CN113213447A - Preparation method of high-rate lithium iron phosphate cathode material - Google Patents
Preparation method of high-rate lithium iron phosphate cathode material Download PDFInfo
- Publication number
- CN113213447A CN113213447A CN202110419588.4A CN202110419588A CN113213447A CN 113213447 A CN113213447 A CN 113213447A CN 202110419588 A CN202110419588 A CN 202110419588A CN 113213447 A CN113213447 A CN 113213447A
- Authority
- CN
- China
- Prior art keywords
- iron phosphate
- lithium iron
- titanium nitride
- rate
- positive electrode
- 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.)
- Granted
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
- C01B25/45—Phosphates containing plural metal, or metal and ammonium
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
- C01B21/076—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with titanium or zirconium or hafnium
- C01B21/0768—After-treatment, e.g. grinding, purification
-
- 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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
-
- 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
- H01M2004/021—Physical characteristics, e.g. porosity, surface area
-
- 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
- H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
- H01M2004/028—Positive electrodes
-
- 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)
- Engineering & Computer Science (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Nanotechnology (AREA)
- Physics & Mathematics (AREA)
- Composite Materials (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The invention discloses a preparation method of a high-rate lithium iron phosphate positive electrode material, which specifically comprises the following steps: s1 preparing nano lithium iron phosphate primary particles by a hydrothermal method; s2, dispersing the nano lithium iron phosphate primary particles, the titanium nitride nanowires and a carbon source in a solvent to prepare a suspension, and granulating to obtain lithium iron phosphate/titanium nitride nanowire composite secondary particles; s3, calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles in an inert atmosphere to obtain the high-rate lithium iron phosphate anode material. By means of full contact of the titanium nitride nanowires with high electrical conductivity and thermal conductivity with the lithium iron phosphate primary particles, secondary particles with a through three-dimensional electrical conduction/thermal conduction network inside are obtained, rapid transmission of electrons inside materials is promoted, high-rate discharge performance of the battery is improved, heat dissipation inside the battery in a large-current discharge process is accelerated, and electrochemical performance attenuation and safety risks caused by overhigh temperature are relieved.
Description
Technical Field
The invention belongs to the technical field of lithium ion batteries, and relates to a preparation method of a high-rate lithium iron phosphate positive electrode material.
Background
With the release of application markets of hybrid power, intelligent power stations, national defense and military and the like, higher requirements, particularly rate discharge capacity, are put on lithium ion batteries. The lithium ion battery used as an automobile start-stop power supply generally requires a discharge rate of 20C-30C, and even requires a discharge capacity of more than 50C in the military field. This is a pressing need for optimization and innovation of the critical materials and system design inside the battery.
The lithium iron phosphate material has the advantages of safety, cost, cycle life and the like, is a good choice for power batteries and energy storage batteries, but has the defects of low intrinsic conductivity and small ion diffusion coefficient, and meanwhile, the temperature rise of the battery is faster under large discharge rate, and the requirements on internal resistance and heat conduction of the battery are higher. Aiming at the problems, the conventional optimization mode of the lithium iron phosphate anode material is to carry out nanocrystallization and/or carbon coating, and a good effect is obtained. However, with the continuous expansion of the current application field, the lithium iron phosphate material still needs to be improved continuously, and the development of a high-rate lithium iron phosphate material is imperative.
Disclosure of Invention
In order to solve the problems in the prior art, the invention aims to provide a preparation method of a high-rate lithium iron phosphate positive electrode material, which can effectively improve the electric/heat conduction performance of lithium iron phosphate and improve the high-rate discharge performance of the material.
In order to achieve the purpose, the invention provides the following technical scheme: a preparation method of a high-rate lithium iron phosphate positive electrode material specifically comprises the following steps:
s1, preparing nano lithium iron phosphate primary particles by a hydrothermal method;
s2, dispersing the nano lithium iron phosphate primary particles, the titanium nitride nanowires and a carbon source in a solvent, stirring to prepare a suspension, and granulating to obtain lithium iron phosphate/titanium nitride nanowire composite secondary particles;
and S3, calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles in an inert atmosphere to obtain the high-rate lithium iron phosphate anode material.
Further, in step S1, the temperature of the hydrothermal reaction is 150-180 ℃ and the reaction time is 8-12 h.
Further, in step S1, phosphoric acid, ferrous sulfate, and lithium hydroxide are used as a phosphorus source, an iron source, and a lithium source, and a dispersant polyvinylpyrrolidone and a reducing agent ascorbic acid are added, mixed uniformly, subjected to a hydrothermal reaction to obtain a lithium iron phosphate precipitation solution, and subjected to centrifugation, washing, and drying to obtain the nano lithium iron phosphate primary particles.
Further, the molar ratio of the phosphoric acid to the ferrous sulfate to the lithium hydroxide is 1: (0.95-1.05): (2.95-3.05).
Further, in step S2, the titanium nitride nanowire is prepared by an alkaline thermal reaction between the lithium hydroxide solution and the titanium nitride nanoparticle.
Further, in step S2, the concentration of the lithium hydroxide solution is 8M to 10M, the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide is 1 (1 to 20), the temperature of the alkali-thermal reaction is 120 ℃ to 180 ℃, and the reaction time is 8h to 24 h.
Further, in step S2, the mass ratio of the nano lithium iron phosphate primary particles, the titanium nitride nanowires, and the carbon source is 1: (0.05-0.1): (0.03-0.1).
Further, in step S2, the granulation is performed by spray granulation, wherein the spray inlet temperature is 150 to 200 ℃, and the spray outlet temperature is 75 to 100 ℃.
Further, in step S2, the solvent is one or more of water, ethanol, and isopropanol; the carbon source is one or more of starch, glucose, phenolic resin and asphalt.
Further, in step S3, the calcination temperature is 650 to 800 ℃, and the calcination time is 8 to 15 hours.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention provides a preparation method of a high-rate lithium iron phosphate anode material, which comprises the steps of firstly synthesizing superfine nanoscale lithium iron phosphate primary particles with uniform particle size distribution by a hydrothermal method, and then introducing titanium nitride nanowires in the process of preparing composite secondary particles by a granulation process, wherein the composite secondary particles formed by the nanometer lithium iron phosphate primary particles and the titanium nitride nanowires have higher pore structures, and are beneficial to infiltration of electrolyte on the anode material so as to be beneficial to ion transmission. Meanwhile, the titanium nitride nanowires with high electrical conductivity and thermal conductivity are fully contacted with the lithium iron phosphate primary particles, so that a through three-dimensional electrical/thermal conduction network is formed inside the lithium iron phosphate/titanium nitride nanowire composite secondary particles, rapid transmission of electrons inside the material is promoted, the internal resistance and surface resistance of the material are reduced, and the high-rate discharge performance of the battery is improved. Meanwhile, the heat dissipation in the battery in the heavy-current discharging process is accelerated, the temperature rise of the battery is favorably controlled, and the electrochemical performance attenuation and safety risk caused by overhigh temperature are relieved. The preparation method has the advantages of simple process, stability, controllability, wide raw material source and easy large-scale industrial production.
The invention adopts the following components in percentage by mass as 1: (0.05-0.1) mixing the nano lithium iron phosphate primary particles and the titanium nitride nanowires to prepare the high-rate lithium iron phosphate anode material, wherein under the condition of the mass ratio, the titanium nitride nanowires can be ensured to be dispersed in the nano lithium iron phosphate primary particles, and the capacity of the anode material can not be reduced too much under the condition of improving the rate performance.
The invention adopts spray granulation, which carries out fluidization treatment on the material to be dried through mechanical action, disperses the material into fine particles like fog, and removes most of water at the moment of contacting with hot air, so that the solid matter in the material is dried into spherical particles with regular shapes. The spray granulation is adopted to avoid reunion and sedimentation separation of the nano lithium iron phosphate primary particles, the titanium nitride nanowires and the carbon source, and the original uniformity of the suspension is kept. Meanwhile, the suspension can be uniformly atomized by using spray granulation, the drying speed is high, the surface area of the suspension is greatly increased after atomization, and the obtained product is spherical particles, uniform in particle size distribution and good in fluidity.
Drawings
FIG. 1 is a discharge curve and a temperature rise curve at different magnifications in example 1;
FIG. 2 is a graph showing the discharge curve and the temperature rise curve at different magnifications in comparative example 1.
Detailed Description
The invention is described in further detail below with reference to the figures and the specific examples. It should be noted that the following examples are only for explaining the present invention, and are not intended to limit the present invention.
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: mixing a mixture of 1: (0.95-1.05): (2.95-3.05) taking phosphoric acid, ferrous sulfate and lithium hydroxide as a phosphorus source, an iron source and a lithium source, adding a dispersant polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction for 8-12 h at 150-180 ℃ to obtain a lithium iron phosphate precipitation solution, and centrifuging, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: taking a lithium hydroxide solution with the concentration of 8-10M as a reaction medium, uniformly mixing titanium nitride nanoparticles and lithium hydroxide according to the mass ratio of 1 (1-20), transferring the mixture into a reaction kettle, carrying out alkali thermal reaction at 120-180 ℃ for 8-24 h to obtain a precipitation solution, and carrying out acid washing, water washing, centrifugation and drying to obtain a titanium nitride nanowire;
and step 3: and (3) mixing the nano lithium iron phosphate primary particles prepared in the step (1), the titanium nitride nanowires prepared in the step (2) and a carbon source in a mass ratio of 1: (0.05-0.1): (0.03-0.1) dispersing in a solvent, uniformly stirring to obtain a suspension, spraying and granulating the suspension, wherein the spraying inlet temperature is 150-200 ℃, the outlet temperature is 75-100 ℃, and calcining for 8-15 h at 650-800 ℃ in an inert atmosphere after granulation to ensure that a carbon source firmly coats the surface of the lithium iron phosphate/titanium nitride nanowire composite secondary particles to obtain the high-rate lithium iron phosphate cathode material.
Preferably, the solvent is one or more of water, ethanol, and isopropanol.
Preferably, the carbon source is one or more of starch, glucose, phenolic resin and asphalt.
Example 1
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 0.95: 2.95. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction for 8 hours at 150 ℃ to obtain a lithium iron phosphate precipitation solution, and carrying out centrifugation, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:1 by taking 8M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle, carrying out alkali-thermal reaction for 8 hours at 120 ℃ to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain titanium nitride nanowires;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and starch according to a mass ratio of 1: 0.05: 0.03 is dispersed in water, the suspension is prepared by even stirring, and is granulated by spraying, wherein the spraying inlet temperature is 150 ℃, and the spraying outlet temperature is 75 ℃, so that the lithium iron phosphate/titanium nitride nanowire composite secondary particles are obtained.
And 4, step 4: and (4) calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles prepared in the step (3) for 8 hours at the temperature of 650 ℃ in an inert atmosphere to prepare the final high-rate lithium iron phosphate anode material.
Example 2
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 1: 3. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction at 170 ℃ for 10 hours to obtain a lithium iron phosphate precipitation solution, and carrying out centrifugation, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:5 by taking 9M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle, carrying out an alkali-thermal reaction at 150 ℃ for 20 hours to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain a titanium nitride nanowire;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and phenolic resin according to a mass ratio of 1: 0.1: 0.05 is dispersed in ethanol, evenly stirred to prepare suspension, and the suspension is sprayed and granulated, wherein the spraying inlet temperature is 180 ℃, and the spraying outlet temperature is 80 ℃, so that the lithium iron phosphate/titanium nitride nanowire composite secondary particles are obtained.
And 4, step 4: and (4) calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles prepared in the step (3) at 700 ℃ for 10h in an inert atmosphere to prepare the final high-rate lithium iron phosphate anode material.
Example 3
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 1.05: 3.05. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction at 180 ℃ for 12 hours to obtain a lithium iron phosphate precipitation solution, and carrying out centrifugation, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:20 by taking 10M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle for carrying out an alkali-thermal reaction at 180 ℃ for 24 hours to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain a titanium nitride nanowire;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and asphalt according to a mass ratio of 1: 0.1: 0.1, dispersing in isopropanol, uniformly stirring to obtain a suspension, and performing spray granulation on the suspension, wherein the spray inlet temperature is 200 ℃, and the spray outlet temperature is 100 ℃ to obtain the lithium iron phosphate/titanium nitride nanowire composite secondary particles.
And 4, step 4: and calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles at 800 ℃ for 15h in an inert atmosphere to obtain the final high-rate lithium iron phosphate positive electrode material.
Example 4
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 1: 3. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle for hydrothermal reaction at 160 ℃ for 10 hours to obtain a lithium iron phosphate precipitation solution, and centrifuging, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:10 by taking 9M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle for carrying out an alkaline thermal reaction at 130 ℃ for 22 hours to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain titanium nitride nanowires;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and a carbon source (a mixture of phenolic resin and glucose) according to a mass ratio of 1: 0.5: 0.1, dispersing in a mixed solution of ethanol and water, uniformly stirring to obtain a suspension, and performing spray granulation on the suspension, wherein the spray inlet temperature is 160 ℃ and the spray outlet temperature is 90 ℃ to obtain the lithium iron phosphate/titanium nitride nanowire composite secondary particles.
And 4, step 4: and (4) calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles prepared in the step (3) at the temperature of 750 ℃ for 12h in an inert atmosphere to prepare the final high-rate lithium iron phosphate anode material.
Example 5
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 1.05: 3.05. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction at 180 ℃ for 12 hours to obtain a lithium iron phosphate precipitation solution, and carrying out centrifugation, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:15 by taking 10M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle for carrying out an alkaline thermal reaction for 15 hours at 130 ℃ to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain titanium nitride nanowires;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and a carbon source (a mixture of asphalt, starch and glucose) according to a mass ratio of 1: 0.07: 0.05 is dispersed in a mixture of isopropanol and water, the mixture is evenly stirred to prepare a suspension, and the suspension is sprayed and granulated, wherein the spraying inlet temperature is 200 ℃, and the spraying outlet temperature is 100 ℃, so that the lithium iron phosphate/titanium nitride nanowire composite secondary particles are obtained.
And 4, step 4: and calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles for 15h at 650 ℃ in an inert atmosphere to prepare the final high-rate lithium iron phosphate positive electrode material.
Example 6
A preparation method of a high-rate lithium iron phosphate positive electrode material comprises the following steps:
step 1: phosphoric acid, ferrous sulfate and lithium hydroxide are used as a phosphorus source, an iron source and a lithium source, and the molar ratio is 1: 0.95: 2.95. adding a dispersing agent polyvinylpyrrolidone and a reducing agent ascorbic acid, uniformly mixing, transferring to a reaction kettle, carrying out hydrothermal reaction at 165 ℃ for 10 hours to obtain a lithium iron phosphate precipitation solution, and carrying out centrifugation, washing and drying to obtain nano lithium iron phosphate primary particles;
step 2: adding titanium nitride nanoparticles according to the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide of 1:5 by taking 8M lithium hydroxide solution as a reaction medium, uniformly mixing, transferring the mixture into a reaction kettle, carrying out an alkali-thermal reaction at 170 ℃ for 20 hours to obtain a precipitation solution, and carrying out acid pickling, water washing, centrifugation and drying to obtain titanium nitride nanowires;
and step 3: mixing nano lithium iron phosphate primary particles, titanium nitride nanowires and a carbon source (in a mixture of starch, phenolic resin and glucose) according to a mass ratio of 1: 0.1: 0.07 is dispersed in the mixed solution of water, ethanol and isopropanol, the suspension is prepared by even stirring, the suspension is granulated by spraying, the spraying inlet temperature is 200 ℃, the outlet temperature is 100 ℃, and the lithium iron phosphate/titanium nitride nanowire composite secondary particles are obtained.
And 4, step 4: and (4) calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles prepared in the step (3) for 8 hours at the temperature of 650 ℃ in an inert atmosphere to prepare the final high-rate lithium iron phosphate anode material.
Comparative example 1
Uniformly mixing iron phosphate, lithium carbonate and starch according to a molar ratio of 1:3:0.5, adding ethanol, ball-milling for 1h, introducing nitrogen, pretreating for 5h at 200 ℃, and sintering for 12h at 650 ℃ to obtain the lithium iron phosphate material.
Performance testing
Taking a 5Ah laminated soft package battery as an example, the lithium iron phosphate material prepared in the above example 1 and comparative example 1 is used as the positive electrode, graphite is used as the negative electrode, the negative electrode excess coefficient is 1.08, and the positive electrode slurry (mass ratio): lithium iron phosphate: super P: carbon nanotube: PVDF 95: 2: 1:2, negative electrode slurry (mass ratio): graphite: super P: CMC: SBR 94: 2: 1.5: 2.5, the performance results obtained from the tests are shown in table 1, fig. 1 and fig. 2.
Table 1 shows the capacity retention rate and temperature rise at different rates of example 1 and comparative example 1
Table 1 shows the capacity retention rate and temperature rise at different rates of example 1 and comparative example 1. Fig. 1 is a discharge curve and a temperature rise curve of example 1 at different multiplying factors, fig. 2 is a discharge curve and a temperature rise curve of comparative example 1 at different multiplying factors, and as can be seen from table 1, fig. 1 and fig. 2, comparative example 1 has a capacity retention rate of only 89.6% and a temperature rise of 49.7 ℃ under a 20C high-current discharge condition. In example 1, under the 20C discharge condition, the capacity retention rate can reach 97.1%, and the temperature rise is only 23.9 ℃. Compared with the comparative example 1, the capacity retention rate of the example 1 is improved by 7.5%, and the temperature rise is reduced by 25.8 ℃. It is demonstrated that the method for preparing the lithium iron phosphate positive electrode material used in example 1 has an obvious effect on capacity retention and temperature rise improvement of the battery under high-rate discharge.
The embodiments described above are preferred modes of the present invention. It should be noted that appropriate variations and modifications of the above-described embodiments can be made by those skilled in the art in light of the above disclosure and teachings without departing from the principles of the present invention. Such variations and modifications are intended to fall within the scope of the present invention.
Claims (10)
1. A preparation method of a high-rate lithium iron phosphate positive electrode material is characterized by comprising the following steps:
s1, preparing nano lithium iron phosphate primary particles by a hydrothermal method;
s2, dispersing the nano lithium iron phosphate primary particles, the titanium nitride nanowires and a carbon source in a solvent to prepare a suspension, and granulating to obtain lithium iron phosphate/titanium nitride nanowire composite secondary particles;
and S3, calcining the lithium iron phosphate/titanium nitride nanowire composite secondary particles in an inert atmosphere to obtain the high-rate lithium iron phosphate anode material.
2. The method for preparing a high-rate lithium iron phosphate cathode material according to claim 1, wherein in step S1, the hydrothermal reaction temperature is 150 ℃ to 180 ℃ and the reaction time is 8h to 12 h.
3. The method for preparing a high-rate lithium iron phosphate positive electrode material according to claim 1, wherein in step S1, phosphoric acid, ferrous sulfate, and lithium hydroxide are used as a phosphorus source, an iron source, and a lithium source, a dispersant polyvinylpyrrolidone and a reducing agent ascorbic acid are added, the mixture is uniformly mixed, a hydrothermal reaction is performed to obtain a lithium iron phosphate precipitation solution, and the lithium iron phosphate precipitation solution is centrifuged, washed, and dried to obtain the primary nano lithium iron phosphate particles.
4. The preparation method of the high-rate lithium iron phosphate positive electrode material according to claim 3, wherein the molar ratio of the phosphoric acid to the ferrous sulfate to the lithium hydroxide is 1: (0.95-1.05): (2.95-3.05).
5. The method for preparing a high-rate lithium iron phosphate cathode material as claimed in claim 1, wherein in step S2, the titanium nitride nanowires are prepared from lithium hydroxide solution and titanium nitride nanoparticles by an alkaline thermal reaction.
6. The preparation method of the high-rate lithium iron phosphate positive electrode material according to claim 5, wherein in step S2, the concentration of the lithium hydroxide solution is 8M to 10M, the mass ratio of the titanium nitride nanoparticles to the lithium hydroxide is 1 (1-20), the temperature of the alkaline thermal reaction is 120 ℃ to 180 ℃, and the reaction time is 8h to 24 h.
7. The method for preparing a high-rate lithium iron phosphate positive electrode material as claimed in claim 1, wherein in step S2, the mass ratio of the nano lithium iron phosphate primary particles, the titanium nitride nanowires and the carbon source is 1: (0.05-0.1): (0.03-0.1).
8. The method for preparing a high-rate lithium iron phosphate positive electrode material according to claim 1, wherein in step S2, spray granulation is adopted for the granulation, and the spray inlet temperature is 150 ℃ to 200 ℃ and the outlet temperature is 75 ℃ to 100 ℃.
9. The method for preparing a high-rate lithium iron phosphate positive electrode material according to claim 1, wherein in step S2, the solvent is one or more of water, ethanol, and isopropanol; the carbon source is one or more of starch, glucose, phenolic resin and asphalt.
10. The method for preparing a high-rate lithium iron phosphate positive electrode material according to claim 1, wherein in step S3, the calcination temperature is 650-800 ℃ and the calcination time is 8-15 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110419588.4A CN113213447B (en) | 2021-04-19 | 2021-04-19 | Preparation method of high-rate lithium iron phosphate positive electrode material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110419588.4A CN113213447B (en) | 2021-04-19 | 2021-04-19 | Preparation method of high-rate lithium iron phosphate positive electrode material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113213447A true CN113213447A (en) | 2021-08-06 |
| CN113213447B CN113213447B (en) | 2023-08-22 |
Family
ID=77087757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110419588.4A Active CN113213447B (en) | 2021-04-19 | 2021-04-19 | Preparation method of high-rate lithium iron phosphate positive electrode material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113213447B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117613408A (en) * | 2024-01-19 | 2024-02-27 | 杭州巴特瑞新能源科技有限公司 | Preparation method of lithium iron phosphate single battery applied to outdoor mobile power supply |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103123968A (en) * | 2013-01-29 | 2013-05-29 | 中国科学院过程工程研究所 | High-performance lithium iron phosphate cathode material and preparation method of lithium iron phosphate cathode material |
| CN103594686A (en) * | 2013-11-08 | 2014-02-19 | 浙江南都电源动力股份有限公司 | Production method of high-magnification long service life lithium ion battery anode material TiN phase doped LiFePO4 |
| US20140197130A1 (en) * | 2013-01-11 | 2014-07-17 | Infineon Technologies Ag | Method for manufacturing a plurality of nanowires |
| CN107381519A (en) * | 2017-08-28 | 2017-11-24 | 郭珺 | A kind of preparation method of titanium nitride nano line |
| CN110510594A (en) * | 2019-09-11 | 2019-11-29 | 广州方中化工有限公司 | A kind of method that hydro-thermal method prepares LiFePO 4 material |
| CN110783554A (en) * | 2019-11-27 | 2020-02-11 | 江苏红东科技有限公司 | High-magnification low-temperature-resistant long-life lithium ion battery negative electrode material |
-
2021
- 2021-04-19 CN CN202110419588.4A patent/CN113213447B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20140197130A1 (en) * | 2013-01-11 | 2014-07-17 | Infineon Technologies Ag | Method for manufacturing a plurality of nanowires |
| CN103123968A (en) * | 2013-01-29 | 2013-05-29 | 中国科学院过程工程研究所 | High-performance lithium iron phosphate cathode material and preparation method of lithium iron phosphate cathode material |
| CN103594686A (en) * | 2013-11-08 | 2014-02-19 | 浙江南都电源动力股份有限公司 | Production method of high-magnification long service life lithium ion battery anode material TiN phase doped LiFePO4 |
| CN107381519A (en) * | 2017-08-28 | 2017-11-24 | 郭珺 | A kind of preparation method of titanium nitride nano line |
| CN110510594A (en) * | 2019-09-11 | 2019-11-29 | 广州方中化工有限公司 | A kind of method that hydro-thermal method prepares LiFePO 4 material |
| CN110783554A (en) * | 2019-11-27 | 2020-02-11 | 江苏红东科技有限公司 | High-magnification low-temperature-resistant long-life lithium ion battery negative electrode material |
Non-Patent Citations (1)
| Title |
|---|
| YIBING XIE等: "Preparation of carbon-coated lithium iron phosphate/titanium nitride for a lithium-ion supercapacitor" * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117613408A (en) * | 2024-01-19 | 2024-02-27 | 杭州巴特瑞新能源科技有限公司 | Preparation method of lithium iron phosphate single battery applied to outdoor mobile power supply |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113213447B (en) | 2023-08-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109616638B (en) | Spherical core-shell structure mixed graphite @ hard carbon composite material and preparation method and application thereof | |
| CN107464938B (en) | Molybdenum carbide/carbon composite material with core-shell structure, preparation method thereof and application thereof in lithium air battery | |
| CN109616640B (en) | Modified microcrystalline graphite, preparation thereof and application thereof in lithium ion battery | |
| CN111082031A (en) | Preparation method of lithium phosphate coated high-nickel ternary cathode material | |
| CN102185147A (en) | Nano iron phosphate hollow sphere/graphene composite material and preparation method thereof | |
| CN114335469A (en) | Lithium ion battery anode material and preparation method thereof | |
| CN115101738A (en) | Carbon-coated iron-vanadium bimetallic sodium pyrophosphate phosphate composite material and preparation method and application thereof | |
| CN110931725B (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN110790248B (en) | Iron-doped cobalt phosphide microsphere electrode material with flower-shaped structure and preparation method and application thereof | |
| CN113213447B (en) | Preparation method of high-rate lithium iron phosphate positive electrode material | |
| CN113321198A (en) | Binary metal phosphate anode material and preparation method and application thereof | |
| CN112520719A (en) | Polyimide modified carbon-silicon negative electrode material and preparation method thereof | |
| CN115626637B (en) | Preparation method of carbon/graphene/lithium titanate composite anode material | |
| CN111777051A (en) | Preparation method of sheet lithium iron phosphate electrode material | |
| CN116799210A (en) | Composite lithium supplementing material and preparation method thereof, lithium supplementing coating and preparation method thereof, and lithium battery | |
| CN116666589A (en) | Nano silicon carbon composite negative electrode material with core-shell structure, and preparation method and application thereof | |
| CN115159527B (en) | Hard carbon coated silicon nanoparticle composite microsphere negative electrode material and preparation method and application thereof | |
| CN116332154A (en) | Preparation method of porous silicon-carbon anode material | |
| CN113173567B (en) | Preparation method of hollow spherical iron-based metal phosphide | |
| CN112331842B (en) | Molybdenum dioxide nanoparticle/carbon assembled zigzag nano hollow sphere material and preparation and application thereof | |
| CN111261866B (en) | Preparation method of ZnO/C nano composite microsphere material with capsule structure | |
| CN113735180A (en) | Method for preparing sodium-ion battery anode material by using cobalt-iron sulfide obtained from LDH-based precursor | |
| CN102263248A (en) | Method for preparing carbon coated nanometer LiFePO4 | |
| CN115636404B (en) | Preparation method of spherical coal-based sodium-electricity negative electrode material based on secondary granulation process | |
| CN114512651B (en) | In-situ carbon coating method for lithium titanium silicate particles and composite product |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |