CN115974031A - High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery - Google Patents
High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery Download PDFInfo
- Publication number
- CN115974031A CN115974031A CN202211239708.3A CN202211239708A CN115974031A CN 115974031 A CN115974031 A CN 115974031A CN 202211239708 A CN202211239708 A CN 202211239708A CN 115974031 A CN115974031 A CN 115974031A
- Authority
- CN
- China
- Prior art keywords
- iron phosphate
- lithium
- lithium iron
- carbon source
- particle size
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- GELKBWJHTRAYNV-UHFFFAOYSA-K lithium iron phosphate Chemical compound [Li+].[Fe+2].[O-]P([O-])([O-])=O GELKBWJHTRAYNV-UHFFFAOYSA-K 0.000 title claims abstract description 96
- 238000005056 compaction Methods 0.000 title claims abstract description 27
- 239000007774 positive electrode material Substances 0.000 title claims abstract description 20
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 title claims abstract description 16
- 229910001416 lithium ion Inorganic materials 0.000 title claims abstract description 15
- 238000002360 preparation method Methods 0.000 title claims abstract description 13
- 239000002245 particle Substances 0.000 claims abstract description 57
- WBJZTOZJJYAKHQ-UHFFFAOYSA-K iron(3+) phosphate Chemical compound [Fe+3].[O-]P([O-])([O-])=O WBJZTOZJJYAKHQ-UHFFFAOYSA-K 0.000 claims abstract description 48
- 229910000398 iron phosphate Inorganic materials 0.000 claims abstract description 47
- 239000002243 precursor Substances 0.000 claims abstract description 33
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 28
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 28
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000010406 cathode material Substances 0.000 claims abstract description 20
- 238000000227 grinding Methods 0.000 claims abstract description 19
- 238000002156 mixing Methods 0.000 claims abstract description 19
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052744 lithium Inorganic materials 0.000 claims abstract description 18
- 238000001694 spray drying Methods 0.000 claims abstract description 18
- 238000012216 screening Methods 0.000 claims abstract description 11
- 239000010405 anode material Substances 0.000 claims abstract description 10
- 239000002994 raw material Substances 0.000 claims abstract description 5
- 230000001681 protective effect Effects 0.000 claims abstract description 4
- 239000002904 solvent Substances 0.000 claims abstract description 4
- 239000000843 powder Substances 0.000 claims description 21
- 239000002202 Polyethylene glycol Substances 0.000 claims description 19
- 229920001223 polyethylene glycol Polymers 0.000 claims description 19
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 claims description 18
- 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 16
- 239000008103 glucose Substances 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 15
- 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 14
- 229930006000 Sucrose Natural products 0.000 claims description 14
- 239000005720 sucrose Substances 0.000 claims description 14
- XGZVUEUWXADBQD-UHFFFAOYSA-L lithium carbonate Chemical compound [Li+].[Li+].[O-]C([O-])=O XGZVUEUWXADBQD-UHFFFAOYSA-L 0.000 claims description 11
- 229910052808 lithium carbonate Inorganic materials 0.000 claims description 11
- 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 9
- XIXADJRWDQXREU-UHFFFAOYSA-M lithium acetate Chemical compound [Li+].CC([O-])=O XIXADJRWDQXREU-UHFFFAOYSA-M 0.000 claims description 7
- IIPYXGDZVMZOAP-UHFFFAOYSA-N lithium nitrate Chemical compound [Li+].[O-][N+]([O-])=O IIPYXGDZVMZOAP-UHFFFAOYSA-N 0.000 claims description 6
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 5
- 239000007921 spray Substances 0.000 claims description 4
- YNQRWVCLAIUHHI-UHFFFAOYSA-L dilithium;oxalate Chemical compound [Li+].[Li+].[O-]C(=O)C([O-])=O YNQRWVCLAIUHHI-UHFFFAOYSA-L 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 9
- 238000012360 testing method Methods 0.000 description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- 239000002002 slurry Substances 0.000 description 8
- 230000000052 comparative effect Effects 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 229910052759 nickel Inorganic materials 0.000 description 5
- 102220043159 rs587780996 Human genes 0.000 description 5
- 238000004080 punching Methods 0.000 description 4
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 239000002033 PVDF binder Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 239000006260 foam Substances 0.000 description 2
- 239000011888 foil Substances 0.000 description 2
- 229920002981 polyvinylidene fluoride Polymers 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 101100008048 Caenorhabditis elegans cut-4 gene Proteins 0.000 description 1
- 239000005955 Ferric phosphate Substances 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 229940032958 ferric phosphate Drugs 0.000 description 1
- 229910000399 iron(III) phosphate Inorganic materials 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 210000002268 wool Anatomy 0.000 description 1
Images
Classifications
-
- 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
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention provides a high-compaction lithium iron phosphate positive electrode material and a preparation method thereof, wherein the method comprises the following steps: (1) Selecting large-particle uncrushed iron phosphate, wherein the particle size of the iron phosphate is 20-25 mu m, and if the total mass of the raw material of the lithium iron phosphate positive electrode material is 100%, the content of the large-particle uncrushed iron phosphate accounts for 100%; (2) Uniformly mixing the iron phosphate with a lithium source, a carbon source and a solvent, grinding, and spray-drying to obtain a lithium iron phosphate precursor, wherein the grinding is carried out until the median particle size D50 is less than 0.5 mu m, and the rotating speed of an atomizing wheel of a spray drying tower is 18000rmp-19500rmp in the spray drying process; (3) And roasting, crushing, screening and demagnetizing the lithium iron phosphate precursor in a protective atmosphere to obtain the high-compaction lithium iron phosphate anode material. Also provides a lithium ion battery using the lithium iron phosphate cathode material.
Description
Technical Field
The invention belongs to the technical field of new energy positive electrode materials, and particularly relates to a high-compaction lithium iron phosphate positive electrode material, a preparation method of the high-compaction lithium iron phosphate positive electrode material and a lithium ion battery prepared by applying the lithium iron phosphate positive electrode material.
Background
In recent years, with the increasing influence of fossil energy on the global environment, clean energy is being widely used as a substitute, and a new energy battery, which is a main component of clean energy, is becoming the first choice for storing electric energy in the fields of passenger cars, buses, and energy storage.
At present, a new energy battery mainly comprises a lithium iron phosphate battery, a ternary battery and a high-nickel battery, wherein the lithium iron phosphate battery is difficult to decompose due to a stable P-O bond in a positive electrode material, and does not collapse and generate heat or form a strong oxidizing substance like other positive electrode materials even at high temperature or during overcharge, so that the lithium iron phosphate battery has good safety.
However, with the increasing national requirement for endurance mileage, the demand for lithium iron phosphate with high compaction density is increasing, and the powder compaction of lithium iron phosphate is required to be more than 2.3 g/mL.
Therefore, the method for preparing the lithium iron phosphate cathode material has a far-reaching significance for the development of the industry and is one of the research hotspots in the field.
Disclosure of Invention
Therefore, the invention aims to provide a preparation method of a lithium iron phosphate cathode material with low cost and simple and convenient preparation, and the compaction density of the lithium iron phosphate cathode material prepared by the method and the capacity of a lithium ion battery prepared by applying the lithium iron phosphate cathode material are improved.
The invention provides a preparation method of a high-compaction lithium iron phosphate anode material, which comprises the following steps:
(1) Selecting large-particle uncrushed iron phosphate, wherein the particle size of the iron phosphate is 20-25 mu m, and the content of the large-particle uncrushed iron phosphate accounts for 100% of the total mass of the iron phosphate as a raw material of the lithium iron phosphate positive electrode material.
(2) Uniformly mixing the iron phosphate with a lithium source, a carbon source and a solvent, grinding, and spray-drying to obtain a lithium iron phosphate precursor, wherein the grinding is carried out until the median particle diameter D50 is less than 0.5 mu m, and the rotating speed of an atomizing wheel of a spray drying tower is 18000rmp-19500rmp in the spray drying process;
(3) And roasting, crushing, screening and demagnetizing the lithium iron phosphate precursor in a protective atmosphere to obtain the high-compaction lithium iron phosphate anode material.
Preferably, in the step (2), the spray particle size is controlled to be 15-25 μm by adjusting the rotation speed of the atomizing wheel of the spray drying tower.
Preferably, in the step (2), the lithium source includes any one of lithium carbonate, lithium hydroxide, lithium nitrate, lithium oxalate or lithium acetate or a combination of at least two thereof.
Preferably, in the step (2), the lithium source and the iron phosphate are mixed according to the ratio of lithium element: the molar ratio of the iron element is (0.95-1.05): 1.
Preferably, in the step (2), the carbon source is one or a mixed carbon source of two or more of glucose, sucrose and polyethylene glycol, and when the carbon source is a mixed carbon source, the carbon source is a mixture of glucose and polyethylene glycol in a mass ratio of 1:2 or mixing the sucrose and the polyethylene glycol according to a mass ratio of 1:1 or mixing sucrose, glucose and polyethylene glycol according to a mass ratio of 1:1:2 mixed carbon source.
Preferably, in the step (2), the carbon source is added according to 10% -15% of the mass of the lithium iron phosphate precursor.
Preferably, in step (2), the grinding is carried out until the median particle diameter is 0.35 μm < D50 < 0.5. Mu.m.
Preferably, in the step (3), the heating rate of the roasting is 2-20 ℃/min, the roasting temperature is 720-780 ℃, and the roasting time is 6-15 h.
The powder compaction density of the lithium iron phosphate anode material is more than 2.55g/cm 3 。
The lithium ion battery is applied to the lithium iron phosphate cathode material, and 0.1C discharge of the lithium ion battery is 158-163 mAh/g.
Compared with the prior art, the invention has the following beneficial effects:
(1) The invention uses large particlesMixing a crushed ferric phosphate raw material with a lithium source, grinding to a certain median particle size, then spray-drying, adjusting the spray particle size by controlling the rotating speed of an atomizing wheel in the spray-drying process to obtain a small-particle-size lithium iron phosphate precursor, and roasting, crushing, screening and demagnetizing to obtain the high-compaction-density lithium iron phosphate cathode material, wherein the powder compaction density of the lithium iron phosphate cathode material is 2.55g/cm 3 The above.
(2) The button lithium ion battery prepared by using the high-compaction-density lithium iron phosphate prepared by the invention as the positive active material has excellent electrochemical performance, high specific capacity and good cycle performance, and the 0.1C discharge is 158-163 mAh/g.
(3) The method for preparing the lithium iron phosphate with high compaction density and high capacity has simple process and strong operability, directly applies the large-particle iron phosphate which is not crushed, has lower process cost, can meet the requirement of the current industrial field on the compaction density of the lithium iron phosphate cathode material, can provide good cost advantage, and has wide application prospect.
Drawings
FIG. 1 is an SEM image of large particle, unpulverized iron phosphate used in example 3 of the present invention.
Detailed Description
The technical solution of the present invention is further described below by way of specific embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments in the present application without making any creative effort belong to the protection scope of the present application.
The invention provides a preparation method of a high-compaction lithium iron phosphate anode material, which comprises the following steps:
selecting large-particle uncrushed iron phosphate, wherein the particle size of the iron phosphate is 20-25 mu m, and the content of the large-particle uncrushed iron phosphate accounts for 100% of the total mass of the iron phosphate as a raw material of the lithium iron phosphate positive electrode material.
Uniformly mixing the iron phosphate with a lithium source, a carbon source and a solvent, grinding, and spray-drying to obtain a lithium iron phosphate precursor, wherein the grinding is carried out until the median particle size D50 is less than 0.5 mu m, and the rotating speed of an atomizing wheel of a spray drying tower is 18000rmp-19500rmp in the spray drying process;
and (3) roasting, crushing, screening and demagnetizing the lithium iron phosphate precursor in a protective atmosphere to obtain the high-compaction lithium iron phosphate anode material.
Wherein, in the step (2), the lithium source comprises any one of lithium carbonate, lithium hydroxide, lithium nitrate, lithium oxalate or lithium acetate or a combination of at least two of the above.
The lithium source and the iron phosphate are prepared by mixing the following lithium elements: the molar ratio of the iron element is (0.95-1.05): 1.
The carbon source is one or more than two mixed carbon sources of glucose, sucrose and polyethylene glycol. That is, the carbon source may be a single carbon source or a mixed carbon source. When the carbon source is a mixed carbon source, the carbon source is prepared by mixing glucose and polyethylene glycol according to a mass ratio of 1:2 or mixing sucrose and polyethylene glycol according to a mass ratio of 1:1 or mixing sucrose, glucose and polyethylene glycol according to a mass ratio of 1:1:2 mixed carbon source.
The carbon source is added according to 10-15% of the mass of the lithium iron phosphate precursor.
The grinding is preferably carried out until the median particle size is 0.35 μm < D50 < 0.5. Mu.m. After the grinding is finished, spray drying is carried out, and the rotating speed of an atomizing wheel of the spray drying tower is adjusted to be 18000rmp-19500rmp, so that the small spray particle size is 15-25 mu m.
In the step (3), the heating rate of the roasting is 2-20 ℃/min, the roasting temperature is 720-780 ℃, and the roasting time is 6-15 h.
The powder compaction density of the lithium iron phosphate anode material prepared by the method is more than 2.55g/cm 3 。
The lithium ion battery prepared by the lithium iron phosphate anode material has 0.1C discharge of 158-163 mAh/g.
The following specific examples are presented to further illustrate the invention.
Example 1
(1) Large particles of uncrushed iron phosphate having a particle size of 22.3 μm were selected.
(2) Mixing lithium carbonate and iron phosphate according to a Li to Fe molar ratio of 1:1, adding glucose accounting for 15% of the weight of the lithium iron phosphate precursor, mixing, adding pure water according to 50% of the total mass of the materials (namely the lithium carbonate, the iron phosphate and the glucose), grinding for 3h, taking out slurry, testing the particle size of the slurry D50=0.45 μm, and obtaining the lithium iron phosphate precursor powder with the particle size of 22 μm through the rotation speed of an atomizing wheel of 18542 rpm.
(3) Adding the obtained lithium iron phosphate precursor powder into N 2 Heating at a heating rate of 2 ℃/min in the atmosphere, keeping the temperature at 750 ℃ for 8h to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Example 2
(1) Large-sized unpulverized iron phosphate particles having a particle size of 22.06 μm were selected.
(2) Mixing lithium carbonate and iron phosphate according to a molar ratio of Li to Fe of 1:1, adding pure water accounting for 12% of the weight of the lithium iron phosphate precursor (the mass ratio of glucose to polyethylene glycol is 1:2), grinding according to 50% of the total mass of the materials (namely lithium carbonate, iron phosphate, glucose and polyethylene glycol), taking out slurry after 4.5 hours, testing the particle size of the slurry D50=0.40 μm, and obtaining the particle size of the lithium iron phosphate precursor powder of 19 μm through an atomizing wheel rotating speed of 18802 rpm.
(3) The obtained lithium iron phosphate precursor powder is added into N 2 Heating at a heating rate of 10 ℃/min in the atmosphere, keeping the temperature of 770 ℃ for 8.5 hours to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Example 3
(1) Large particles of uncrushed iron phosphate having a particle size of 21.17 μm were selected, and the SEM image thereof is shown in FIG. 1.
(2) Lithium carbonate, lithium hydroxide and iron phosphate are mixed according to a molar ratio of 0.225:0.5:1, adding pure water accounting for 13% of the weight of the lithium iron phosphate precursor (the mass ratio of glucose to polyethylene glycol is 1:2), mixing, adding pure water according to 50% of the total mass of materials (namely lithium carbonate, lithium hydroxide, iron phosphate, glucose, polyethylene glycol and pure water), grinding for 4.5 hours, taking out slurry, testing the particle size D50=0.42 μm, and obtaining the lithium iron phosphate precursor powder with the particle size of 25 μm through the rotation speed of an atomizing wheel in 18602 rpm.
(3) The obtained lithium iron phosphate precursor powder is added into N 2 Heating at a heating rate of 8 ℃/min in the atmosphere, keeping the temperature at 765 ℃ for 9.5 hours to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Example 4
(1) Large-sized unpulverized iron phosphate particles having a particle size of 21.55 μm were selected.
(2) Lithium carbonate, lithium acetate and iron phosphate are mixed according to a molar ratio of 0.325:0.35:1, adding sucrose accounting for 14% of the weight of the lithium iron phosphate precursor, mixing, adding pure water according to 50% of the total mass of the materials (namely lithium carbonate, lithium acetate, iron phosphate and sucrose), grinding, taking out slurry after 3.5h, testing the particle size D50=0.48 μm, and obtaining the particle size of the lithium iron phosphate precursor powder body to be 21.5 μm through the rotation speed of an atomizing wheel at 18790 rpm.
(3) Adding the obtained lithium iron phosphate precursor powder into N 2 Heating at a heating rate of 8 ℃/min in the atmosphere, keeping the temperature at 775 ℃ for 9.5 hours to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Example 5
(1) Large-sized unpulverized iron phosphate particles having a particle size of 21.79 μm were selected.
(2) Mixing lithium acetate and iron phosphate according to a molar ratio of 0.98:1, adding pure water accounting for 13.5 percent of the weight of the lithium iron phosphate precursor (the mass ratio of sucrose to polyethylene glycol is 1:1), mixing, grinding 50 percent of the total mass of the materials (namely lithium acetate, iron phosphate, sucrose and polyethylene glycol) for 5.5 hours, taking out slurry, testing the particle size D50=0.38 mu m, and obtaining the lithium iron phosphate precursor powder with the particle size of 16.5 mu m through the rotation speed of an atomizing wheel of 19412 rpm.
(3) Adding the obtained lithium iron phosphate precursor powder into N 2 Heating at a heating rate of 15 ℃/min in the atmosphere, keeping the temperature of 755 ℃ for 9.0 hours to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Example 6
(1) Large particles of uncrushed iron phosphate having a particle size of 22.6 μm were selected.
(2) Lithium hydroxide and iron phosphate are added according to a molar ratio of 1.02:1, adding pure water accounting for 12.5% of the weight of the lithium iron phosphate precursor (the mass ratio of sucrose, glucose and polyethylene glycol is 1.
(3) Adding the obtained lithium iron phosphate precursor powder into N 2 Heating at a heating rate of 12 ℃/min in the atmosphere, keeping the temperature at 745 ℃ for 10.5 hours to obtain sintered lithium iron phosphate, and crushing, screening and demagnetizing the sintered lithium iron phosphate to obtain the final lithium iron phosphate cathode material.
Comparative example 1
Referring to example 3, the difference is that the iron phosphate is a conventional iron phosphate with a particle size of 2.5 μm after being crushed, and the particle size of the obtained lithium iron phosphate precursor powder is 37.5 μm.
Comparative example 2
Referring to example 3, the difference is that the iron phosphate is a conventional iron phosphate with a particle size of 2.65 μm after being crushed, and the particle size of the lithium iron phosphate precursor powder is 38.5 μm by an atomizing wheel rotating speed of 15320 rpm.
Comparative example 3
Referring to example 3, the difference is that the iron phosphate is a conventional iron phosphate with a particle size of 2.75 μm after being pulverized, and the particle size of the obtained lithium iron phosphate precursor powder is 42 μm by using an atomizing wheel with a rotation speed of 15750 rpm.
Comparative example 4
Referring to example 3, the difference is that the iron phosphate is not crushed and has a large particle size of 23 μm, and the particle size of the precursor powder of the lithium iron phosphate is 40 μm by the rotation speed of the atomizing wheel at 17000 rpm.
Performance testing
Preparation of button type lithium ion battery
1. Preparation of conductive gel (NMP: PVDF: SP = 26.5. 159 plus or minus 0.005g of NMP is weighed in a 500ml beaker, pre-stirred at 850r/min, then 6 plus or minus 0.003g of PVDF is added, stirred at 2000r/min until no particles are transparent, then 6 plus or minus 0.003gSP is added, and stirring is continued for 30min; 5.7. + -. 0.001g of conductive adhesive and 3.6. + -. 0.001g of sample are added into the dispersion cup. Dispersing the dispersing cup in a dispersing machine according to the set dispersing parameters (850rm, 1min, 2000rm, 10min); the dispersed slurry was uniformly applied to the front end of an aluminum foil, and the coating was started with the dispersion thickness (250 μm) set. After coating, the coating is horizontally placed in a 100 ℃ air drying oven for drying for 2h. Taking the pole pieces out of the oven, cooling to room temperature, shearing a section of the pole piece, punching 4 pole pieces by using a slicing machine, and weighing by using a one-hundred-thousand balance. Selecting an area with uniform thickness to cut 4 pole pieces with the width of 4-5cm, rolling by using a double-roller machine, measuring the thickness of the rolled pole pieces by using a micrometer, wiping the contact positions of the pole pieces such as an upper punch, a lower punch, a trough and the like by using absolute ethyl alcohol-wetted dust-free paper before using a sheet punching machine, punching 8-10 pole pieces from each sample by using the sheet punching machine after wiping, observing whether the edges of the pole pieces are smooth and have no powder falling or not, and enabling the diameter of the punched pieces to be 14mm.
2. And (5) drying in vacuum. And putting the weighed pole pieces into a vacuum oven, pressing, and drying for more than 4 hours at 105 ℃ under the vacuum degree of-90 KPa.
3. Preparing before assembly, and confirming the specification of the auxiliary assembly materials. Battery case: CR2430; electrolyte solution: FB097; thickness of foamed nickel: 2.3mm; diameter of the diaphragm: 22mm; lithium sheet: 0.5mm thick and 18mm diameter. Confirming the environmental conditions of the glove box: water content < 0.01ppm; the oxygen content is less than 0.01ppm.
4. And grinding the lithium sheet. And (3) polishing the convex surface of the lithium sheet to be smooth by using a wool brush, and placing the polished lithium sheet on a clean paper towel.
5. And (6) assembling. And placing a negative electrode shell on the dust-free paper. The nickel foam was then placed with the nickel foam flat down and convex side up. And then placing the lithium sheet in the center of the foamed nickel with the right side facing upwards. And then dropping a drop of electrolyte, placing a diaphragm, then dropping 1 drop of electrolyte, placing a pole piece, placing the positive electrode shell with the aluminum foil surface of the pole piece facing upwards. And putting the assembled battery into a sealing machine by using insulating tweezers to seal the battery at the sealing pressure of 500kg for 5 s. The surface of the button lithium ion battery is carefully wiped by using dust-free paper, the negative electrode of the battery faces upwards, and the battery is clamped on a battery clamp in sequence.
6. Starting after selecting a corresponding test method on the blue light test software, and inputting the corresponding active substance mass.
The button lithium ion batteries manufactured respectively have numbers of A1-A6, which correspond to the lithium iron phosphate positive electrode materials manufactured in the embodiments 1-6. Numbers B1 to B4 are respectively corresponding to the lithium iron phosphate anode materials prepared in comparative examples 1 to 4.
(2) Battery performance testing
The button lithium ion batteries A1-A6 and B1-B4 prepared above are respectively placed on a test cabinet, and the current system is firstly tested in a constant temperature box at 25 ℃ with 0.1C as above: standing for 3h; charging at 0.1C rate until the voltage is more than or equal to 3.75V; charging at 3.75V to a current of less than or equal to 0.05mA at a constant voltage; standing for 5min; discharging at 0.1C rate until the voltage is less than or equal to 2V. Recording the first discharge capacity of the battery, and calculating the mass specific capacity of the battery according to the following formula.
Specific capacity = first discharge capacity (mAh) of battery/weight of positive electrode material (g)
The performance data of the finished battery and the compaction density of the lithium iron phosphate cathode material obtained by the test are shown in table 1.
From the data in the table, it can be analyzed that the lithium iron phosphate positive electrode material with high compaction density prepared by the method of the present invention is used as a positive electrode active material, the initial discharge mass specific capacity of the batteries (A1-A6) prepared by preparing the positive electrode sheet and further assembling the positive electrode sheet is obviously higher than that of the reference batteries (B1-B4) of the comparative example, and the compaction density of the lithium iron phosphate positive electrode material prepared by the method of the present invention is obviously higher than that of the comparative example, so the lithium iron phosphate positive electrode material prepared by the method of the present invention has higher compaction density, and the button battery prepared by the method of the present invention has higher discharge capacity of 0.1C.
Claims (10)
1. The preparation method of the high-compaction lithium iron phosphate cathode material is characterized by comprising the following steps of:
(1) Selecting large-particle uncrushed iron phosphate, wherein the particle size of the iron phosphate is 20-25 mu m, and if the total mass of the raw material of the lithium iron phosphate positive electrode material is 100%, the content of the large-particle uncrushed iron phosphate accounts for 100%;
(2) Uniformly mixing the iron phosphate with a lithium source, a carbon source and a solvent, grinding, and spray-drying to obtain a lithium iron phosphate precursor, wherein the grinding is carried out until the median particle diameter D50 is less than 0.5 mu m, and the rotating speed of an atomizing wheel of a spray drying tower is 18000rmp-19500rmp in the spray drying process;
(3) And roasting, crushing, screening and demagnetizing the lithium iron phosphate precursor in a protective atmosphere to obtain the high-compaction lithium iron phosphate anode material.
2. The method according to claim 1, wherein in the step (2), the spray particle size is controlled to 15 to 25 μm by adjusting the rotation speed of the atomizing wheel of the spray drying tower.
3. The method according to claim 1, wherein in the step (2), the lithium source comprises any one of lithium carbonate, lithium hydroxide, lithium nitrate, lithium oxalate or lithium acetate or a combination of at least two thereof.
4. The method according to claim 1, wherein in the step (2), the lithium source and the iron phosphate are mixed in a ratio of elemental lithium: the molar ratio of the iron element is (0.95-1.05): 1.
5. The method according to claim 1, wherein in the step (2), the carbon source is one or a mixed carbon source of two or more of glucose, sucrose and polyethylene glycol, and when the carbon source is a mixed carbon source, the carbon source is a mixture of glucose and polyethylene glycol in a mass ratio of 1:2 or mixing the sucrose and the polyethylene glycol according to a mass ratio of 1:1 or mixing sucrose, glucose and polyethylene glycol according to a mass ratio of 1:1:2 mixed carbon source.
6. The preparation method according to claim 1, wherein in the step (2), the carbon source is added in an amount of 10% to 15% by mass based on the mass of the lithium iron phosphate precursor.
7. The method of claim 1, wherein in step (2), the grinding is performed until a median particle size of 0.35 μm < D50 < 0.5 μm.
8. The preparation method according to claim 1, wherein in the step (3), the heating rate of the roasting is 2-20 ℃/min, the temperature of the roasting is 720-780 ℃, and the time of the roasting is 6-15 h.
9. The lithium iron phosphate cathode material is characterized by being prepared by the method of any one of claims 1 to 8, and the powder compaction density of the lithium iron phosphate cathode material is more than 2.55g/cm 3 。
10. A lithium ion battery, characterized in that, by applying the lithium iron phosphate cathode material of claim 9, the 0.1C discharge of the lithium ion battery is between 158 and 163 mAh/g.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211239708.3A CN115974031A (en) | 2022-10-11 | 2022-10-11 | High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211239708.3A CN115974031A (en) | 2022-10-11 | 2022-10-11 | High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115974031A true CN115974031A (en) | 2023-04-18 |
Family
ID=85957068
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211239708.3A Pending CN115974031A (en) | 2022-10-11 | 2022-10-11 | High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115974031A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102612487A (en) * | 2009-09-09 | 2012-07-25 | 户田工业株式会社 | Ferric phosphate hydrate particle powder and process for production thereof, olivine-type lithium iron phosphate particle powder and process for production thereof, and non-aqueous electrolyte secondary battery |
| CN107814372A (en) * | 2017-11-02 | 2018-03-20 | 沈阳国科金能新材料有限公司 | A kind of preparation method and application of lithium iron phosphate positive material |
| CN112599767A (en) * | 2020-12-18 | 2021-04-02 | 湖北融通高科先进材料有限公司 | Preparation method of lithium iron phosphate material |
-
2022
- 2022-10-11 CN CN202211239708.3A patent/CN115974031A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102612487A (en) * | 2009-09-09 | 2012-07-25 | 户田工业株式会社 | Ferric phosphate hydrate particle powder and process for production thereof, olivine-type lithium iron phosphate particle powder and process for production thereof, and non-aqueous electrolyte secondary battery |
| CN107814372A (en) * | 2017-11-02 | 2018-03-20 | 沈阳国科金能新材料有限公司 | A kind of preparation method and application of lithium iron phosphate positive material |
| CN112599767A (en) * | 2020-12-18 | 2021-04-02 | 湖北融通高科先进材料有限公司 | Preparation method of lithium iron phosphate material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2023534756A (en) | Lithium ion battery positive electrode lithium replenishment additive and its preparation method and lithium ion battery | |
| CN109742489B (en) | Lithium-oxygen/air battery and preparation method thereof | |
| CN111403693A (en) | Negative active material, and negative electrode sheet, electrochemical device, and electronic device using same | |
| CN111769267A (en) | Composite positive electrode material of lithium ion battery and preparation method thereof | |
| CN116613306B (en) | Layered oxide positive electrode material, preparation method thereof, positive electrode composition, sodium ion secondary battery and application | |
| CN110600680A (en) | Positive electrode slurry, positive plate comprising positive electrode slurry and lithium ion battery | |
| CN114079086A (en) | Positive electrode lithium supplement additive, positive electrode plate, preparation method of positive electrode plate and lithium ion battery | |
| CN108565409B (en) | Lithium iron phosphate composite material and preparation method thereof | |
| CN114512660B (en) | Positive active material precursor, preparation method thereof and positive active material | |
| CN102544511A (en) | Lithium ion battery positive electrode lithium ferrous phosphate material wrapped with strontium cerium doped cobaltate (SCC) and carbon, and preparation method for lithium ion battery positive electrode lithium ferrous phosphate material | |
| CN111082017A (en) | Composite positive electrode material of sodium ion secondary battery, preparation method of composite positive electrode material and battery | |
| CN116646488A (en) | Pre-lithiated hard carbon composite material, preparation method and application thereof | |
| CN110444734A (en) | Silicon sulphur battery prelithiation method | |
| CN102403511A (en) | Lithium ion battery cathode material lanthanum strontium cobalt oxide and carbon coated lithium iron phosphate and preparation method thereof | |
| CN116014069A (en) | Pre-lithiated composite negative electrode plate, preparation method thereof and lithium ion battery | |
| CN115974031A (en) | High-compaction lithium iron phosphate positive electrode material, preparation method thereof and lithium ion battery | |
| CN114695851B (en) | Composite anode material, anode, battery and preparation method thereof | |
| CN114122380A (en) | Preparation method of zirconium-doped cerium fluoride-coated nickel-cobalt-manganese ternary positive electrode material and prepared positive electrode material | |
| CN109962232B (en) | Positive electrode active material, preparation method, positive electrode and battery | |
| CN113328096A (en) | Preparation method of silicon-carbon composite material, silicon-based negative electrode material and lithium ion battery | |
| CN117276531B (en) | Doped layered oxide positive electrode material, method for producing same, positive electrode composition, sodium ion secondary battery, and use | |
| CN112624205B (en) | Fe2(SO4)3Preparation method and application of negative electrode material | |
| CN114497465B (en) | Preparation method of pole piece, electrochemical device and electronic device | |
| CN115028169B (en) | Preparation method of porous silicon monoxide negative electrode material for lithium ion battery | |
| CN114684850B (en) | Zinc-based pre-lithiated material and preparation method and application thereof |
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 |