CN110745802A - Method for preparing lithium iron phosphate by electromagnetic induction self-heating - Google Patents
Method for preparing lithium iron phosphate by electromagnetic induction self-heating Download PDFInfo
- Publication number
- CN110745802A CN110745802A CN201910971177.9A CN201910971177A CN110745802A CN 110745802 A CN110745802 A CN 110745802A CN 201910971177 A CN201910971177 A CN 201910971177A CN 110745802 A CN110745802 A CN 110745802A
- Authority
- CN
- China
- Prior art keywords
- iron phosphate
- lithium iron
- lithium
- electromagnetic induction
- heating
- 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
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D1/00—Evaporating
- B01D1/16—Evaporating by spraying
- B01D1/18—Evaporating by spraying to obtain dry solids
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/37—Phosphates of heavy metals
- C01B25/375—Phosphates of heavy metals of iron
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B25/00—Phosphorus; Compounds thereof
- C01B25/16—Oxyacids of phosphorus; Salts thereof
- C01B25/26—Phosphates
- C01B25/45—Phosphates containing plural metal, or metal and ammonium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- 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
-
- 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
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
Abstract
The invention provides a method for preparing lithium iron phosphate by electromagnetic induction self-heating, aiming at solving the problems of high sintering cost, low synthesis efficiency, low capacity, poor conductivity and the like in the existing lithium iron phosphate preparation technology. Adding a magnetic iron source, a magnetic phosphorus source, a magnetic lithium source and a magnetic carbon source into deionized water, mixing, stirring, ball-milling, spray-drying, placing a spray precursor into an induction furnace, self-heating and preserving heat for a period of time under the atmosphere of inert gas, and naturally cooling to room temperature to obtain the lithium iron phosphate. The method has the advantages of low energy consumption, high heating rate, high heating efficiency and uniform material heating; the final product has no impurity phase, uniform appearance, high specific capacity, good conductivity and excellent cycle performance; easy availability of raw materials, simple process, low cost, easy industrial production and the like.
Description
Technical Field
The invention relates to the field of lithium batteries, in particular to a method for preparing a positive material lithium iron phosphate, and especially relates to a method for preparing lithium iron phosphate by electromagnetic induction self-heating.
Technical Field
Lithium ion batteries have been developed rapidly in recent years, and lithium iron phosphate, which is one of the main positive electrode materials of lithium ion batteries, has the advantages of high capacity, low cost, good safety, good thermal stability, greenness, no pollution and the like, and is widely applied to energy storage, aerospace, automobile power batteries and other aspects. However, the existing industrialized lithium iron phosphate production process is mainly a high-temperature solid-phase synthesis method, wherein most of the sintering processes adopt roller bed furnace sintering, which has the disadvantages of low heating efficiency, slow temperature rise, uneven material heating and the like, resulting in high sintering cost, low synthesis efficiency, non-uniform final product, impurity phase existence, low capacity and poor conductivity, and limits the application of lithium iron phosphate materials to a certain extent.
Disclosure of Invention
At present, most lithium iron phosphate materials on the market have the defects of impure materials, uneven appearance, lower specific capacity, poor conductivity and the like.
In order to realize the purpose of the invention, the technical scheme is as follows:
s1, preparing lithium iron phosphate slurry: sequentially adding a lithium source and a phosphorus source into deionized water, and uniformly stirring and mixing to obtain a lithium-phosphorus mixed solution; and adding a magnetic iron source and a carbon source into the mixed solution, wherein the ratio of lithium: iron: phosphorus: the molar ratio is (1.0-1.1): 1:1, adding 1-10% of carbon source by mass of finished lithium iron phosphate, and then mixing, stirring and sanding for 6-8 h.
And S2, preparing a lithium iron phosphate precursor, namely drying and granulating the lithium iron phosphate slurry prepared in the S1 by using a centrifugal spray drying tower to obtain the lithium iron phosphate precursor.
S2, preparation of lithium iron phosphate: and (4) putting the lithium iron phosphate precursor obtained in the step (S2) into a high-temperature refractory container, then putting the container into an electromagnetic induction furnace, self-heating to 730-780 ℃ at a speed of 10-15 ℃/min in an inert gas atmosphere, preserving the temperature for 6-8h, naturally cooling, and finally performing jet milling to obtain a lithium iron phosphate finished product.
Further, the lithium source in S1 is one or more of lithium carbonate, lithium hydroxide monohydrate, lithium oxalate, lithium acetate, and lithium dihydrogen phosphate; the phosphorus source is one or more of ammonium dihydrogen phosphate, phosphoric acid and lithium dihydrogen phosphate; the magnetic iron source is one of iron powder and ferroferric oxide; the carbon source is one or more of glucose monohydrate, sucrose, polyethylene glycol, graphene and carbon nano tubes; the stirring frequency is 50-100 rpm; the ball milling medium of the sand mill is zirconia balls with the diameter of 0.3-0.4mm, and the rotating speed is 1200-2000 r/min.
Furthermore, the inlet temperature and the outlet temperature of the spray drying in S2 are respectively 150-220 ℃ and 70-100 ℃, and the rotating speed of the atomizing disc is 18000-21000 r/min.
Further, the current of the induction cooker in the S3 is 220V alternating current; the inert gas is helium, argon or nitrogen; the air pressure of 1.0-1.2 MPa is adopted in the jet milling, and the D50 granularity is controlled to be 0.5-1 micron.
The existing industrialized lithium iron phosphate production process is mainly a high-temperature solid-phase synthesis method, wherein most of sintering procedures adopt roller furnace sintering, and the sintering process has the defects of low heating efficiency, slow temperature rise, nonuniform material heating and the like, so that the process has the disadvantages of high sintering cost, low synthesis efficiency, non-uniform final finished product, impurity phase existence, low capacity and poor conductivity. In view of this, the invention provides a method for preparing lithium iron phosphate by electromagnetic induction. The technical idea of the invention is as follows: adding a magnetic iron source, a magnetic phosphorus source, a magnetic lithium source and a magnetic carbon source into deionized water, mixing, stirring, ball-milling, spray-drying, placing a spray precursor into an induction furnace, self-heating and preserving heat for a period of time under the atmosphere of inert gas, and naturally cooling to room temperature to obtain lithium iron phosphate; the electromagnetic induction heating is that the temperature of an iron source with magnetism in a precursor rises through the electromagnetic induction effect, and then the precursor is heated by the heat released by the iron source; compared with the traditional heating mode, the heating mode heats the precursor by the temperature rise of the iron source inside the heating mode, the iron source is uniformly distributed in the precursor, so that the precursor is heated uniformly, and crystals grow uniformly without impurity phases in the lithium iron phosphate synthesis process. Compared with the existing preparation method of lithium iron phosphate, the method has the following advantages:
1. the sintering process adopts an electromagnetic induction self-heating mode, and has the advantages of low energy consumption, high heating rate, high heating efficiency and uniform material heating.
2. The lithium iron phosphate material obtained by the method is heated uniformly in the synthesis process, and the final product has no impurity phase, uniform appearance, high specific capacity, good conductivity and excellent cycle performance.
3. The scheme of the invention has the advantages of no impurity introduction, no doping, easy obtainment of raw materials, simple process, low cost and easy industrialized production.
Description of the drawings:
FIG. 1 is a diagram of an electromagnetic induction self-heating device according to the present invention
FIG. 2 is a scanning electron micrograph of example 1 of the present invention
FIG. 3 is a scanning electron micrograph of example 2 of the present invention
FIG. 4 is a scanning electron micrograph of example 3 of the present invention
FIG. 5 is a scanning electron micrograph of example 4 of the present invention
FIG. 6 is a scanning electron micrograph of example 5 of the present invention
FIG. 7 is a comparative XRD pattern of examples 1 and 6 of the present invention
FIG. 8 is an XRD contrast pattern of example 2 and example 7 of the present invention
FIG. 9 is an XRD contrast pattern of examples 3 and 8 of the present invention
FIG. 10 is an XRD contrast pattern of examples 4 and 9 of the present invention
FIG. 11 is an XRD contrast pattern of examples 5 and 10 of the present invention
FIG. 12 is a graph comparing the specific capacities of example 1 and example 6 of the present invention
FIG. 13 is a graph comparing the specific capacities of example 2 and example 7 of the present invention
FIG. 14 is a graph comparing the specific capacities of example 3 and example 8 of the present invention
FIG. 15 is a graph comparing the specific capacities of example 4 and example 9 of the present invention
FIG. 16 is a graph comparing the specific capacities of example 5 and example 10 of the present invention
Detailed Description
Example 1:
5L of deionized water, 388g of lithium carbonate, 1150g of ammonium dihydrogen phosphate and 558.5g of iron powder (the molar ratio of lithium to iron to phosphorus in the raw materials is 1.05:1:1) and 100g of dextrose monohydrate are added into a reaction tank in sequence, each substance is added and stirred for 0.5h, then the next substance is added, all the substances are stirred and sanded for 6h after the addition, and the uniformly mixed lithium iron phosphate slurry S1 is obtained, wherein the stirring frequency is 100 revolutions per minute, the ball milling medium of a sand mill is zirconia balls with the diameter of 0.3-0.4mm, and the rotating speed is 2000 revolutions per minute.
And (3) carrying out centrifugal spray drying on S1, wherein the inlet temperature and the outlet temperature are 220 ℃ and 100 ℃, and the rotating speed of an atomizing disc is 21000 r/min, so as to obtain a lithium iron phosphate precursor S2.
And S2 is placed into a high-temperature refractory container, the container is placed into an electromagnetic induction furnace, the container is self-heated to 780 ℃ at a speed of 10 ℃/min under the atmosphere of high-purity nitrogen, the container is kept warm for 6 hours and then is naturally cooled, finally, a jet mill is used for crushing, and the air pressure of 1.0MPa is adopted for jet crushing, so that the lithium iron phosphate is obtained. The lithium iron phosphate prepared in the example has no impurity, uniform spherical particles, 0.58 mu m of D50, 1.52% of carbon content, 159mAh/g of 1C full-electric discharge gram capacity, 1.1 omega-cm of resistivity and 93% of 1C 1000-cycle retention rate.
Example 2:
5L of deionized water, 416.3g of lithium hydroxide monohydrate, 1150g of ammonium dihydrogen phosphate, 558.5g of iron powder (the molar ratio of lithium to iron to phosphorus in the raw materials is 1.1:1:1) and 280g of sucrose are added into a reaction tank in sequence, each substance is added and stirred for 0.5h, then the next substance is added, all the substances are stirred and sanded for 6h after the addition, and uniformly mixed lithium iron phosphate slurry S1 is obtained, wherein the stirring frequency is 80 revolutions per minute, the ball milling medium of a sand mill is zirconia balls with the diameter of 0.3-0.4mm, and the rotating speed is 1800 revolutions per minute.
And (3) carrying out centrifugal spray drying on S1, wherein the inlet temperature and the outlet temperature are respectively 200 ℃ and 100 ℃, and the rotating speed of an atomizing disc is 20000 revolutions per minute, so as to obtain the precursor S2 of the lithium iron phosphate.
And S2 is placed into a high-temperature refractory container, the container is placed into an electromagnetic induction furnace, the container is self-heated to 780 ℃ at a speed of 10 ℃/min under the atmosphere of high-purity nitrogen, the container is kept warm for 6 hours and then is naturally cooled, finally, a jet mill is used for crushing, and the air pressure of 1.0MPa is adopted for jet crushing, so that the lithium iron phosphate is obtained. The lithium iron phosphate prepared in the example has no impurity, uniform spherical particles, 0.55 mu m of D50, 4.96 percent of carbon content, 157mAh/g of 1C full-electric discharge gram capacity, 1.3 omega-cm of resistivity and 92 percent of 1C 1000-cycle retention rate.
Example 3:
5L of deionized water, 519.7g of lithium oxalate, 1152.6g of 80% phosphoric acid, 558.5g of iron powder (the molar ratio of lithium to iron to phosphorus in the raw materials is 1.02:1:1) and 130g of polyethylene glycol are added into a reaction tank in sequence, each substance is added and stirred for 0.5h, then the next substance is added, all the substances are stirred and sanded for 7h after being added, and uniformly mixed lithium iron phosphate slurry S1 is obtained, wherein the stirring frequency is 80 revolutions per minute, the ball milling medium of a sand mill is 0.3-0.4mm zirconia balls, and the rotating speed is 1600 revolutions per minute.
And (3) carrying out centrifugal spray drying on S1, wherein the inlet temperature and the outlet temperature are respectively 180 ℃ and 90 ℃, and the rotating speed of an atomizing disc is 19000 r/min, so as to obtain a lithium iron phosphate precursor S2.
And S2 is placed into a high-temperature refractory container, the container is placed into an electromagnetic induction furnace, the container is self-heated to 750 ℃ at a speed of 12 ℃/min under the atmosphere of high-purity nitrogen, the container is kept warm for 7 hours and then is naturally cooled, finally, a jet mill is used for crushing, and the air pressure of 1.1MPa is adopted for jet crushing, so that the lithium iron phosphate is obtained. The lithium iron phosphate prepared in the example has no impurity, uniform spherical particles, 0.63 mu m of D50, 2.87% of carbon content, 160mAh/g of 1C full-electric discharge gram capacity, 2.1 omega-cm of resistivity and 93% of 1C 1000-cycle retention rate.
Example 4:
5L of deionized water, 686g of lithium acetate, 1152.6g of 80% phosphoric acid, 771.8g of ferroferric oxide (the molar ratio of lithium to iron to phosphorus in the raw materials is 1.04:1:1) and 240g of graphene are added into a reaction tank in sequence, each substance is added and stirred for 0.5h, then the next substance is added, all the substances are stirred and sanded for 8h after being added, and uniformly mixed lithium iron phosphate slurry S1 is obtained, wherein the stirring frequency is 60 revolutions per minute, the ball-milling medium of a sand mill is 0.3-0.4mm of zirconia balls, and the rotating speed is 1400 revolutions per minute.
And (3) carrying out centrifugal spray drying on S1, wherein the inlet temperature and the outlet temperature are respectively 170 ℃ and 80 ℃, and the rotating speed of an atomizing disc is 18000 r/min, so as to obtain a lithium iron phosphate precursor S2.
And S2 is placed into a high-temperature refractory container, the container is placed into an electromagnetic induction furnace, the container is self-heated to 730 ℃ at a speed of 15 ℃/min under the atmosphere of high-purity nitrogen, the container is kept warm for 8 hours, then the container is naturally cooled, finally a jet mill is used for crushing, and the air pressure of 1.2MPa is adopted for jet crushing, so that the lithium iron phosphate is obtained. The lithium iron phosphate prepared in the example has no impurity, uniform spherical particles, 0.61 mu m of D50, 9.83% of carbon content, 153mAh/g of 1C full electric discharge gram capacity, 1.3 omega cm of resistivity and 89% of 1C1000 cycle retention rate.
Example 5:
5L of deionized water, 1039.1g of lithium dihydrogen phosphate, 771.8g of ferroferric oxide (the molar ratio of lithium to iron to phosphorus in the raw materials is 1:1:1) and 170g of carbon nano tube are added into a reaction tank in sequence, each substance is added, then the next substance is added after being stirred for 0.5h, and after all the substances are added, the mixture is stirred and sanded for 8h to obtain uniformly mixed lithium iron phosphate slurry S1. the stirring frequency is 50 revolutions per minute, the ball milling medium of a sand mill is zirconia balls with the diameter of 0.3-0.4mm, and the rotating speed is 1200 revolutions per minute.
And (3) carrying out centrifugal spray drying on S1, wherein the inlet temperature and the outlet temperature are respectively 150 ℃ and 70 ℃, and the rotating speed of an atomizing disc is 21000 r/min, so as to obtain a lithium iron phosphate precursor S2.
And S2 is placed into a high-temperature refractory container, the container is placed into an electromagnetic induction furnace, the container is self-heated to 730 ℃ at a speed of 15 ℃/min under the atmosphere of high-purity nitrogen, the container is kept warm for 8 hours, then the container is naturally cooled, finally a jet mill is used for crushing, and the air pressure of 1.2MPa is adopted for jet crushing, so that the lithium iron phosphate is obtained. The lithium iron phosphate prepared in the example has no impurity, the particles are uniform and spherical, the D50 is 0.59 mu m, the carbon content is 7.33%, the 1C full-electric discharge gram-capacity is 157mAh/g, the resistivity is 2.0 omega-cm, and the 1C 1000-cycle retention rate is 92%.
Example 6:
this example is a comparative example of example 1, and under the same conditions as in example 1, a resistance furnace was used in the sintering stage instead of an electromagnetic induction furnace, and the heating method was a radiation heat transfer method instead of electromagnetic induction self-heating, to prepare lithium iron phosphate. The lithium iron phosphate prepared in the example has a few minor phases, D50 is 2.3 mu m, the carbon content is 1.37%, the 1C full-electric discharge gram capacity is 138mAh/g, the resistivity is 27 omega cm, and the 1C 1000-cycle retention rate is 86%.
Example 7:
this example is a comparative example of example 2, and under the same conditions as in example 2, a microwave tube furnace was used in the sintering process instead of an electromagnetic induction furnace, and microwave heating was used instead of electromagnetic induction self-heating in the heating manner to prepare lithium iron phosphate. The lithium iron phosphate prepared in the example has a few impurity phases, D50 is 2.6 mu m, the carbon content is 4.77%, the 1C full-electric discharge gram capacity is 136mAh/g, the resistivity is 31 omega cm, and the 1C 1000-cycle retention rate is 84%.
Example 8:
this example is a comparative example of example 3, and under the same conditions as in example 3, a vacuum rotary furnace was used in the sintering stage instead of an electromagnetic induction furnace, and the heating method was radiation heating instead of electromagnetic induction self-heating, to prepare lithium iron phosphate. The lithium iron phosphate prepared in the example has a few minor phases, the D50 is 2.8 mu m, the carbon content is 2.76%, the 1C full-electric discharge gram capacity is 133mAh/g, the resistivity is 34 omega cm, and the 1C1000 cycle retention rate is 81%.
Example 9:
this example is a comparative example of example 4, and under the same conditions as in example 4, an infrared heating furnace was used in the sintering section instead of an electromagnetic induction furnace, and the heating mode was radiation heating instead of electromagnetic induction self-heating, to prepare lithium iron phosphate. The lithium iron phosphate prepared in the example has a few minor phases, the D50 is 2.9 mu m, the carbon content is 9.66%, the 1C full-electric discharge gram capacity is 140mAh/g, the resistivity is 28 omega cm, and the 1C 1000-cycle retention rate is 85%.
Example 10:
this example is a comparative example of example 5, and under the same conditions as in example 5, a resistance furnace was used in the sintering stage instead of an electromagnetic induction furnace, and the heating method was radiation heating instead of electromagnetic induction self-heating, to prepare lithium iron phosphate. The lithium iron phosphate prepared in this example has a slightly-impure phase, D50 of 3.2 μm, a carbon content of 7.11%, a 1C full-electric discharge gram capacity of 139mAh/g, a resistivity of 40 Ω & cm, and a 1C 1000-cycle retention of 85%.
As can be seen from fig. 2 to 6, the lithium iron phosphate synthesized by electromagnetic induction self-heating is uniform and spherical in shape and size; as can be seen from fig. 7-11, the lithium iron phosphate synthesized by electromagnetic induction self-heating is purer and has no impurity phase than the lithium iron phosphate synthesized by other heating methods; as can be seen in fig. 12-16, the gram capacity of discharge in the examples is significantly higher than the comparative examples and the discharge plateau is higher.
Uniformly mixing the lithium iron phosphate prepared in the embodiments 1-10, PVDF, SP and S-0 according to a mass ratio of 96:3:0.5:0.5, then coating the mixture on an aluminum foil with a thickness of 0.018mm, coating the mixture with a thickness of 100-120 microns, fully drying to obtain a positive pole piece, performing rolling, winding and shell filling, performing laser welding sealing, injecting liquid into a glove box filled with nitrogen gas, and finally performing a charge and discharge performance test on a Lanqi cabinet type battery tester with a charge and discharge voltage of 3.65-2.0V.
The following table shows the results of testing lithium iron phosphate prepared in examples 1 to 10:
the detection results show that the process has low sintering energy consumption, and the synthesized lithium iron phosphate has high specific capacity and good cycle performance.
The above examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention. Further, it should be understood that any changes and modifications to the present invention may occur to those skilled in the art after reading the present teachings, and such equivalents are also intended to be limited by the appended claims.
Claims (10)
1. The method for preparing lithium iron phosphate by electromagnetic induction self-heating is characterized by comprising the following steps:
s1, preparing lithium iron phosphate slurry: sequentially adding a lithium source and a phosphorus source into deionized water, and uniformly stirring and mixing to obtain a lithium-phosphorus mixed solution; and adding a magnetic iron source and a carbon source into the mixed solution, wherein the ratio of lithium: iron: phosphorus: the molar ratio is (1.0-1.1): 1:1, adding 1-10% of carbon source by mass of finished lithium iron phosphate, and then mixing, stirring and sanding for 6-8 h;
s2, preparing a lithium iron phosphate precursor, namely drying and granulating the lithium iron phosphate slurry prepared in the step S1 by using a centrifugal spray drying tower to obtain the lithium iron phosphate precursor;
s3, preparation of lithium iron phosphate: and (4) putting the lithium iron phosphate precursor obtained in the step (S2) into a high-temperature refractory container, then putting the container into an electromagnetic induction furnace, self-heating to 730-780 ℃ at a speed of 10-15 ℃/min under an inert gas atmosphere, preserving the temperature for 6-8h, naturally cooling, and finally performing jet milling to obtain a lithium iron phosphate finished product.
2. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 1, wherein the lithium source in step S1 is one or more of lithium carbonate, lithium hydroxide monohydrate, lithium oxalate, lithium acetate, and lithium dihydrogen phosphate.
3. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 1, wherein the phosphorus source in step S1 is one or more of ammonium dihydrogen phosphate, phosphoric acid and lithium dihydrogen phosphate.
4. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 1, wherein the iron source with magnetism in step S1 is one of iron powder and ferroferric oxide.
5. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 1, wherein the carbon source in step S1 is one or more of glucose monohydrate, sucrose, polyethylene glycol, graphene and carbon nanotubes.
6. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 1, wherein in the step S1, the stirring frequency is 50-100 rpm; the ball milling medium of the sand mill is zirconia balls with the diameter of 0.3-0.4mm, and the rotating speed is 1200-2000 r/min.
7. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to any one of claims 1 to 6, wherein the inlet and outlet temperatures of the spray drying in the step S2 are 150-220 ℃ and 70-100 ℃, respectively, and the rotation speed of the atomizing disk is 18000-21000 rpm.
8. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 7, wherein the current of the electromagnetic induction furnace in the step S3 is 220V alternating current; the inert gas is helium, argon or nitrogen; the air pressure of 1.0-1.2 MPa is adopted in the jet milling, and the D50 granularity is controlled to be 0.5-1 micron.
9. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 7, wherein the inlet temperature and the outlet temperature of the spray drying in the step S2 are respectively 180 ℃ and 90 ℃, and the rotating speed of the atomizing disk is 19000 r/min.
10. The method for preparing lithium iron phosphate through electromagnetic induction self-heating according to claim 8, wherein air pressure of 1.1MPa is adopted for air flow pulverization in step S3, and the D50 particle size is controlled to be 0.63 microns.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910971177.9A CN110745802A (en) | 2019-10-14 | 2019-10-14 | Method for preparing lithium iron phosphate by electromagnetic induction self-heating |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910971177.9A CN110745802A (en) | 2019-10-14 | 2019-10-14 | Method for preparing lithium iron phosphate by electromagnetic induction self-heating |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110745802A true CN110745802A (en) | 2020-02-04 |
Family
ID=69278170
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910971177.9A Pending CN110745802A (en) | 2019-10-14 | 2019-10-14 | Method for preparing lithium iron phosphate by electromagnetic induction self-heating |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110745802A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114204023A (en) * | 2021-11-17 | 2022-03-18 | 合肥国轩高科动力能源有限公司 | Preparation method of low-temperature lithium iron phosphate cathode material |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100102270A1 (en) * | 2007-05-28 | 2010-04-29 | Wenwen Jia | Method for Preparing Lithium Iron Phosphate as a Positive Electrode Active Material for a Lithium Ion Secondary Battery |
| CN101891181A (en) * | 2010-08-11 | 2010-11-24 | 河北工业大学 | Preparation method of pure-phase high-crystallinity lithium iron phosphate |
| CN106876705A (en) * | 2017-03-31 | 2017-06-20 | 合肥国轩电池材料有限公司 | A kind of preparation method of fabricated in situ carbon/CNT coated lithium iron phosphate composite |
| CN108448102A (en) * | 2018-04-24 | 2018-08-24 | 方嘉城 | A kind of preparation method of high compacted density high power capacity LiFePO4 |
| CN108706564A (en) * | 2018-04-24 | 2018-10-26 | 江西省金锂科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN109867268A (en) * | 2019-01-31 | 2019-06-11 | 鲍君杰 | A kind of preparation method of high-pressure solid high capacity LiFePO4 |
| CN109921003A (en) * | 2019-04-18 | 2019-06-21 | 王东升 | A kind of preparation method of high-pressure solid LiFePO4 |
| CN110061217A (en) * | 2019-04-25 | 2019-07-26 | 绵阳师范学院 | Magnetic thermal reduction prepares LiFePO4/graphene anode material method |
-
2019
- 2019-10-14 CN CN201910971177.9A patent/CN110745802A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20100102270A1 (en) * | 2007-05-28 | 2010-04-29 | Wenwen Jia | Method for Preparing Lithium Iron Phosphate as a Positive Electrode Active Material for a Lithium Ion Secondary Battery |
| CN101891181A (en) * | 2010-08-11 | 2010-11-24 | 河北工业大学 | Preparation method of pure-phase high-crystallinity lithium iron phosphate |
| CN106876705A (en) * | 2017-03-31 | 2017-06-20 | 合肥国轩电池材料有限公司 | A kind of preparation method of fabricated in situ carbon/CNT coated lithium iron phosphate composite |
| CN108448102A (en) * | 2018-04-24 | 2018-08-24 | 方嘉城 | A kind of preparation method of high compacted density high power capacity LiFePO4 |
| CN108706564A (en) * | 2018-04-24 | 2018-10-26 | 江西省金锂科技股份有限公司 | A kind of preparation method of high-pressure solid lithium ion battery anode material lithium iron phosphate |
| CN109867268A (en) * | 2019-01-31 | 2019-06-11 | 鲍君杰 | A kind of preparation method of high-pressure solid high capacity LiFePO4 |
| CN109921003A (en) * | 2019-04-18 | 2019-06-21 | 王东升 | A kind of preparation method of high-pressure solid LiFePO4 |
| CN110061217A (en) * | 2019-04-25 | 2019-07-26 | 绵阳师范学院 | Magnetic thermal reduction prepares LiFePO4/graphene anode material method |
Non-Patent Citations (1)
| Title |
|---|
| 孟方礼: "基于铁粉还原的LiFePO4/C 合成路径及其电化学性能研究", 《无机材料学报》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114204023A (en) * | 2021-11-17 | 2022-03-18 | 合肥国轩高科动力能源有限公司 | Preparation method of low-temperature lithium iron phosphate cathode material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110255522B (en) | Preparation method of multistage porous lithium iron phosphate | |
| CN107342411B (en) | Preparation method of graphene-silicon-carbon lithium ion battery negative electrode material | |
| CN100551877C (en) | A kind of freeze forming preparation process of ternary lithium ceramic microphere | |
| CN104752718B (en) | A kind of LiMnxFe1‑xPO4Positive electrode active materials and preparation method thereof | |
| CN109607505A (en) | A kind of preparation method for the LiFePO4 improving cryogenic property | |
| CN111422852B (en) | Preparation method of iron vanadium phosphate | |
| CN104009234B (en) | The method of microwave method synthesis of anode material of lithium-ion battery iron manganese phosphate for lithium | |
| CN103214038A (en) | Preparation method for carbon-coated ferroferric oxide-cobaltosic oxide composite negative electrode material | |
| CN106374104A (en) | Method for preparing sodium fluorine vanadium phosphate material in air atmosphere | |
| CN104752692B (en) | A kind of preparation method of ferrous phosphate lithium/carbon composite positive pole | |
| CN106207150A (en) | A kind of atomizing freeze drying prepares the method for lithium cell negative pole material lithium titanate | |
| CN104617292A (en) | Preparation method of high-capacity spherical Li(Ni, Co, Al)O2 cathode material | |
| CN102208624A (en) | Method for preparing carbon-coated LiFePO4 anode material by using low-temperature solid-phase method | |
| CN115403023A (en) | Method for preparing lithium iron manganese phosphate by supercritical hydrothermal method assisted spray drying | |
| CN110745802A (en) | Method for preparing lithium iron phosphate by electromagnetic induction self-heating | |
| CN106745302A (en) | A kind of coralloid zinc ferrite powder of three-dimensional network and preparation method thereof | |
| CN108017054B (en) | Method for preparing mixed expanded graphite from microcrystalline graphite and flake graphite | |
| CN106981653B (en) | Preparation method of nano spinel type nickel-doped lithium manganate material | |
| CN106299301B (en) | A kind of Li with excellent storage lithium performance3VO4The pattern of nano wire mutually regulates and controls method with object | |
| CN104466167A (en) | Method for preparing positive material LiNi1/3Co1/3Mn1/3O2 of lithium ion battery | |
| CN104022284B (en) | There is the preparation method of lithium ion battery anode material lithium iron phosphate of ion, electronics hybrid conductive network configuration | |
| CN111540901A (en) | Method for preparing lithium iron phosphate (LEP) by using lithium iron (III) phosphate | |
| CN111370692A (en) | Preparation method of lithium iron phosphate as positive electrode material of lithium ion battery and precursor thereof | |
| CN114645314B (en) | Preparation method of ternary positive electrode material with single crystal morphology | |
| CN110247036A (en) | A kind of LiFePO based on lithium ion battery4Base composite positive pole and preparation method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200204 |