materials 0.000 description 4
- 239000010405 anode material Substances 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 239000010452 phosphate Substances 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 4
- 239000000725 suspension Substances 0.000 description 4
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 3
- 230000003321 amplification Effects 0.000 description 3
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 238000011065 in-situ storage Methods 0.000 description 3
- 150000002696 manganese Chemical class 0.000 description 3
- 229910017604 nitric acid Inorganic materials 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 2
- 229910010707 LiFePO 4 Inorganic materials 0.000 description 2
- 229910013870 LiPF 6 Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000032683 aging Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000004146 energy storage Methods 0.000 description 2
- 229910001447 ferric ion Inorganic materials 0.000 description 2
- YAGKRVSRTSUGEY-UHFFFAOYSA-N ferricyanide Chemical compound [Fe+3].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-].N#[C-] YAGKRVSRTSUGEY-UHFFFAOYSA-N 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 description 2
- 239000004005 microsphere Substances 0.000 description 2
- VLTRZXGMWDSKGL-UHFFFAOYSA-N perchloric acid Chemical compound OCl(=O)(=O)=O VLTRZXGMWDSKGL-UHFFFAOYSA-N 0.000 description 2
- 238000011056 performance test Methods 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000012716 precipitator Substances 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000009827 uniform distribution Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 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 description 1
- 229910015645 LiMn Inorganic materials 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910003481 amorphous carbon Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 238000001027 hydrothermal synthesis Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- FFSSRHVDYWHLLV-UHFFFAOYSA-J iron(2+) manganese(2+) oxalate Chemical compound C(C(=O)[O-])(=O)[O-].[Fe+2].[Mn+2].C(C(=O)[O-])(=O)[O-] FFSSRHVDYWHLLV-UHFFFAOYSA-J 0.000 description 1
- AWKHTBXFNVGFRX-UHFFFAOYSA-K iron(2+);manganese(2+);phosphate Chemical compound [Mn+2].[Fe+2].[O-]P([O-])([O-])=O AWKHTBXFNVGFRX-UHFFFAOYSA-K 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000002103 nanocoating Substances 0.000 description 1
- 238000007709 nanocrystallization Methods 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 239000010450 olivine Substances 0.000 description 1
- 229910052609 olivine Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 239000012286 potassium permanganate Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/362—Composites
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Composite Materials (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a lithium iron manganese phosphate composite material and a preparation method thereof, and belongs to the technical field of lithium ion batteries. The invention synthesizes a lithium iron manganese phosphate composite material, which comprises an organic acid ferromanganese precursor for synthesizing an embedded carbon nano tube by a coprecipitation reaction method, and the lithium iron manganese phosphate composite material coated by the embedded carbon nano tube and outer carbon is synthesized by high-temperature calcination. The synthesized lithium iron manganese phosphate composite material not only ensures higher compaction density, but also effectively improves the transmission efficiency of electrons/ions in the particles due to the carbon nano tubes in the particles; in the high-temperature calcination process, the crystallinity of the particles becomes high, and the carbon layer formed on the surfaces of the particles can effectively improve the conductivity of electrons/ions among the particles. When the lithium iron manganese phosphate composite material is used as a positive electrode material, good conductivity can ensure that the battery has good electrochemical performance, and the volume energy density of the battery can be improved by higher compaction density.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and particularly relates to a lithium iron manganese phosphate composite material and a preparation method thereof.
Background
LiFe in recent years y Mn 1-y PO 4 Material as LiFePO 4 And LiMnPO 4 Is of the same family as LiFePO 4 Superior structural stability, high safety and LiMnPO 4 The advantages of high operating voltage, high specific energy and the like are considered to be ideal positive electrode materials of new generation lithium ion batteries. The method is widely applied to the commercial fields of electric automobiles, electric tools, energy storage and the like. However LiFe y Mn 1-y PO 4 The material has the defects of lower electron/ion conductivity, shorter service life caused by Mn precipitation in the circulation process and the like, and greatly limits the application of the material in the advanced energy storage field with high energy density, high power and quick response.
Currently, for LiFe y Mn 1-y PO 4 The main treatment modes are as follows: (1) particle nanocrystallization, (2) design of special structure/morphology, and (3) electron/ion conductive network construction. To improve LiFe y Mn 1-y PO 4 Usually, one or more treatment modes are adopted for matching.
The invention with the authority of CN115321507B discloses a method for preparing ferromanganese phosphate by coprecipitation and application thereof, wherein ferricyanide solution, manganese salt solution and mixed solution of phosphoric acid and perchloric acid are respectively prepared, ferricyanide solution, manganese salt solution, mixed solution and alkali liquor are added into base solution in parallel flow for reaction, precipitate is obtained, namely ferromanganese phosphate, and then the precipitate is mixed with lithium hydroxide and glucose for calcination to obtain manganese-assisted carbon-coated lithium ferromanganese phosphate particles.
The patent application with publication number of CN116374981A discloses a preparation method and application of in-situ growth of lithium iron manganese phosphate on the surface of conductive carbon microspheres to form a three-dimensional conductive network, wherein the preparation method comprises the following steps: firstly, preparing conductive carbon microspheres and mixing a lithium iron manganese phosphate precursor solution, and performing a hydrothermal reaction in the next step to obtain a lithium iron manganese phosphate precursor; and (3) carrying out high-temperature sintering on the lithium iron manganese phosphate precursor to obtain the lithium iron manganese phosphate anode material.
The invention with the authority of CN111740104B discloses a preparation method of a lithium iron manganese phosphate/carbon nanotube composite anode material, and compared with the traditional method, the preparation method provided by the invention has the advantages that the iron-based catalyst is used for inducing the in-situ growth of carbon nanotubes with good dispersibility, the lithium iron phosphate/carbon nanotube composite anode material is prepared by taking the carbon nanotubes as a raw material, and potassium permanganate is added to accelerate the oxidation of iron; the material has good structural stability and thermal stability, high conductivity, smaller particle size and uniform distribution, effectively improves the cycle performance and the multiplying power performance of the lithium iron manganese phosphate material, and is beneficial to further promoting the industrialized application of the lithium iron manganese phosphate material.
The synthesis process has the advantages and disadvantages, wherein the coprecipitation method has the advantages of simple synthesis process, larger material particle size and higher compaction density, but large particles have the disadvantage of poor conductivity; the in-situ growth nanoparticle method can effectively improve the conductivity of the material, but has lower compaction density, so that the volume energy density is lower; although the carbon material composite can effectively improve the conductivity between lithium iron manganese phosphate particles, the transmission efficiency of electrons/ions in the particles cannot be improved.
Disclosure of Invention
Aiming at the defects existing in the prior art, the invention provides a lithium iron manganese phosphate composite material and a preparation method thereof, wherein a coprecipitation method is adopted to synthesize an organic acid ferromanganese precursor of an embedded carbon nano tube, and then the precursor, a lithium source, a phosphorus source and a carbon source are subjected to high-temperature calcination to finally synthesize the lithium iron manganese phosphate composite material coated by the embedded carbon nano tube and outer carbon.
The specific technical scheme of the invention is as follows:
a preparation method of a lithium iron manganese phosphate composite material comprises the steps of embedding carbon nano tubes and coating a carbon layer on the surface of the lithium iron manganese phosphate composite material, wherein the lithium iron manganese phosphate composite material comprises LiFe y Mn 1-y PO 4 Wherein y is more than or equal to 0.2 and less than or equal to 0.4,
the mass ratio of the carbon nano tube in the lithium iron manganese phosphate composite material is 0.5-1.5wt%; the mass ratio of the carbon layer in the lithium iron manganese phosphate composite material is 0.5-1.5wt%,
the preparation method comprises the following steps:
(1) Adding a manganese source and an iron source into an organic acid aqueous solution to obtain an organic acid ferromanganese mixed solution;
(2) Adding the carbon nano tube subjected to aqua regia solution modification treatment into an organic acid aqueous solution, and uniformly mixing to obtain a solution A;
(3) Adding the mixed solution of the organic acid ferromanganese obtained in the step (1) into the solution A obtained in the step (2), uniformly mixing to obtain a solution B, regulating the pH value of the solution B to be 2-5 by using ammonia water, reacting to obtain a reactant, and drying the reactant to obtain the organic acid ferromanganese embedded with the carbon nano tubes;
(4) Sequentially adding the organic acid ferromanganese, the lithium source, the phosphorus source and the carbon source of the embedded carbon nano tube obtained in the step (3) into a dispersing agent, and fully grinding to obtain mixed slurry;
(5) And (3) drying the mixed slurry obtained in the step (4), and calcining under inert gas to obtain the lithium manganese iron phosphate composite material after the calcining is finished.
Because the current method for improving conductivity is basically to coat a carbon source on the outer side of LFMP, the invention constructs a point channel in the secondary particle, uses aqua regia to carry out acid treatment on the carbon nano tube, can connect hydroxyl and carboxyl functional groups on the surface of the carbon nano tube, improves the dispersity of the carbon nano tube in an organic acid solution, can regulate and control the length-diameter ratio, specific surface area and pore volume of the carbon nano tube by controlling the acid treatment condition, and can increase the carboxyl and hydroxyl on the surface of the carbon nano tube, so that more hydroxyl and carboxyl functional groups exist on the surface of the carbon nano tube, and organic acid is used as a precipitator and a solvent, so that manganese salt and ferric salt can be effectively dissolved, the concentration of manganese ions and ferric ions in the solution can be improved, the functional groups can adsorb manganese ions and ferric ions in the solution, and the primary particles of organic acid manganese iron are induced to be uniformly distributed on the surface of the carbon nano tube to be formed, and the distribution of manganese iron atomic level is facilitated.
The primary particles are continuously stirred, aggregated and grown to finally form secondary particles with micron-sized size, and the inside of the synthesized secondary particles is provided with embedded carbon nano tubes. After high-temperature calcination, the connection between the lithium iron manganese phosphate primary particles and the carbon nano tubes and between the lithium iron manganese phosphate primary particles is firmer, the existence of the carbon nano tubes can effectively improve the transmission of electrons/ions in the material, and meanwhile, the carbon nano tubes have better toughness and elastic modulus, can effectively improve the structural stability of the lithium iron manganese phosphate secondary particles in the battery charging and discharging cycle process, and are beneficial to improving the electrochemical performance and the cycle stability of the battery. The organic acid ferromanganese precursor embedded with the carbon nano tubes is mixed and ground with the phosphorus source, the lithium source and the carbon source, so that the dispersion degree of each component can be improved, a uniform coating layer is formed on the surface of the material after the carbon source is calcined at a high temperature, the conductivity between the materials can be effectively improved by the coating layer, the precipitation of manganese ions is slowed down, and the synthesized ferromanganese phosphate lithium material has a micron-sized structure and has higher compaction density and volume energy density.
Specifically, the organic acid in the organic acid aqueous solution is at least one of ethylenediamine tetraacetic acid, polyacrylic acid, tartaric acid, citric acid and oxalic acid.
The manganese source is at least one of manganese oxalate, manganese carbonate, manganese sulfate, manganese nitrate and manganese acetate,
the iron source is at least one of ferrous oxalate, ferrous sulfate and ferrous chloride,
the molar ratio of the manganese element in the manganese source to the iron element in the iron source is 1.5-4,
the concentration of the organic acid ferromanganese mixed solution is 0.1-1mol/L.
Specifically, in the step (2), the treatment conditions of the carbon nanotubes modified by the aqua regia solution are as follows: heating in water bath at 80-95deg.C for 0.5-1.5 hr.
The surface of the carbon nano tube subjected to acid treatment has more hydroxyl and carboxyl functional groups, and the functional groups can induce primary particles to be uniformly distributed on two sides of the carbon nano tube, so that the uniform distribution of ferromanganese is facilitated. The primary particles are aggregated to form secondary particles with micron-sized size, and embedded carbon nanotubes are arranged in the synthesized secondary particles.
Even if aqua regia is used for carrying out acid treatment on the carbon nano tube, the surface of the carbon nano tube can be connected with functional groups such as carboxyl, hydroxyl and the like, the dispersity of the carbon nano tube in an organic acid solution is improved, the surface of the carbon nano tube has electronegativity after the functional groups are dissociated in the solution, manganese ions and iron ions in the organic acid solution can be adsorbed, so that when coprecipitation is carried out, a metal phase can be formed on the outer side of the carbon nano tube preferentially, organic acid ferromanganese primary particles are induced to grow on the surface of the carbon nano tube, agglomeration is carried out, and the carbon nano tube is locked in the organic acid ferromanganese precursor through continuous stirring and aging, so that organic acid ferromanganese secondary spherical particles embedded with the carbon nano tube are finally formed, and a point channel is built inside the secondary particles.
In the step (3), the reaction temperature is 55-75 ℃ and the reaction time is 4-6h;
the drying temperature is 75-95 ℃ and the drying time is 8-12 h.
In the step (4), the lithium source is at least one of lithium carbonate, lithium hydroxide, lithium phosphate and lithium dihydrogen phosphate,
the phosphorus source is at least one of phosphoric acid, monoammonium phosphate and lithium dihydrogen phosphate,
the carbon source is at least one of anhydrous glucose, sucrose, fructose, phenolic resin, polyethylene glycol and polyvinyl alcohol,
the dispersing agent is an aqueous solution of polyethylene glycol.
Polyethylene glycol affects the uniformity and the dispersibility of the lithium iron manganese phosphate anode material embedded with the carbon nano tube. The polyethylene glycol has good dispersibility, has higher polarity, can form strong interaction with solute, so that the solute is dispersed in the solvent to form a stable dispersion system, the rheological property of the suspension can be effectively improved, the stability of the suspension can be improved, the viscosity of the suspension can be reduced, and the fluidity of the suspension can be improved so as to achieve the purpose of dispersion. In addition, polyethylene glycol has good crystallization resistance, and can prevent solute from crystallizing, thereby achieving the purpose of dispersion.
The lithium source and the organic acid ferromanganese and phosphorus source embedded with the carbon nano tube are mixed according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- The addition is carried out in a ratio of 1-1.02:1.1-1.5:1.
The grinding conditions are as follows: the grinding speed is 350-450rpm/min, and the grinding time is 5-8h.
In the step (5), the calcination condition is that the temperature is kept at 600-800 ℃ for 3-10h. The sintering atmosphere is nitrogen.
The invention also provides the lithium iron manganese phosphate composite material prepared by the preparation method.
The invention also provides application of the lithium iron manganese phosphate composite material in preparation of lithium ion batteries.
The invention also provides a lithium ion battery, which comprises the lithium iron manganese phosphate composite material.
The invention has the beneficial effects that:
the invention synthesizes a lithium iron manganese phosphate composite material, which comprises an organic acid ferromanganese precursor for synthesizing an embedded carbon nano tube by a coprecipitation reaction method, and the lithium iron manganese phosphate composite material coated by the embedded carbon nano tube and outer carbon is synthesized by high-temperature calcination. The synthesized lithium iron manganese phosphate composite material not only ensures higher compaction density, but also effectively improves the transmission efficiency of electrons/ions in the particles due to the carbon nano tubes in the particles; in the high-temperature calcination process, the crystallinity of the particles becomes high, and the carbon layer formed on the surfaces of the particles can effectively improve the conductivity of electrons/ions among the particles. When the lithium iron manganese phosphate composite material is used as a positive electrode material, good conductivity can ensure that the battery has good electrochemical performance, and the volume energy density of the battery can be improved by higher compaction density.
Drawings
FIG. 1 is an SEM image of an iron manganese oxalate material with embedded carbon nanotubes according to example 1 of the present invention;
FIG. 2 is a characteristic diagram of a carbon nanotube embedded ferromanganese oxalate material according to example 1 of the present invention;
FIG. 3 is an SEM image of a lithium iron manganese phosphate composite material prepared in example 1 of the present invention; wherein the amplification is 5000 times;
FIG. 4 is an SEM image of a lithium iron manganese phosphate composite material prepared in example 1 of the present invention; wherein the amplification is 10000 times;
FIG. 5 is an SEM image of a lithium iron manganese phosphate composite material prepared in example 1 of the present invention; wherein the amplification is 50000 times;
FIG. 6 is an SEM image of a lithium iron manganese phosphate composite material prepared in example 1 of the present invention; wherein is 100000 times of magnification;
FIG. 7 is a characteristic diagram of a lithium iron manganese phosphate composite material prepared in example 1 of the present invention;
fig. 8 is a graph showing the first charge and discharge performance of the assembled battery according to example 1 of the present invention in the range of 2.0V to 4.5V, and the electrochemical performance of the assembled battery according to examples 0.1C, 0.2C, 0.5C, 1C, and 2C.
Detailed Description
Example 1
Step 1: respectively adding manganese oxalate and ferrous oxalate into an oxalic acid aqueous solution according to the mol ratio of Mn to Fe=1.5 to prepare a 1mol/L mixed solution; preparing aqua regia solution by concentrated nitric acid and concentrated hydrochloric acid according to the volume ratio of 1:3.
Step 2: placing the prepared beaker of aqua regia solution into a water bath kettle with the temperature of 80 ℃ for stirring and heating, then adding carbon nano tubes with the dosage of 0.5% of that of the lithium iron manganese phosphate composite material into the aqua regia with the temperature of 80 ℃, and heating and stirring for 0.5h. And drying the modified carbon nano tube at 75 ℃ for 12 hours, and then adding the dried carbon nano tube into an organic acid aqueous solution to form a solution A.
Step 3: and (3) adding the mixed solution obtained in the step (1) into the solution A, adding an ammonia water solution into the solution A to regulate the pH value of the solution to 2, controlling the reaction temperature to 55 ℃, and reacting for 4-6h to obtain the precipitate after the reaction is finished.
Step 4: and (3) filtering the precipitate, cleaning the precipitate for multiple times by using deionized water and ethanol, and placing the precipitate in a drying oven at 75 ℃ for 12 hours to obtain the organic acid ferromanganese powder embedded with the carbon nano tubes.
Step 5: mixing organic acid ferromanganese powder embedded with carbon nano tube with lithium carbonate and lithium dihydrogen phosphate according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- 0.5wt% anhydrous glucose of a lithium manganese iron phosphate composite material and 1.01:1.3:1 were sequentially added to an aqueous solution of polyethylene glycol, and subjected to sufficient grinding at 350rpm for 10 hours.
Step 6: and (3) placing the ground slurry at 75 ℃, drying for 12 hours, placing the dried powder in a box-type furnace, and preserving the temperature for 10 hours under the calcination condition of room temperature to 600 ℃ under the sintering atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
1wt% NMP was added dropwise to the mixture after the uniform grinding, followed by grinding to homogenize the mixture;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 70 ℃ and drying for 12 hours to obtain the anode of the lithium ion battery.
The SEM image of the organic acid ferromanganese powder embedded with the carbon nanotubes prepared in the step 4 is shown in fig. 1, and it can be seen that the carbon nanotubes which are independent and free are hardly seen, the surfaces of the carbon nanotubes are completely wrapped with manganese and iron secondary particles, so that the original carbon nanotubes are treated by aqua regia mixed acid, impurities are removed, meanwhile, the defects of five-membered rings, seven-membered rings and the surfaces of the carbon nanotubes with poor stability and two ports are easily corroded due to the strong oxidizing property of the mixed acid, thereby forming functional groups such as hydroxyl groups and carboxyl groups on the surfaces of the carbon, absorbing and capturing manganese and iron ions as ligands, and then the carbon nanotubes capturing manganese and iron ions can be singly dispersed in an organic acid ferromanganese solution, and then the manganese and iron ions on different carbon nanotubes or on different positions on the same carbon nanotube are combined, nucleated and grown to form particles, and the carbon nanotubes are uniformly embedded therein.
The lithium iron manganese phosphate composite material prepared in the step 6 is shown in a scanning electron microscope image of fig. 3-6, the morphology and the microstructure of the lithium iron manganese phosphate material prepared in the embodiment 1 are observed, the prepared sample is of a spheroid-like structure, and the average size of particles is 100-150 nm; the carbon coated on the surface of the material is uniform and complete, and the thickness of the coated carbon layer is about 1.5-3 nm;
for the lithium iron manganese phosphate material prepared in example 1The phase analysis was carried out, and the diffraction peaks and LiMn of the obtained sample were as shown in FIG. 7 0.6 Fe 0.4 PO 4 Corresponding to the standard patterns of the olivine structure belonging to the orthorhombic system; no impurity peak appears in the map, which indicates that the sample prepared in the embodiment is pure-phase lithium manganese iron phosphate; no diffraction peak for carbon was detected, indicating that carbon was present as amorphous carbon on the surface of the coating material.
Example 2
Step 1: manganese carbonate and ferrous chloride are respectively added into an aqueous solution of polyacrylic acid according to the mol ratio of Mn to Fe=2.33 to prepare a mixed solution of 0.5 mol/L; preparing aqua regia solution by concentrated nitric acid and concentrated hydrochloric acid according to the volume ratio of 1:3.
Step 2: placing the prepared beaker of aqua regia solution into a water bath kettle at 90 ℃ for stirring and heating, then adding the carbon nano tube with the dosage of 1wt% of the lithium iron manganese phosphate composite material into the aqua regia at 90 ℃, and heating and stirring for 1h. And drying the modified carbon nano tube at 85 ℃ for 10.5 hours, and then adding the dried carbon nano tube into an organic acid aqueous solution to form a solution A.
Step 3: and (3) adding the mixed solution obtained in the step (1) into the solution A, adding an ammonia water solution into the solution A to adjust the pH value of the solution to 3, controlling the reaction temperature to 65 ℃, and reacting for 5 hours to obtain the precipitate after the reaction is finished.
Step 4: and (3) filtering the precipitate, cleaning the precipitate for multiple times by using deionized water and ethanol, placing the precipitate in a drying oven at 85 ℃, and drying the precipitate for 10 hours to obtain the organic acid ferromanganese powder embedded with the carbon nano tubes.
Step 5: mixing organic acid ferromanganese powder embedded with carbon nano tube with lithium hydroxide, and ammonium dihydrogen phosphate according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- 1wt% polyvinyl alcohol of the composite material of manganese iron phosphate and lithium iron phosphate, which is 1.02:1.5:1, is added into aqueous solution of polyethylene glycol in sequence, and the mixture is fully ground under 400rpm for 8 hours.
Step 6: and (3) placing the ground slurry at 85 ℃, drying for 10 hours, placing the dried powder in a box-type furnace, calcining at room temperature to 700 ℃, then preserving the temperature for 6 hours, and sintering in the atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
dropping 3wt% NMP into the mixture after being ground, and grinding while dropping to homogenize;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 85 ℃ and drying for 10 hours to obtain the anode of the lithium ion battery.
Example 3
Step 1: manganese acetate and ferrous sulfate are respectively added into a citric acid aqueous solution according to the mol ratio of Mn to Fe=4 to prepare a mixed solution of 0.1 mol/L; preparing aqua regia solution by concentrated nitric acid and concentrated hydrochloric acid according to the volume ratio of 1:3.
Step 2: placing the prepared beaker of aqua regia solution in a water bath kettle with the temperature of 95 ℃ for stirring and heating, then adding the carbon nano tube with the dosage of 1.5% of the lithium iron manganese phosphate composite material into the aqua regia with the temperature of 95 ℃, and heating and stirring for 1.5 hours. And drying the modified carbon nano tube at 95 ℃ for 12 hours, and adding the dried carbon nano tube into an organic acid aqueous solution to form a solution A.
Step 3: and (3) adding the mixed solution obtained in the step (1) into the solution A, adding an ammonia water solution into the solution A to adjust the pH value of the solution to 5, controlling the reaction temperature to 75 ℃, and reacting for 4 hours to obtain the precipitate after the reaction is finished.
Step 4: and (3) filtering the precipitate, cleaning the precipitate for multiple times by using deionized water and ethanol, placing the precipitate in a drying oven at 95 ℃, and drying the precipitate for 8 hours to obtain the organic acid ferromanganese powder embedded with the carbon nano tubes.
Step 5: mixing organic acid ferromanganese powder embedded with carbon nano tube with lithium phosphate, and adding lithium dihydrogen phosphate according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- 1.5wt% sucrose of the lithium manganese iron phosphate composite material and 1.0:1.1:1 were added sequentially to an aqueous solution of polyethylene glycol, and subjected to sufficient grinding at 450rpm for 8 hours.
Step 6: and (3) placing the ground slurry at 95 ℃, drying for 8 hours, placing the dried powder in a box-type furnace, and preserving the temperature for 3 hours under the calcination condition of room temperature to 800 ℃ under the sintering atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
dropwise adding 5wt% NMP to the mixture after uniform grinding, and grinding while dropwise adding to carry out homogenization;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 90 ℃ and drying for 8 hours to obtain the anode of the lithium ion battery.
Comparative example 1 (carbon nanotubes were not added, outer carbon coating)
Step 1: respectively adding manganese oxalate and ferrous oxalate into an oxalic acid aqueous solution according to the mol ratio of Mn to Fe=1.5 to prepare a 1mol/L mixed solution;
step 2: and (2) adding an ammonia water solution into the mixed solution in the step (1) to adjust the pH value of the solution to 2, controlling the reaction temperature to 55 ℃ and the reaction time to 4 hours, and obtaining the precipitate after the reaction is finished.
Step 3: and filtering the precipitate, washing the precipitate with deionized water and ethanol for multiple times, and placing the precipitate in a drying oven at 75 ℃ for 12 hours to obtain the organic acid ferromanganese powder.
Step 4: in the step 3, the organic acid ferromanganese powder, lithium carbonate and lithium dihydrogen phosphate are obtained according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- 0.5wt% anhydrous glucose of a lithium manganese iron phosphate composite material and 1.01:1.3:1 were sequentially added to an aqueous solution of polyethylene glycol, and subjected to sufficient grinding at 350rpm for 10 hours.
Step 5: and (3) placing the ground slurry at 75 ℃, drying for 12 hours, placing the dried powder in a box-type furnace, and preserving the temperature for 10 hours under the calcination condition of room temperature to 600 ℃ under the sintering atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
1wt% NMP was added dropwise to the mixture after the uniform grinding, followed by grinding to homogenize the mixture;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 70 ℃ and drying for 12 hours to obtain the anode of the lithium ion battery.
Comparative example 2 (addition of carbon nanotubes without aqua regia treatment, carbon coating)
Step 1: manganese oxalate and ferrous oxalate are respectively added into an ethylenediamine tetraacetic acid aqueous solution according to the mol ratio of Mn to Fe=1.5 to prepare a 1mol/L mixed solution.
Step 2: and (3) adding an ammonia water solution into the mixed solution in the step (1) to adjust the pH value of the solution to 2, controlling the reaction temperature to 55 ℃ and the reaction time to 6 hours, and obtaining the precipitate after the reaction is finished.
Step 3: and filtering the precipitate, washing the precipitate with deionized water and ethanol for multiple times, and placing the precipitate in a drying oven at 75 ℃ for 12 hours to obtain the organic acid ferromanganese powder.
Step 4: mixing organic acid ferromanganese powder with lithium carbonate and lithium dihydrogen phosphate according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- 0.5wt% anhydrous glucose of a lithium manganese iron phosphate composite material and 1.01:1.3:1 were sequentially added to an aqueous solution of polyethylene glycol, and subjected to sufficient grinding at 350rpm for 10 hours.
Step 5: and (3) placing the ground slurry at 75 ℃, drying for 12 hours, placing the dried powder in a box-type furnace, and preserving the temperature for 10 hours under the calcination condition of room temperature to 600 ℃ under the sintering atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
1wt% NMP was added dropwise to the mixture after the uniform grinding, followed by grinding to homogenize the mixture;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 70 ℃ and drying for 12 hours to obtain the anode of the lithium ion battery.
Comparative example 3 (addition of carbon nanotubes, outer layer without carbon coating)
Step 1: respectively adding manganese oxalate and ferrous oxalate into an oxalic acid aqueous solution according to the mol ratio of Mn to Fe=1.5 to prepare a 1mol/L mixed solution;
step 2: and (3) drying the carbon nano tube with the dosage of 0.5% of that of the lithium iron manganese phosphate composite material for 12 hours at the temperature of 75 ℃, and then adding the dried carbon nano tube into an organic acid aqueous solution to form a solution A.
Step 3: and (3) adding the mixed solution in the step (1) into the solution A, adding an ammonia water solution into the solution A to regulate the pH value of the solution to 2, controlling the reaction temperature to 55 ℃, and reacting for 4 hours to obtain the precipitate after the reaction is finished.
Step 4: and (3) filtering the precipitate, cleaning the precipitate for multiple times by using deionized water and ethanol, and placing the precipitate in a drying oven at 75 ℃ for 12 hours to obtain the organic acid ferromanganese powder embedded with the carbon nano tubes.
Step 5: mixing organic acid ferromanganese powder embedded with carbon nano tube with lithium carbonate and lithium dihydrogen phosphate according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- Sequentially adding the mixture to an aqueous solution of polyethylene glycol in a ratio of (1.01:1.3:1), and sufficiently grinding at 350rpm for 10 hours.
Step 6: and (3) placing the ground slurry at 75 ℃, drying for 12 hours, placing the dried powder in a box-type furnace, and preserving the temperature for 10 hours under the calcination condition of room temperature to 600 ℃ under the sintering atmosphere of nitrogen. And (5) obtaining the lithium iron manganese phosphate composite material after the calcination is finished.
Grinding the sintered lithium iron manganese phosphate composite material, and weighing and mixing the ground lithium iron manganese phosphate composite material, SP and PVDF according to the mass ratio of 8:1:1, and uniformly grinding;
1wt% NMP was added dropwise to the mixture after the uniform grinding, followed by grinding to homogenize the mixture;
uniformly coating the grinded slurry on an aluminum foil to prepare an electrode plate;
and (5) putting the coated electrode plate into a vacuum environment at 70 ℃ and drying for 12 hours to obtain the anode of the lithium ion battery.
Test example 1
Electrode sheets prepared according to examples 1 to 3 and comparative examples 1 to 3 were used as the negative electrode; the separator is a Celgard2400 polypropylene porous membrane; the electrolyte is a solution composed of EC, DMC and EMC according to the mass ratio of 1:1:1, and the solute is LiPF 6 ，LiPF 6 The concentration of (2) is 1.0mol/L; inside the glove box, 2023 type button cell was assembled. The battery was subjected to charge-discharge cycle performance test, continuous charge-discharge was performed at current densities of 0.1C, 0.2C, 0.5C, 1C and 2C in the cutoff voltage range of 2.0 to 4.5V, and electrochemical performance test results were shown in table 1 for discharge capacities at different rates.
As can be seen from the data in table 1, comparison of examples 1 to 3 shows that the organic acid ferromanganese has optimum discharge performance with ferromanganese ratio=1.5.
According to the method, when a lithium manganese iron phosphate precursor is prepared, carbon nanotubes subjected to aqua regia treatment are added, organic acid is used as a precipitator and a solvent, the concentration of manganese ions and iron ions in a solution is effectively improved, an organic acid ferromanganese mixed solution is formed, carbon nanotubes induce primary particles of organic acid ferromanganese to be molded on the surfaces of the carbon nanotubes in coprecipitation, the secondary particles of organic acid ferromanganese embedded with the carbon nanotubes are formed by continuously stirring and aging, the precursor, a lithium source and a carbon source are sufficiently ground, and the discharge capacity of the embodiment 1 under different multiplying power of 0.1C, 0.2C, 0.5C, 1C, 2C and the like is obviously improved compared with the comparative example (figure 8), and the specific discharge capacities are 152.7mAh/g, 147.5mAh/g, 144.1mAh/g, 139.6mAh/g and 134.2mAh/g respectively.
By comparing examples 1-3 with comparative examples 1-3, it can be seen that the organic acid ferromanganese precursor embedded with aqua regia treated carbon nanotubes can significantly improve the battery performance of the lithium ferromanganese phosphate positive electrode material.
Table 1 discharge capacities (mAh/g) of examples and comparative examples at different magnifications
From the above data, it can be seen that: the carbon nano tube embedded with aqua regia treatment can regulate and control the length-diameter ratio, specific surface area, pore volume and surface functional group quantity of the carbon nano tube by controlling acid treatment conditions, manganese ions and iron ions on the surface of the carbon nano tube can reach the average distribution of molecular level, and after high-temperature calcination, the connection between the primary particles of lithium iron manganese phosphate and the carbon nano tube and the primary particles of lithium iron manganese phosphate is firmer. The existence of the carbon nano tube can effectively improve the transmission of electron ions in the material, effectively improve the internal conductivity of the lithium iron manganese phosphate material, and simultaneously, as the carbon nano tube structure has better toughness and elastic quantity, the structural stability of the lithium iron manganese phosphate secondary particles in the charge-discharge cycle process of the battery can be effectively improved, the volume resistivity of the lithium iron manganese phosphate material is effectively reduced, and the internal electron conductivity and Li of the material are improved + The transmission rate is favorable for improving the electrochemical performance and the cycling stability of the battery.
Claims (10)
1. The preparation method of the lithium iron manganese phosphate composite material is characterized in that the lithium iron manganese phosphate composite material is a lithium iron manganese phosphate material embedded carbon nanotube and a surface coated carbon layer, and the lithium iron manganese phosphate material comprises LiFe y Mn 1-y PO 4 Wherein y is more than or equal to 0.2 and less than or equal to 0.4,
the mass ratio of the carbon nano tube in the lithium iron manganese phosphate composite material is 0.5-1.5wt%; the mass ratio of the carbon layer in the lithium iron manganese phosphate composite material is 0.5-1.5wt%,
the preparation method comprises the following steps:
(1) Adding a manganese source and an iron source into an organic acid aqueous solution to obtain an organic acid ferromanganese mixed solution;
(2) Adding the carbon nano tube subjected to aqua regia solution modification treatment into an organic acid aqueous solution, and uniformly mixing to obtain a solution A;
(3) Adding the mixed solution of the organic acid ferromanganese obtained in the step (1) into the solution A obtained in the step (2), uniformly mixing to obtain a solution B, regulating the pH value of the solution B to be 2-5 by using ammonia water, reacting to obtain a reactant, and drying the reactant to obtain the organic acid ferromanganese embedded with the carbon nano tubes;
(4) Sequentially adding the organic acid ferromanganese, the lithium source, the phosphorus source and the carbon source of the embedded carbon nano tube obtained in the step (3) into a dispersing agent, and fully grinding to obtain mixed slurry;
(5) And (3) drying the mixed slurry obtained in the step (4), and calcining under inert gas to obtain the lithium manganese iron phosphate composite material after the calcining is finished.
2. The method for preparing a lithium iron manganese phosphate composite material according to claim 1, wherein the organic acid in the organic acid aqueous solution is at least one of ethylenediamine tetraacetic acid, polyacrylic acid, tartaric acid, citric acid and oxalic acid.
3. The method for preparing the lithium iron manganese phosphate composite material according to claim 1, wherein the manganese source is at least one of manganese oxalate, manganese carbonate, manganese sulfate, manganese nitrate and manganese acetate,
the iron source is at least one of ferrous oxalate, ferrous sulfate and ferrous chloride,
the molar ratio of the manganese element in the manganese source to the iron element in the iron source is 1.5-4,
the concentration of the organic acid ferromanganese mixed solution is 0.1-1mol/L.
4. The method for preparing a lithium iron manganese phosphate composite material according to claim 1, wherein in the step (2), the carbon nanotubes modified with the aqua regia solution are treated under the following conditions: heating in water bath at 80-95deg.C for 0.5-1.5 hr.
5. The method for preparing a lithium iron manganese phosphate composite material according to claim 1, wherein in the step (3), the reaction temperature is 55-75 ℃ and the reaction time is 4-6h;
the drying temperature is 75-95 ℃ and the drying time is 8-12 h.
6. The method for producing a lithium iron manganese phosphate composite material according to claim 1, wherein in the step (4), the lithium source is at least one of lithium carbonate, lithium hydroxide, lithium phosphate and lithium dihydrogen phosphate,
the phosphorus source is at least one of phosphoric acid, monoammonium phosphate and lithium dihydrogen phosphate,
the carbon source is at least one of anhydrous glucose, sucrose, fructose, phenolic resin, polyethylene glycol and polyvinyl alcohol,
the lithium source and the organic acid ferromanganese and phosphorus source embedded with the carbon nano tube are mixed according to the mass ratio of nLi to n (Mn+Fe) to nPO 4 3- The addition is carried out in a ratio of 1-1.02:1.1-1.5:1.
7. The method for preparing a lithium iron manganese phosphate composite material according to claim 1, wherein in the step (5), the calcination condition is to keep the temperature at 600-800 ℃ for 3-10 hours.
8. The lithium iron manganese phosphate composite material prepared by the preparation method according to any one of claims 1 to 7.
9. The use of the lithium iron manganese phosphate composite material according to claim 8 in the preparation of lithium ion batteries.
10. A lithium ion battery comprising the lithium iron manganese phosphate composite material of claim 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311443555.9A CN117558883A (en) | 2023-10-31 | 2023-10-31 | Lithium iron manganese phosphate composite material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311443555.9A CN117558883A (en) | 2023-10-31 | 2023-10-31 | Lithium iron manganese phosphate composite material and preparation method thereof |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117558883A true CN117558883A (en) | 2024-02-13 |
Family
ID=89810142
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311443555.9A Pending CN117558883A (en) | 2023-10-31 | 2023-10-31 | Lithium iron manganese phosphate composite material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117558883A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118495493A (en) * | 2024-05-09 | 2024-08-16 | 蜂巢能源科技股份有限公司 | Lithium iron manganese phosphate positive electrode material, and preparation method and application thereof |
| CN119297266A (en) * | 2024-10-15 | 2025-01-10 | 湖北亿纬动力有限公司 | Positive electrode material and preparation method thereof, positive electrode sheet and battery |
| CN120039853A (en) * | 2025-04-25 | 2025-05-27 | 江苏时代新能源科技有限公司 | Ferromanganese phosphate precursor, lithium ferromanganese phosphate and preparation method thereof, battery monomer, battery device and electricity utilization device |
| CN120136062A (en) * | 2025-03-12 | 2025-06-13 | 四川大学 | Preparation method of ultrafine lithium manganese iron phosphate nanoparticles embedded in a three-dimensional porous carbon framework |
| CN121331804A (en) * | 2025-10-23 | 2026-01-13 | 湖南华兴锂电新能源有限责任公司 | A lithium manganese iron phosphate cathode material and its preparation method for pure power batteries |
-
2023
- 2023-10-31 CN CN202311443555.9A patent/CN117558883A/en active Pending
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118495493A (en) * | 2024-05-09 | 2024-08-16 | 蜂巢能源科技股份有限公司 | Lithium iron manganese phosphate positive electrode material, and preparation method and application thereof |
| CN119297266A (en) * | 2024-10-15 | 2025-01-10 | 湖北亿纬动力有限公司 | Positive electrode material and preparation method thereof, positive electrode sheet and battery |
| CN120136062A (en) * | 2025-03-12 | 2025-06-13 | 四川大学 | Preparation method of ultrafine lithium manganese iron phosphate nanoparticles embedded in a three-dimensional porous carbon framework |
| CN120039853A (en) * | 2025-04-25 | 2025-05-27 | 江苏时代新能源科技有限公司 | Ferromanganese phosphate precursor, lithium ferromanganese phosphate and preparation method thereof, battery monomer, battery device and electricity utilization device |
| CN121331804A (en) * | 2025-10-23 | 2026-01-13 | 湖南华兴锂电新能源有限责任公司 | A lithium manganese iron phosphate cathode material and its preparation method for pure power batteries |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP7493105B2 (en) | Lithium manganese iron phosphate precursor, lithium manganese iron phosphate positive electrode material and method for producing same, electrode material, electrode, and lithium ion battery | |
| KR102894704B1 (en) | Method for producing lithium manganese iron phosphate, cathode material and lithium ion battery | |
| CN100340018C (en) | Lithium transition-metal phosphate powder for rechargeable batteries | |
| CN101268572B (en) | Method for producing positive electrode active material and nonaqueous electrolyte battery using same | |
| CN106876705B (en) | Preparation method of in-situ synthesized carbon/carbon nanotube coated lithium iron phosphate composite material | |
| CN105990562B (en) | A kind of the nano lithium iron manganese composite material and preparation method and application of core-shell structure | |
| CN117558883A (en) | Lithium iron manganese phosphate composite material and preparation method thereof | |
| CN102969494B (en) | Lithium nickel manganese oxide composite material, its preparation method and lithium ion battery | |
| CN113072049A (en) | Preparation method of high-compaction-density lithium manganese iron phosphate/carbon composite positive electrode material | |
| EP4439716A1 (en) | Positive electrode material and preparation method therefor | |
| CN114335480A (en) | Core-shell carbon-coated doped lithium iron phosphate, and preparation method and application thereof | |
| CN103403932A (en) | Electrode active substance and method for producing same | |
| CN116053466A (en) | Lithium iron manganese phosphate positive electrode material, preparation method thereof, electrode material, electrode and lithium ion battery | |
| CN114566647A (en) | Calcium phosphate coated high-nickel ternary cathode material and preparation method and application thereof | |
| CN117886292A (en) | A kind of ferromanganese phosphate precursor and its preparation method and application | |
| CN117525317A (en) | Manganese-assisted carbon-coated lithium iron manganese phosphate material and preparation method thereof | |
| CN119008888A (en) | Carbon-coated lithium iron manganese phosphate positive electrode material, preparation method, positive electrode plate and battery | |
| CN104993133A (en) | A kind of preparation method of LiMnxFe1-xPO4/C composite material modified by graphene | |
| JP6070882B1 (en) | Lithium ion secondary battery electrode material and method for producing the same, lithium ion secondary battery | |
| KR102273771B1 (en) | Cathode active materials for lithium secondary batteries and lithium secondary batteries comprising the same | |
| CN106207164A (en) | The preparation method of iron manganese phosphate for lithium composite | |
| CN103178267A (en) | Method for preparing nano/microstructure lithium manganese phosphate/carbon composite cathode material | |
| CN111653782A (en) | Positive electrode material and preparation method and application thereof | |
| CN116692814A (en) | Lithium iron manganese phosphate composite material and preparation method and application thereof | |
| KR102172027B1 (en) | Method for preparation of lithium transition metal phosphate and lithium transition metal phosphate manufactured by the same |
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 |