CN113036141A - Preparation method of lithium iron phosphate anode slurry - Google Patents

Preparation method of lithium iron phosphate anode slurry Download PDF

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CN113036141A
CN113036141A CN202110260884.4A CN202110260884A CN113036141A CN 113036141 A CN113036141 A CN 113036141A CN 202110260884 A CN202110260884 A CN 202110260884A CN 113036141 A CN113036141 A CN 113036141A
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slurry
iron phosphate
lithium iron
preparation
phosphate anode
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娄明
方振辉
何斌
冯晓彤
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Harbin Wanxin Graphite Valley Technology Co ltd
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    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
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    • 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
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • 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
    • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
    • 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

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Abstract

The invention provides a preparation method of lithium iron phosphate anode slurry, which comprises the following steps: (1) mixing the carbon nano tube conductive slurry, the lithium iron phosphate anode material and the solvent, and then sanding; (2) and mixing the slurry obtained after sanding with a solution containing a binder, and dispersing to obtain the lithium iron phosphate anode slurry. In the invention, the carbon nano tube conductive slurry is used as a conductive agent, and the carbon nano tube conductive slurry and LiFePO are4The positive electrode material is subjected to sanding after being premixed, so that the materials can be fully mixed, and the produced LiFePO can4The positive electrode slurry is uniform and stable; meanwhile, the preparation method has the advantages of simple operation, high product stability, easy operation, simple raw materials and low requirement on equipmentAnd the like, is easy to realize industrial production, and has good economic value and application prospect.

Description

Preparation method of lithium iron phosphate anode slurry
Technical Field
The invention belongs to the technical field of battery preparation, and particularly relates to a preparation method of lithium iron phosphate anode slurry.
Background
In recent years, with the further development of lithium ion batteries, especially the wide application of power lithium ion batteries, people have made higher demands on various performances of lithium ion batteries, such as the uniform stability of batteries. Lithium ion batteries have been widely used in the fields of portable electronic devices, electric vehicles, energy storage devices, etc. because of their advantages of high operating voltage, large specific energy, fast charging, long cycle life, etc. The lithium ion battery mainly comprises a positive electrode material, a negative electrode material, a diaphragm and electrolyte. The positive plate is composed of an active substance, a conductive agent, a binder and a current collector. Lithium iron phosphate with an olivine structure becomes a widely used anode material of the current lithium ion battery due to the advantages of high theoretical capacity, low cost, high thermal stability and the like.
The uniformity and stability of the anode slurry directly influence the coating, and the dispersion quality of the anode slurry is particularly important, so that the performance of the anode active material and the conductive agent material of the lithium ion battery is promoted rapidly. At present, the material dispersion effect is poor under the traditional stirring process, and the conductive agent cannot be well filled in the anode material, so that the performance of the lithium ion battery is influenced. If the materials can be fully mixed, the anode active material and the conductive agent particles are uniformly distributed, the conductivity is good, and the prepared anode slurry with uniform dispersion and good processing performance can certainly greatly improve the comprehensive performance of the lithium ion battery.
CN106299269A discloses a preparation method of anode slurry of a lithium ion battery, which comprises the steps of mixing an active substance of an anode material, a conductive agent and an N-methyl pyrrolidone solvent, adding the mixture into a vacuum mixer, quickly stirring at a high temperature in a vacuum environment, then exhausting and condensing, removing part of the N-methyl pyrrolidone solvent in the slurry, finally adding a polyvinylidene fluoride glue solution, and uniformly stirring at a high speed in the vacuum environment by circulating water to obtain the uniformly dispersed anode slurry. The traditional vacuum stirring method is adopted for production in the method, and the dispersion effect is poor.
Therefore, optimizing the production process to produce uniform and stable anode slurry has profound significance for the development of lithium battery production, and is a research focus in the field.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a preparation method of lithium iron phosphate anode slurry. In the lithium iron phosphate anode slurry prepared by the method, all materials are fully mixed, and the anode slurry is uniform and stable as a whole.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a preparation method of a lithium iron phosphate positive electrode slurry, including the following steps:
(1) mixing carbon nanotube conductive slurry and lithium iron phosphate (LiFePO)4) Mixing the positive electrode material and the solvent, and then sanding;
(2) then mixing the slurry obtained after sanding with a solution containing a binder, and dispersing to obtain the LiFePO4A positive electrode slurry.
In the invention, the carbon nano tube conductive slurry is used as a conductive agent, and the carbon nano tube conductive slurry and LiFePO are4The positive electrode material is subjected to sand grinding after being premixed, so that the materials are favorably and fully mixed, and the problem that the carbon nano tube dry powder is easy to agglomerate and difficult to disperse due to direct addition of the carbon nano tube conductive slurry is solved;
meanwhile, the binder is added into the solvent and stirred for a period of time to prepare a solution containing the binder, and then the solution is stirred with other raw materials, so that the problem that the PVDF is difficult to disperse and mix unevenly is solved; therefore, the preparation method provided by the invention can fully mix all the materials, the synthesis operation is simple, and the produced LiFePO is4The positive electrode slurry is uniform and stable.
As a preferable technical solution of the present invention, the mass ratio of the carbon nanotube conductive paste, the lithium iron phosphate positive electrode material and the solvent in the step (1) is (10 to 50): (70 to 120): (40 to 80), and may be, for example, 10:70:40, 10:70:50, 10:70:60, 10:70:80, 10:80:40, 10:90:40, 10:100:40, 10:110:40, 10:120:40, 20:70:40, 30:70:40, 40:70:40, 20:80:50, 30:90:60, 40:100:70, 50:105:60, 50:120:80, or the like.
Preferably, the solid content of the carbon nanotube conductive paste in step (1) is 4-6%, for example, 4%, 4.2%, 4.4%, 4.5%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.5%, 5.6%, 5.7%, 5.8%, or 6%.
Preferably, the solvent of step (1) comprises N-methylpyrrolidone (NMP).
Preferably, the mixing of step (1) is carried out in a premixer.
Preferably, the mixing time in step (1) is 0.5-4 h, for example, 0.5h, 0.8h, 1h, 1.2h, 1.5h, 2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h, 3.8h or 4h, etc.
Preferably, the sanding time in step (1) is 0.5-4 h, such as 0.5h, 0.8h, 1h, 1.2h, 1.5h, 2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h, 3.8h or 4 h.
In a preferred embodiment of the present invention, the mass ratio of the slurry obtained by sanding in step (2) to the binder-containing solution is (8 to 16): (1 to 6), and may be, for example, 8:1, 8:2, 8:3, 8:4, 8:6, 9:1, 10:1, 12:1, 14:1, 16:1, 10:2, 12:3, 14:3, 16:3, 12:2, 12:4, 12:6, 15:2, 16:4, or 16: 6.
Preferably, the binder of step (2) comprises polyvinylidene fluoride (PVDF).
Preferably, the binder-containing solution of step (2) includes an N-methylpyrrolidone solution containing polyvinylidene fluoride.
The common binder of the lithium ion battery is PVDF, and due to good electrochemical stability and binding capacity and good electrolyte absorption capacity, lithium is favorably transferred to the surface of an active substance, so that the PVDF is the most widely applied binder of the lithium ion battery. However, the electrode active material is coated with the semi-crystalline PVDF, the PVDF in the crystalline region inhibits the extraction or insertion of lithium ions, and the active material is unevenly distributed and easily clustered due to the weak interaction between the active material and the PVDF.
In the invention, the binder is added into the solvent and stirred for a period of time to prepare the binder-containing solution, and then the binder-containing solution is stirred with other raw materials, so that the problem that PVDF is difficult to disperse and mix unevenly is solved.
Preferably, the mass concentration of the polyvinylidene fluoride in the binder-containing solution in the step (2) is 5% to 20%, and may be, for example, 5%, 6%, 8%, 10%, 12%, 14%, 15%, 16%, 18%, 20%, or the like.
Preferably, the dispersing time in the step (2) is 0.5-4 h, for example, 0.5h, 0.8h, 1h, 1.2h, 1.5h, 2h, 2.5h, 2.8h, 3h, 3.2h, 3.5h, 3.8h or 4h, etc.
Preferably, the rotation speed of the dispersion in the step (2) is 1000-3000 r/min, such as 1000r/min, 1200r/min, 1400r/min, 1500r/min, 1600r/min, 1800r/min, 2000r/min, 2200r/min, 2400r/min, 2500r/min, 2600r/min, 2800r/min or 3000 r/min.
As a preferred technical scheme of the invention, the preparation method comprises the following steps:
(1) dispersing polyvinylidene fluoride powder into an N-methyl pyrrolidone solution for 0.5-4 h to obtain a polyvinylidene fluoride glue solution, wherein the mass concentration of the polyvinylidene fluoride glue solution is 5-20%;
premixing 10-50 wt% (70-120 wt%) of carbon nanotube conductive slurry, 40-80 wt% of lithium iron phosphate anode material and N-methyl pyrrolidone in a premixer for 0.5-4 h, and sanding the slurry obtained after premixing for 0.5-4 h;
(2) mixing the sand-milled slurry with the mass ratio of (8-16) to (1-6) with polyvinylidene fluoride glue, and dispersing for 0.5-4 h at the speed of 1000-3000 r/min to obtain the lithium iron phosphate anode slurry
In a second aspect, the invention provides a lithium iron phosphate positive electrode slurry prepared by the preparation method in the first aspect.
Preferably, the viscosity of the lithium iron phosphate positive electrode slurry is less than or equal to 10000cp, and can be 500cp, 1000cp, 2000cp, 3000cp, 4000cp, 5000cp, 5500cp, 6000cp, 7000cp, 8000cp, 9000cp or 10000cp, and the like.
Preferably, the solid content of the lithium iron phosphate positive electrode slurry is 40% to 65%, and may be, for example, 40%, 42%, 45%, 46%, 48%, 50%, 52%, 55%, 56%, 58%, 60%, 62%, 65%, or the like.
Preferably, the lithium iron phosphate positive electrode slurry has a sheet resistivity of 30 to 60 Ω · cm, and may be, for example, 30 Ω · cm, 32 Ω · cm, 35 Ω · cm, 38 Ω · cm, 40 Ω · cm, 42 Ω · cm, 45 Ω · cm, 48 Ω · cm, 50 Ω · cm, 52 Ω · cm, 55 Ω · cm, 58 Ω · cm, or 60 Ω · cm.
Preferably, the slurry fineness of the lithium iron phosphate positive electrode slurry is less than or equal to 50 μm, and may be, for example, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, or 50 μm.
In a third aspect, the invention further provides an application of the lithium iron phosphate positive electrode slurry in the second aspect in preparation of a lithium ion battery.
The recitation of numerical ranges herein includes not only the above-recited values, but also any values between any of the above-recited numerical ranges not recited, and for brevity and clarity, is not intended to be exhaustive of the specific values encompassed within the range.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the carbon nano tube conductive slurry is used, so that the problem that the carbon nano tube dry powder is easy to agglomerate and difficult to disperse due to direct addition of the carbon nano tube dry powder is solved, and the dispersion of the slurry is facilitated; meanwhile, the carbon nano tube conductive slurry is mixed with LiFePO4The anode material is premixed and then sanded, so that the materials can be fully mixed, the synthesis operation is simple, and the produced LiFePO is4The positive electrode slurry is uniform and stable;
(2) LiFePO provided by the invention4The preparation method of the anode slurry has the advantages of simple operation, high product stability, easy operation, simple raw materials, low requirement on equipment and the like, is easy to realize industrial production, and has good economic value and application prospect.
Drawings
FIG. 1 shows LiFePO prepared in example 14Electron microscopy of the positive electrode slurry (1 μm ruler).
FIG. 2 shows LiFePO prepared in example 14Electron microscopy of the positive electrode slurry (3 μm scale).
FIG. 3 shows LiFePO prepared in comparative example 14Electron microscopy of the positive electrode slurry (1 μm ruler).
FIG. 4 shows LiFePO prepared in comparative example 14Electron microscopy of the positive electrode slurry (3 μm scale).
Detailed Description
The technical solutions of the present invention are further described in the following embodiments with reference to the drawings, but the following examples are only simple examples of the present invention and do not represent or limit the scope of the present invention, which is defined by the claims.
In the following examples, unless otherwise specified, reagents and consumables were purchased from conventional reagent manufacturers in the field; unless otherwise indicated, all experimental methods and technical means used are those conventional in the art.
Example 1
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) dispersing PVDF powder into an NMP solution for 0.5h to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 5%;
(2) mixing carbon nano tube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 10:82:454Premixing the anode material and NMP in a premixer for 0.5h, and sanding the premixed slurry for 0.5 h;
(3) mixing the sand milled slurry with the mass ratio of 9:1 and a PVDF glue solution at 3000r/min, and dispersing for 0.5h to obtain uniformly dispersed LiFePO4A positive electrode slurry.
Example 2
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) dispersing PVDF powder into an NMP solution for 1h to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 8%;
(2) mixing carbon nano tube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 20:96:674Premixing the anode material and NMP in a premixer for 1h, and sanding the premixed slurry for 1 h;
(3) mixing the sand-milled slurry and the PVDF glue solution in a mass ratio of 10:3, and dispersing for 1h at 2500r/min to obtain uniformly dispersed LiFePO4A positive electrode slurry.
Example 3
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) dispersing PVDF powder into an NMP solution for 2 hours to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 10%;
(2) mixing carbon nano tube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 30:101:694Premixing the anode material and NMP in a premixer for 2h, and sanding the premixed slurry for 2 h;
(3) mixing the sand milled slurry with the PVDF glue solution in a mass ratio of 12:5 for 1000r/min, and dispersing for 2h to obtain uniformly dispersed LiFePO4A positive electrode slurry.
Example 4
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) dispersing PVDF powder into an NMP solution for 3 hours to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 15%;
(2) mixing carbon nanotube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 42:115:734Premixing the anode material and NMP in a premixer for 3h, and sanding the premixed slurry for 3 h;
(3) mixing the sand milled slurry with the mass ratio of 13:2 and a PVDF glue solution for 1000r/min, and dispersing for 3h to obtain uniformly dispersed LiFePO4A positive electrode slurry.
Example 5
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) and (3) dispersing the PVDF powder into an NMP solution for 4 hours to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 20%.
(2) Mixing carbon nanotube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 50:117:794Premixing the anode material and NMP in a premixerAnd 4h, sanding the premixed slurry for 4 h.
(3) Mixing the sand milled slurry with the mass ratio of 15:6 and a PVDF glue solution for 1000r/min, and dispersing for 4h to obtain uniformly dispersed LiFePO4A positive electrode slurry.
Example 6
The difference from example 1 is that the carbon nanotube conductive paste (solid content 5%), LiFePO are mixed4The mass ratio of the positive electrode material to NMP was adjusted to 10:82:90, and the remaining steps were kept in accordance with example 1.
Example 7
The difference from example 1 is that the carbon nanotube conductive paste (solid content 5%), LiFePO are mixed4The mass ratio of the positive electrode material to NMP was adjusted to 10:82:30, and the remaining steps were kept the same as in example 1.
Example 8
The difference from example 1 is that the mass ratio of the sanded slurry to the PVDF gum solution was adjusted to 6:1, and the remaining steps were in accordance with example 1.
Example 9
The difference from example 1 is that the mass ratio of the sanded slurry to the PVDF gum solution was adjusted to 20:1, and the remaining steps were in accordance with example 1.
Comparative example 1
The present embodiment provides a LiFePO4The preparation method of the anode slurry comprises the following specific steps:
(1) dispersing PVDF powder into an NMP solution for 0.5h to obtain a PVDF glue solution for later use, wherein the mass concentration of the PVDF glue solution is 5%;
(2) mixing carbon nano tube conductive slurry (solid content is 5%) and LiFePO in a mass ratio of 10:82:454Premixing the anode material and MNP in a premixer for 0.5 h;
(3) mixing the sand milled slurry and the PVDF glue solution in a mass ratio of 9:1, and dispersing at a high speed for 0.5h to obtain uniformly dispersed LiFePO4A positive electrode slurry.
It is different from example 1 in that step (2) is not subjected to sanding treatment.
Comparative example 2
The difference from example 1 is that the carbon nanotube conductive paste is replaced with graphene conductive paste, and the remaining steps are consistent with example 1.
Performance testing
1. Analysis by Electron microscopy
LiFePO prepared in example 14Micrographs of the positive electrode slurry are shown in fig. 1 and 2;
LiFePO prepared in comparative example 14Micrographs of the positive electrode slurry are shown in figures 3 and 4,
it can be seen from the figure that compared to comparative example 1, LiFePO obtained in the preparation method provided by the present invention4The anode slurry has better uniformity, uniform particle size in the conductive slurry and better dispersibility and stability.
2. The invention expresses the dispersibility and consistency of the slurry through the fluctuation range of the viscosity and fineness of the slurry, and the dispersibility and consistency of the slurry are good if the fluctuation range is small;
measuring the viscosity and the fineness of each sample for 20 times, wherein the time interval is 2min, and the fluctuation range of 20 times is observed; the viscosity is measured by a viscometer, and the fineness is measured by a scraper fineness meter;
the specific results are shown in table 1 below:
TABLE 1
Figure BDA0002969924730000091
Figure BDA0002969924730000101
As can be seen from the above table, the LiFePO provided in the embodiments of the present invention4The viscosity fluctuation range and the fineness fluctuation range of the positive electrode slurry are smaller; for example, LiFePO obtained in example 14The viscosity fluctuation range of the positive electrode slurry is 1-6 mPa · s, and the fineness fluctuation range is 0-4 μm;
compared with comparative examples 1 and 2, the slurry has small fluctuation range of viscosity and fineness, which shows that the dispersion and consistency of the slurry are good;
from comparison among examples 1, 6 and 7, the LiFePO was obtained4The positive electrode slurry has higher or lower NMP content, which affects the dispersibility of the positive electrode slurry, particularly, the positive electrode slurry has higher NMP content, the obtained slurry has larger viscosity fluctuation range, and the stability and the dispersibility are reduced;
as can be seen from comparison among examples 1, 8 and 9, too high or too low a mass ratio of the sanded slurry to the PVDF binder solution affects the dispersibility and uniformity of the positive electrode slurry.
In summary, the present invention provides a LiFePO4The preparation method of the anode slurry is simple to operate, has low requirements on equipment, and the obtained product has high stability and is easy to realize industrial production.
The applicant declares that the above description is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and it should be understood by those skilled in the art that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are within the scope and disclosure of the present invention.

Claims (10)

1. The preparation method of the lithium iron phosphate anode slurry is characterized by comprising the following steps of:
(1) mixing the carbon nano tube conductive slurry, the lithium iron phosphate anode material and the solvent, and then sanding;
(2) and mixing the slurry obtained after sanding with a solution containing a binder, and dispersing to obtain the lithium iron phosphate anode slurry.
2. The preparation method according to claim 1, wherein the mass ratio of the carbon nanotube conductive paste, the lithium iron phosphate positive electrode material and the solvent in the step (1) is (10-50): (70-120): (40-80).
3. The preparation method according to claim 1 or 2, wherein the solid content of the carbon nanotube conductive paste in the step (1) is 4-6%;
preferably, the solvent of step (1) comprises N-methylpyrrolidone.
4. The method according to any one of claims 1 to 3, wherein the mixing in step (1) is carried out in a premixer;
preferably, the mixing time in the step (1) is 0.5-4 h;
preferably, the sanding time in the step (1) is 0.5-4 h.
5. The method according to any one of claims 1 to 4, wherein the mass ratio of the slurry obtained after the sanding in the step (2) to the solution containing the binder is (8-16): 1-6.
6. The method according to any one of claims 1 to 5, wherein the binder of step (2) comprises polyvinylidene fluoride;
preferably, the binder-containing solution of step (2) comprises an N-methylpyrrolidone solution containing polyvinylidene fluoride;
preferably, the mass concentration of the polyvinylidene fluoride in the binder-containing solution in the step (2) is 5-20%.
7. The method according to any one of claims 1 to 6, wherein the dispersing time in step (2) is 0.5 to 4 hours;
preferably, the rotation speed of the dispersion in the step (2) is 1000-3000 r/min.
8. The production method according to any one of claims 1 to 7, characterized by comprising the steps of:
(1) dispersing polyvinylidene fluoride powder into an N-methyl pyrrolidone solution for 0.5-4 h to obtain a polyvinylidene fluoride glue solution, wherein the mass concentration of the polyvinylidene fluoride glue solution is 5-20%;
premixing 10-50 wt% (70-120 wt%) of carbon nanotube conductive slurry, 40-80 wt% of lithium iron phosphate anode material and N-methyl pyrrolidone in a premixer for 0.5-4 h, and sanding the slurry obtained after premixing for 0.5-4 h;
(2) mixing the sand-milled slurry with the mass ratio of (8-16) to (1-6) with polyvinylidene fluoride glue, and dispersing for 0.5-4 h at the speed of 1000-3000 r/min to obtain the lithium iron phosphate anode slurry.
9. The lithium iron phosphate positive electrode slurry prepared by the preparation method of any one of claims 1 to 8;
preferably, the viscosity of the lithium iron phosphate anode slurry is less than or equal to 10000 cp;
preferably, the solid content of the lithium iron phosphate anode slurry is 40-65%;
preferably, the resistivity of a pole piece of the lithium iron phosphate anode slurry is 30-60 omega-cm;
preferably, the fineness of the slurry of the lithium iron phosphate anode slurry is less than or equal to 50 mu m.
10. The use of the lithium iron phosphate positive electrode slurry of claim 9 in the preparation of a lithium ion battery.
CN202110260884.4A 2021-03-10 2021-03-10 Preparation method of lithium iron phosphate anode slurry Pending CN113036141A (en)

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* Cited by examiner, † Cited by third party
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CN102356490A (en) * 2009-03-19 2012-02-15 阿克马法国公司 Fluorinated binder composite materials and carbon nanotubes for positive electrodes for lithium batteries
CN103943851A (en) * 2013-12-20 2014-07-23 宁波维科电池股份有限公司 Lithium iron phosphate aqueous anode slurry and preparation method thereof
CN105406070A (en) * 2015-12-18 2016-03-16 山东精工电子科技有限公司 Preparation method of lithium ion battery positive pole size
WO2017222895A1 (en) * 2016-06-23 2017-12-28 Government Of The United States As Represented By The Secretary Of The Air Force Bendable creasable, and printable batteries with enhanced safety and high temperature stability - methods of fabrication, and methods of using the same
CN109360990A (en) * 2018-12-03 2019-02-19 重庆市典盈新材料科技有限公司 A kind of LiFePO4 battery core positive conductive agent slurry and preparation method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102356490A (en) * 2009-03-19 2012-02-15 阿克马法国公司 Fluorinated binder composite materials and carbon nanotubes for positive electrodes for lithium batteries
CN103943851A (en) * 2013-12-20 2014-07-23 宁波维科电池股份有限公司 Lithium iron phosphate aqueous anode slurry and preparation method thereof
CN105406070A (en) * 2015-12-18 2016-03-16 山东精工电子科技有限公司 Preparation method of lithium ion battery positive pole size
WO2017222895A1 (en) * 2016-06-23 2017-12-28 Government Of The United States As Represented By The Secretary Of The Air Force Bendable creasable, and printable batteries with enhanced safety and high temperature stability - methods of fabrication, and methods of using the same
CN109360990A (en) * 2018-12-03 2019-02-19 重庆市典盈新材料科技有限公司 A kind of LiFePO4 battery core positive conductive agent slurry and preparation method thereof

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Application publication date: 20210625