CN112133907A - Lithium ion battery cobalt-free slurry and preparation method and application thereof - Google Patents

Lithium ion battery cobalt-free slurry and preparation method and application thereof Download PDF

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Publication number
CN112133907A
CN112133907A CN202011065925.6A CN202011065925A CN112133907A CN 112133907 A CN112133907 A CN 112133907A CN 202011065925 A CN202011065925 A CN 202011065925A CN 112133907 A CN112133907 A CN 112133907A
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cobalt
free
stirring
ion battery
lithium ion
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李宗达
苏夏
杨树涛
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Svolt Energy Technology Co Ltd
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Svolt Energy 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
    • H01M4/505—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/50—Mixing liquids with solids
    • B01F23/51—Methods thereof
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/50—Mixing liquids with solids
    • B01F23/53—Mixing liquids with solids using driven stirrers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
    • B01F23/50—Mixing liquids with solids
    • B01F23/59—Mixing systems, i.e. flow charts or diagrams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
    • B01F33/00—Other mixers; Mixing plants; Combinations of mixers
    • B01F33/80—Mixing plants; Combinations of mixers
    • B01F33/82—Combinations of dissimilar mixers
    • 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
    • H01M4/04—Processes of manufacture in general
    • 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
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
    • H01M4/525—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
    • H01M4/624—Electric conductive fillers
    • H01M4/625—Carbon or graphite
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

The invention relates to a lithium ion battery cobalt-free slurry and a preparation method and application thereof, wherein the lithium ion battery cobalt-free slurry is composed of cobalt-free material powder, conductive agent powder, a first binder, a second binder and a solvent; the preparation method directly mixes the cobalt-free powder material, the conductive agent powder, the first binder, the second binder and the solvent, so that the cobalt-free material powder can be fully dispersed in a slurry system, the preparation time is short, the preparation efficiency of the cobalt-free slurry of the lithium ion battery is greatly improved, the production efficiency of the cobalt-free slurry of the lithium ion battery is improved, and the production cost is reduced.

Description

Lithium ion battery cobalt-free slurry and preparation method and application thereof
Technical Field
The invention belongs to the technical field of battery materials, relates to a cobalt-free material and a preparation method and application thereof, and particularly relates to a lithium ion battery cobalt-free slurry and a preparation method and application thereof.
Background
Along with the exhaustion of traditional energy and the increasingly outstanding environmental problem, lithium ion battery receives more and more attention as the development direction of novel clean energy, compares with traditional battery, and lithium ion battery has energy density height, long cycle life, open circuit voltage height, no memory effect, advantage such as safe pollution-free.
The lithium ion battery is widely applied to the technical fields of notebook computers, mobile phones, digital cameras, energy storage and the like, the environmental pollution and the global warming caused by automobile exhaust have attracted extensive attention along with the enhancement of the environmental protection consciousness of people, and the research, development and industrialization of energy-saving and environment-friendly electric automobiles become the worldwide attention problem in order to radically cure the environmental pollution and the global warming caused by the automobile exhaust and relieve the energy crisis caused by the increasingly reduced oil resources. Compared with other mobile devices, the electric vehicle has higher requirements on the performances of the battery, such as the cycle life, the consistency of the battery, the large-current discharge capacity and the like.
Homogenate is an important step in the lithium battery manufacturing in the lithium battery industry, and the quality of slurry determines the quality of later coating and final battery performance. The existing methods for homogenizing the anode slurry of the lithium ion battery comprise a wet method and a dry method. The solvent and the binder are stirred by a wet method, then the conductive agent is added for stirring, then the active substance is added for stirring, and the anode slurry is prepared, but the preparation time of the wet method is very long, the production efficiency is seriously influenced, the solid content of the slurry is low, the stability of the slurry is easy to cause poor, and the slurry is easy to generate a layering phenomenon after being placed for a period of time; the dry method is to put the binder, the conductive agent and the active substance into a homogenizing mixer to be dry-mixed and stirred, and then add the solvent to be stirred to prepare the anode slurry, but after the solvent is added by the traditional dry method, the conductive agent is not easy to dissolve, so that the slurry is difficult to disperse, and the uniformity of the slurry is influenced.
CN 111430708A discloses a lithium ion battery anode slurry, and a preparation method and application thereof, wherein the preparation method comprises: (1) mixing a positive electrode active material, a binder, a first conductive agent, and a solvent to obtain a mixed slurry; (2) mixing the mixed slurry with a second conductive agent to obtain the lithium ion battery anode slurry, wherein the first conductive agent is composed of carbon nanotubes, graphene, conductive carbon black, a dispersant and a solvent, and the second conductive agent is conductive carbon black; the positive active substance is a nickel-cobalt-manganese ternary material. The preparation method can obviously improve the distribution of the conductive agent in the positive plate, solves the problem of poor electronic conductivity and ionic transmission of the positive plate, enables the positive electrode to exert higher gram capacity, and has higher rate performance, low-temperature performance and cycle performance.
However, cobalt has a limited global reserve and is expensive. In the existing ternary system lithium ion power battery, the positive proportion of the positive material is about 30-45%, wherein cobalt is the main cost source, and cobalt does not participate in electrochemical reaction, so that the method is a good method for improving the energy density and reducing the cost of the battery by improving the nickel content and reducing the solid content; the cobalt-free battery can improve the electrical property, prolong the service life and safety of the battery, and get rid of the dependence of the anode material on cobalt. However, the cobalt-free battery is prepared by the conventional homogenization method, so that the conductive agent cannot be effectively dispersed.
CN 111584861a discloses a cobalt-free system, a positive electrode slurry, a homogenization method and applications thereof, wherein the cobalt-free system comprises a cobalt-free material, a binder, a conductive agent and a pH regulator, and the homogenization method comprises the following steps: (1) adding the binder, the first conductive agent and the pH regulator into the glue solution, and mixing to obtain a conductive glue A; (2) adding a second conductive agent in a cobalt-free system into the conductive adhesive A obtained in the step (1) and mixing to obtain a conductive adhesive B; (3) and (3) adding a cobalt-free material in a cobalt-free system into the conductive adhesive B obtained in the step (2) and mixing to obtain the anode slurry. The homogenizing method can realize the homogenizing treatment of a cobalt-free system, but has longer treatment time and needs a separate glue making step, so that the production efficiency of the anode slurry is lower.
Therefore, it is required to provide a preparation method of cobalt-free slurry with short homogenization time and high production efficiency, so as to improve the production efficiency of cobalt-free slurry of lithium ion batteries.
Disclosure of Invention
The invention aims to provide a lithium ion battery cobalt-free slurry and a preparation method and application thereof, wherein the preparation method of the lithium ion battery cobalt-free slurry can uniformly disperse cobalt-free material powder in a slurry system in a short time, thereby reducing the dispersion time of the lithium ion battery cobalt-free slurry, improving the production efficiency and reducing the production cost of the lithium ion battery cobalt-free slurry.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the invention provides a lithium ion battery cobalt-free slurry, which comprises the following raw materials in parts by weight: 90-110 parts of cobalt-free material powder, 0.5-2 parts of binder, 0.5-2 parts of first conductive agent powder, 1-2 parts of second conductive agent solution and 80-90 parts of solvent.
The cobalt-free material powder in the cobalt-free slurry for the lithium ion battery is 90 to 110 parts by weight, for example, 90 parts, 95 parts, 100 parts, 105 parts or 110 parts by weight, but the invention is not limited to the recited values, and other values not recited in the numerical range are also applicable.
The weight part of the binder in the cobalt-free slurry of the lithium ion battery is 0.5-2 parts, for example, 0.5 part, 0.8 part, 1 part, 1.2 parts, 1.5 parts, 1.6 parts, 1.8 parts or 2 parts, but is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
The weight part of the first conductive agent powder in the cobalt-free slurry for the lithium ion battery is 0.5-2 parts, for example, 0.5 part, 0.8 part, 1 part, 1.2 parts, 1.5 parts, 1.6 parts, 1.8 parts or 2 parts, but the invention is not limited to the recited values, and other values in the numerical range are also applicable.
The weight part of the second conductive agent solution in the cobalt-free slurry of the lithium ion battery is 1-2 parts, for example, 1 part, 1.2 parts, 1.5 parts, 1.8 parts or 2 parts, but is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
According to the invention, the function of point contact ion conduction can be realized by adding the first conductive agent powder, the function of line contact or surface contact ion conduction can be realized by adding the second conductive agent solution, and the obtained cobalt-free slurry of the lithium ion battery has excellent conductivity by matching the first conductive agent powder and the second conductive agent solution.
The weight portion of the solvent in the cobalt-free slurry of the lithium ion battery is 80-90 parts, for example, 80 parts, 82 parts, 85 parts, 86 parts, 88 parts or 90 parts, but the invention is not limited to the recited values, and other values in the range of the values are also applicable.
Preferably, the cobalt-free material powder is lithium nickel manganese oxide powder.
The lithium nickel manganese oxide powder is a conventional cobalt-free binary powder material in the field, and because cobalt element is not added into the cobalt-free material powder, the appearance and characteristics of the cobalt-free powder material are different from those of a cobalt-containing ternary powder material.
Preferably, the cobalt-free material powder has an average particle size of 3 to 8 μm, for example, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm or 8 μm, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.
Preferably, the binder is a powder binder.
The split binder comprises polyvinylidene fluoride with the number average molecular weight of 50-150 ten thousand.
Preferably, the powder binder has an average particle size of 80 to 120 μm, for example, 80 μm, 90 μm, 100 μm, 110 μm or 120 μm, but is not limited to the values recited, and other values not recited in the range of values are also applicable.
Preferably, the first conductive agent powder is conductive carbon black.
Preferably, the conductive carbon black has an average particle size of 30 to 50nm, and may be, for example, 30nm, 35nm, 40nm, 45nm or 50nm, but is not limited to the recited values, and other values not recited within the range of values are also applicable.
Preferably, the solvent is N-methylpyrrolidone.
Preferably, the second conductive agent solution is composed of conductive carbon black, carbon nanotubes, graphene and N-methylpyrrolidone.
Preferably, the mass fraction of the conductive carbon black in the second conductive agent solution is 40-60%, for example, 40%, 42%, 44%, 46%, 48%, 50%, 52%, 54%, 56%, 58% or 60%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the mass fraction of carbon nanotubes in the second conductive agent solution is 20-40%, for example, 20%, 22%, 24%, 26%, 28%, 30%, 32%, 34%, 36%, 38%, or 40%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the mass fraction of graphene in the second conductive agent solution is 10-30%, for example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
In a second aspect, the present invention provides a method for preparing a cobalt-free material for a lithium ion battery according to the first aspect, wherein the preparation method comprises the following steps: and mixing the raw materials in a double-planet mixer according to the formula ratio to obtain the cobalt-free slurry of the lithium ion battery.
Preferably, the preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer, and premixing and stirring;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material;
(3) and adding the residual solvent into the kneaded material, and stirring and dispersing under a vacuum condition to obtain the cobalt-free slurry of the lithium ion battery.
According to the invention, the first cobalt-free material powder layer, the first conductive agent powder layer, the binder layer and the second cobalt-free material powder layer are firstly paved, and the cobalt-free material powder can be fully mixed with the conductive agent powder and the first binder during premixing and stirring through a specific paving structure, so that the premixing and stirring time is reduced, and the dispersing effect of the cobalt-free material powder in the lithium ion battery cobalt-free slurry obtained by subsequent preparation and the conductive effect of the lithium ion battery cobalt-free slurry are ensured.
Preferably, the cobalt-free material powder in the first cobalt-free material powder layer in step (1) is 40-60% of the total mass of the cobalt-free material powder, for example, 40%, 45%, 50%, 55% or 60%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the cobalt-free material powder in the second cobalt-free material powder layer in step (1) is 40-60% of the total mass of the cobalt-free material powder, for example, 40%, 45%, 50%, 55% or 60%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
The sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder.
Preferably, the revolution speed of the premixed stirring in the step (1) is 20-40r/min, such as 20r/min, 25r/min, 30r/min, 35r/min or 40r/min, but not limited to the enumerated values, and other unrecited values in the numerical range are also applicable; the rotation speed is 400-600r/min, such as 400r/min, 450r/min, 500r/min, 550r/min or 600r/min, but not limited to the values listed, and other values not listed in the numerical range are also applicable.
Preferably, the time for the premixing and stirring in step (1) is 15-25min, such as 15min, 18min, 20min, 24min or 25min, but is not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the portion of the solvent in step (2) is 45-55% of the total amount of the solvent, for example, 45%, 48%, 50%, 52%, 54% or 55%, but not limited to the recited values, and other values not recited in the range of values are also applicable.
Preferably, the stirring and kneading in the step (2) is to stir for 4-6min at a revolution speed of 10-15r/min and then stir for 90-120min at a revolution speed of 20-30 r/min.
In the present invention, the stirring kneading is first carried out at a revolution speed of 10 to 15r/min, for example, 10r/min, 11r/min, 12r/min, 13r/min, 14r/min or 15r/min, but not limited to the enumerated values, and other values not enumerated within the numerical range are also applicable; the stirring time is from 4 to 6min, and may be, for example, 4min, 4.5min, 5min, 5.5min or 6min, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.
Then the process is carried out under the condition of revolution speed of 20-30r/min, such as 20r/min, 22r/min, 25r/min, 27r/min, 28r/min or 30r/min, but not limited to the enumerated values, and other unrecited values in the numerical range are also applicable; the stirring time is 90-120min, for example 90min, 95min, 100min, 105min, 110min, 115min or 120min, but is not limited to the values listed, and other values not listed in the range of values are equally applicable.
Preferably, the vacuum condition in the step (3) is that the relative vacuum degree is less than or equal to-85 KPa.
Preferably, the step of stirring and dispersing in the step (3) comprises: firstly, stirring for 4-6min under the conditions of revolution speed of 15-30r/min and rotation speed of 800-; then stirring for 50-70min under the conditions of revolution speed of 10-35r/min and rotation speed of 3000-4000 r/min.
In the invention, stirring dispersion is firstly carried out for 4-6min under the conditions that the revolution speed is 15-30r/min and the rotation speed is 800-1200r/min, the revolution speed can be 15r/min, 18r/min, 20r/min, 22r/min, 25r/min, 27r/min, 28r/min or 30r/min, the rotation speed can be 800r/min, 900r/min, 1000r/min, 1100r/min or 1200r/min, and the time can be 4min, 4.5min, 5min, 5.5min or 6min, but the invention is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
Stirring and dispersing are carried out for 50-70min under the conditions that the revolution speed is 10-35r/min and the rotation speed is 3000-4000r/min, the revolution speed can be 10r/min, 15r/min, 20r/min, 25r/min, 30r/min or 35r/min, the rotation speed can be 3000r/min, 3200r/min, 3500r/min, 3600r/min or 4000r/min, and the time can be 50min, 55min, 60min, 65min or 70min, but the method is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
Preferably, the preparation method further comprises the step of adjusting the viscosity of the lithium ion battery cobalt-free slurry obtained in the step (3): and (4) mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the step (3), uniformly stirring, and then stabilizing the slurry under a vacuum pumping condition to obtain the lithium ion battery cobalt-free slurry with the viscosity of 4000-7000 cp.
The viscosity of the lithium ion battery cobalt-free slurry after viscosity adjustment is 4000-7000cp, for example, 4000cp, 4500cp, 5000cp, 5500cp, 6000cp, 6500cp or 7000cp, but is not limited to the values listed, and can be reasonably selected by those skilled in the art according to the needs.
Preferably, the viscosity modifying solvent is N-methylpyrrolidone.
Preferably, the uniform stirring is carried out for 15-25min under the conditions of revolution speed of 20-30r/min and rotation speed of 2800-3200 r/min; wherein the revolution speed can be 20r/min, 22r/min, 24r/min, 25r/min, 27r/min, 28r/min or 30r/min, the rotation speed can be 2800r/min, 2900r/min, 3000r/min, 3100r/min or 3200r/min, the time can be 15min, 16min, 18min, 20min, 21min, 24min or 25min, but the method is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
Preferably, the vacuumizing condition is that the relative vacuum degree is less than or equal to-85 KPa;
preferably, the stable slurry is reversely rotated for 8-12min under the condition that the revolution speed is 10-18 r/min; wherein, the revolution speed can be 10r/min, 11r/min, 12r/min, 13r/min, 14r/min, 15r/min, 16r/min, 17r/min or 18r/min, the reverse rotation time can be 8min, 9min, 10min, 11min or 12min, but is not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
As a preferable technical scheme of the preparation method, the preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet mixer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 40-60% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 15-25min under the conditions that the revolution rotating speed is 20-40r/min and the rotation rotating speed is 400-600 r/min;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring and kneading are firstly carried out for 4-6min at the revolution speed of 10-15r/min and then are carried out for 90-120min at the revolution speed of 20-30 r/min; the part of the solvent accounts for 45-55% of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition that the relative vacuum degree is less than or equal to-85 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 4-6min under the conditions of 10-30r/min revolution speed and 800-1200r/min rotation speed; then stirring for 50-70min under the conditions of revolution speed of 10-35r/min and rotation speed of 3000-;
(4) mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the step (3), uniformly stirring, and then stabilizing the slurry under the condition that the relative vacuum degree is less than or equal to-85 KPa to obtain the lithium ion battery cobalt-free slurry with the viscosity of 4000-7000 cp; the uniform stirring is carried out for 15-25min under the conditions of revolution speed of 20-30r/min and rotation speed of 2800-3200 r/min; the stable slurry is reversely rotated for 8-12min under the condition that the revolution rotating speed is 10-18 r/min.
In a third aspect, the invention is embodied in the use of a lithium ion battery cobalt-free slurry as described in the first aspect for a lithium ion battery.
Compared with the prior art, the invention has the following beneficial effects:
(1) the conductive components in the cobalt-free slurry of the lithium ion battery are uniformly dispersed, so that the cobalt-free slurry of the lithium ion battery has excellent electrochemical performance;
(2) the preparation method provided by the invention is simple to operate, can uniformly disperse the conductive components in the first conductive agent powder and the second conductive agent solution in the lithium ion battery cobalt-free slurry, is short in time consumption, overcomes the defect that a step of separately preparing glue is needed in the prior art, and greatly improves the preparation efficiency of the lithium ion battery cobalt-free slurry.
Drawings
Fig. 1 is an SEM image of the coated electrode sheet of the cobalt-free slurry for the lithium ion battery provided in example 1;
FIG. 2 is an EDS diagram of a pole piece coated with the cobalt-free slurry for the lithium ion battery provided in example 1;
FIG. 3 is an SEM image of the pole piece after coating of the cobalt-free slurry for lithium ion battery provided in comparative example 1;
fig. 4 is an EDS diagram of the coated pole piece of the cobalt-free slurry for a lithium ion battery provided in comparative example 1.
Detailed Description
The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, which comprises the following raw materials in parts by weight: 96.1 parts of cobalt-free material powder, 1.2 parts of binder, 1.2 parts of first conductive agent powder, 1.5 parts of second conductive agent solution and 85 parts of solvent.
The cobalt-free material powder is lithium nickel manganese oxide powder with the average particle size of 5 mu m; the adhesive is polyvinylidene fluoride with the number average molecular weight of 100 ten thousand and the average grain diameter of 100 mu m; the first conductive agent powder is conductive carbon black with the average particle size of 40 nm; the solvent is N-methyl pyrrolidone; the second conductive agent solution is composed of conductive carbon black, carbon nanotubes, graphene and N-methylpyrrolidone.
The preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 50% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 20min under the conditions that the revolution speed is 30r/min and the rotation speed is 500 r/min; the sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring kneading is to stir for 5min at the revolution speed of 12r/min and then stir for 100min at the revolution speed of 25 r/min; the part of the solvent accounts for 50 percent of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition of relative vacuum degree of-90 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 5min under the conditions of revolution speed of 20r/min and rotation speed of 1000 r/min; then stirring for 60min under the conditions of revolution speed of 20r/min and rotation speed of 3500 r/min.
The SEM image of the lithium ion battery cobalt-free slurry obtained in this example after coating is shown in fig. 1, and it can be seen from fig. 1 that the particle size distribution in the obtained lithium ion battery cobalt-free slurry is uniform, and the particles therein are effectively dispersed. The EDS of the obtained lithium ion battery cobalt-free slurry coated electrode sheet is shown in fig. 2, and it can be seen from fig. 2 that the obtained lithium ion battery cobalt-free slurry has uniform particle size and no large particle agglomerates. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 190 min.
Example 2
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the raw material composition of the preparation method of the cobalt-free slurry for the lithium ion battery is the same as that of the embodiment 1.
The preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 45% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 18min under the conditions that the revolution speed is 25r/min and the rotation speed is 550 r/min; the sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring and kneading are firstly carried out for 6min at the revolution speed of 10r/min and then are carried out for 120min at the revolution speed of 20 r/min; the part of the solvent accounts for 45 percent of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition of relative vacuum degree of-90 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 5min under the conditions of revolution speed of 25r/min and rotation speed of 900 r/min; then stirring for 65min under the conditions of revolution speed of 15r/min and rotation speed of 3800 r/min.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 214 min.
Example 3
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the raw material composition of the preparation method of the cobalt-free slurry for the lithium ion battery is the same as that of the embodiment 1.
The preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 55% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 22min under the conditions that the revolution speed is 35r/min and the rotation speed is 450 r/min; the sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring and kneading are firstly carried out for 4min at the revolution speed of 15r/min and then are carried out for 90min at the revolution speed of 30 r/min; the part of the solvent is 55% of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition of relative vacuum degree of-90 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 5min under the conditions of revolution speed of 25r/min and rotation speed of 1100 r/min; then stirring is carried out for 55min under the conditions of revolution speed of 25r/min and rotation speed of 3200 r/min.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 176 min.
Example 4
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the raw material composition of the preparation method of the cobalt-free slurry for the lithium ion battery is the same as that of the embodiment 1.
The preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 40% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 15min under the conditions that the revolution speed is 20r/min and the rotation speed is 600 r/min; the sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring kneading is to stir for 5min at the revolution speed of 12r/min and then stir for 100min at the revolution speed of 25 r/min; the part of the solvent accounts for 50 percent of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition of relative vacuum degree of-90 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 6min under the conditions of revolution speed of 15r/min and rotation speed of 1200 r/min; then stirring for 50min under the conditions of revolution speed of 10r/min and rotation speed of 4000 r/min.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 176 min.
Example 5
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the raw material composition of the preparation method of the cobalt-free slurry for the lithium ion battery is the same as that of the embodiment 1.
The preparation method comprises the following steps:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 60% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 25min under the conditions that the revolution speed is 40r/min and the rotation speed is 400 r/min; the sum of the mass of the cobalt-free material powder in the first cobalt-free material powder layer and the mass of the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring kneading is to stir for 5min at the revolution speed of 12r/min and then stir for 100min at the revolution speed of 25 r/min; the part of the solvent accounts for 50 percent of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition of relative vacuum degree of-90 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 4min under the conditions of revolution speed of 30r/min and rotation speed of 800 r/min; then stirring for 70min under the conditions of revolution speed of 35r/min and rotation speed of 3000 r/min.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 204 min.
Example 6
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the preparation method is to adjust the viscosity of the cobalt-free slurry for the lithium ion battery prepared in the embodiment 1 to 5000 cp.
The preparation method comprises the following steps: mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the example 1, uniformly stirring, and then stabilizing the slurry under the condition that the relative vacuum degree is-90 KPa to obtain the lithium ion battery cobalt-free slurry with the viscosity of 5000 cp; the uniform stirring is carried out for 20min under the conditions of revolution speed of 25r/min and rotation speed of 3000 r/min; the stable slurry is reversed for 10min under the condition that the revolution speed is 15 r/min.
The lithium ion battery slurry after the viscosity is adjusted has uniform particle size distribution, and the particles in the slurry are effectively dispersed without large particle agglomerates. The lithium ion battery cobalt-free slurry prepared by the preparation method provided by the embodiment has uniform particle distribution, ensures the electrochemical performance of the lithium ion battery cobalt-free slurry, and has the total preparation time of 220min after being combined with the embodiment 1.
Example 7
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the preparation method is to adjust the viscosity of the cobalt-free slurry for the lithium ion battery prepared in the embodiment 1 to 7000 cp.
The preparation method comprises the following steps: mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the example 1, uniformly stirring, and then stabilizing the slurry under the condition that the relative vacuum degree is-90 KPa to obtain the lithium ion battery cobalt-free slurry with the viscosity of 7000 cp; the uniform stirring is carried out for 15min under the conditions of revolution speed of 20r/min and rotation speed of 3200 r/min; the stable slurry is reversed for 12min under the condition that the revolution speed is 18 r/min.
The lithium ion battery slurry after the viscosity is adjusted has uniform particle size distribution, and the particles in the slurry are effectively dispersed without large particle agglomerates. The lithium ion battery cobalt-free slurry prepared by the preparation method provided by the embodiment has uniform particle distribution, ensures the electrochemical performance of the lithium ion battery cobalt-free slurry, and has the total preparation time of only 217min after being combined with the embodiment 1.
Example 8
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, and the preparation method is to adjust the viscosity of the cobalt-free slurry for the lithium ion battery prepared in the embodiment 1 to 4000 cp.
The preparation method comprises the following steps: mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the example 1, uniformly stirring, and then stabilizing the slurry under the condition that the relative vacuum degree is-90 KPa to obtain the lithium ion battery cobalt-free slurry with the viscosity of 4000 cp; the uniform stirring is carried out for 25min under the conditions of revolution speed of 30r/min and rotation speed of 2800 r/min; the stable slurry is reversed for 8min under the condition that the revolution speed is 10 r/min.
The lithium ion battery slurry after the viscosity is adjusted has uniform particle size distribution, and the particles in the slurry are effectively dispersed without large particle agglomerates. The lithium ion battery cobalt-free slurry prepared by the preparation method provided by the embodiment has uniform particle distribution, ensures the electrochemical performance of the lithium ion battery cobalt-free slurry, and has the total preparation time of only 223min after being combined with the embodiment 1.
Example 9
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, which comprises the following raw materials in parts by weight: 90 parts of cobalt-free material powder, 0.5 part of binder, 0.5 part of first conductive agent powder, 2 parts of second conductive agent solution and 90 parts of solvent.
The cobalt-free material powder is lithium nickel manganese oxide powder with the average particle size of 3 mu m; the adhesive is polyvinylidene fluoride with the number average molecular weight of 100 ten thousand and the average particle size of 80 mu m; the first conductive agent powder is conductive carbon black with the average particle size of 30 nm; the solvent is N-methyl pyrrolidone; the second conductive agent solution is composed of conductive carbon black, carbon nanotubes, graphene and N-methylpyrrolidone.
The preparation process conditions were the same as in example 1.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 190 min.
Example 10
The embodiment provides a preparation method of cobalt-free slurry for a lithium ion battery, which comprises the following raw materials in parts by weight: 110 parts of cobalt-free material powder, 2 parts of binder, 2 parts of first conductive agent powder, 1 part of second conductive agent solution and 80 parts of solvent.
The cobalt-free material powder is lithium nickel manganese oxide powder with the average particle size of 8 mu m; the binder is polyvinylidene fluoride with the number average molecular weight of 100 ten thousand and the average grain diameter of 120 mu m; the first conductive agent powder is conductive carbon black with the average particle size of 50 nm; the solvent is N-methyl pyrrolidone; the second conductive agent solution is composed of conductive carbon black, carbon nanotubes, graphene and N-methylpyrrolidone.
The preparation process conditions were the same as in example 1.
The lithium ion battery cobalt-free slurry obtained in the embodiment has uniform particle size distribution, and particles in the slurry are effectively dispersed, so that no large-particle agglomerates appear. Therefore, the particles in the lithium ion battery cobalt-free slurry obtained by the preparation method provided by the embodiment are uniformly distributed, the electrochemical performance of the lithium ion battery cobalt-free slurry is ensured, and the preparation time is only 190 min.
Example 11
This example provides a method for preparing cobalt-free slurry for a lithium ion battery, which is the same as in example 1 except that the cobalt-free material powder in the first cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder.
Since the second cobalt-free material powder layer is not arranged in the embodiment, the time required for premixing and stirring in the step (1) is increased, and the premixing and stirring effect in the embodiment 1 can be obtained only by stirring for at least 40min under the conditions that the revolution speed is 30r/min and the rotation speed is 500 r/min.
Thus, the absence of the second cobalt-free material powder layer increases the preparation time from 190min to at least 210 min.
Example 12
This example provides a method for preparing cobalt-free slurry for a lithium ion battery, which is the same as in example 1 except that the cobalt-free material powder in the second cobalt-free material powder layer is 100% of the total mass of the cobalt-free material powder.
Since the first cobalt-free material powder layer is not arranged in the embodiment, the time required for the premixing and stirring in the step (1) is increased, and the premixing and stirring effect in the embodiment 1 can be obtained only by stirring for at least 45min under the conditions that the revolution speed is 30r/min and the rotation speed is 500 r/min.
Thus, the absence of the second cobalt-free material powder layer increases the preparation time from 190min to at least 215 min.
Example 13
This example provides a method for preparing cobalt-free slurry for lithium ion battery, which is the same as example 1 except that the step (2) is only stirred at 25r/min for 105 min.
In the embodiment, the second conductive agent solution is not mixed at a low revolution speed, so that the prepared cobalt-free slurry of the lithium ion battery has the problem of particle agglomeration, and the electrochemical performance of the cobalt-free slurry of the lithium ion battery is reduced.
Example 14
This example provides a method for preparing cobalt-free slurry for lithium ion battery, which is the same as example 1 except that the step (2) is performed only at 12r/min for 105 min.
In the embodiment, after the second conductive agent solution is added, the revolution speed is low, so that the problem of particle agglomeration exists in the prepared cobalt-free slurry of the lithium ion battery, and the electrochemical performance of the cobalt-free slurry of the lithium ion battery is reduced.
Example 15
The embodiment provides a preparation method of cobalt-free slurry of a lithium ion battery, which is the same as the embodiment 1 except that the step (3) is only stirred for 65min under the conditions of revolution speed of 20r/min and rotation speed of 1000 r/min.
Because the autorotation speed is low during stirring and dispersion, the particle size of the obtained cobalt-free slurry of the lithium ion battery is larger, and the electrochemical performance of the obtained cobalt-free slurry of the lithium ion battery is reduced.
Comparative example 1
In this comparative example, with reference to the method disclosed in example 1 of CN 111584861a, there is provided a method for preparing a cobalt-free slurry for a lithium ion battery, where the raw materials for preparing the cobalt-free slurry for a lithium ion battery include, by weight: 96.1 parts of cobalt-free material powder, 1.2 parts of binder, 1.2 parts of first conductive agent powder, 1.5 parts of second conductive agent solution and 85 parts of solvent.
The cobalt-free material powder is lithium nickel manganese oxide powder with the average particle size of 5 mu m; the adhesive is polyvinylidene fluoride with the number average molecular weight of 100 ten thousand and the average grain diameter of 100 mu m; the first conductive agent powder is conductive carbon black with the average particle size of 40 nm; the solvent is N-methyl pyrrolidone; the second conductive agent solution is composed of conductive carbon black, carbon nanotubes, graphene and N-methylpyrrolidone.
The preparation is completed by using a double-planet stirrer, and the preparation method comprises the following steps:
(a) mixing the mixed solvent with a binder to prepare glue, wherein the glue preparation time is 240min to obtain a glue solution;
(b) adding first conductive agent powder into the glue solution obtained in the step (a), and then stirring for 10min under the conditions that the revolution rotating speed is 15r/min and the rotation rotating speed is 800 r/min;
(c) then adding a second conductive agent solution, and firstly stirring for 10min under the conditions that the revolution speed is 15r/min and the rotation speed is 800 r/min; then stirring for 50min under the conditions that the revolution speed is 15r/min and the rotation speed is 3000 r/min;
(d) adding cobalt-free material powder, and firstly stirring for 15min under the conditions that the revolution speed is 15r/min and the rotation speed is 600 r/min; then stirring for 20min under the conditions that the revolution speed is 20r/min and the rotation speed is 1500 r/min; and finally stirring for 80min under the conditions that the revolution speed is 20r/min and the rotation speed is 3000r/min to obtain the cobalt-free slurry of the lithium ion battery.
The SEM image of the pole piece of the lithium ion battery obtained in the comparative example after being coated with the cobalt-free slurry is shown in FIG. 3, and it can be known from FIG. 3 that the particle size distribution in the obtained cobalt-free slurry of the lithium ion battery is not uniform; the EDS of the obtained lithium ion battery cobalt-free slurry coated electrode sheet is shown in fig. 4, and it can be seen from fig. 4 that large particle agglomerates exist in the obtained lithium ion battery cobalt-free slurry. Therefore, the preparation method provided by the comparative example cannot ensure the particle distribution in the obtained cobalt-free slurry of the lithium ion battery, so that the electrochemical performance of the obtained cobalt-free slurry of the lithium ion battery is reduced, and the preparation time is 415 min.
In conclusion, the conductive components in the cobalt-free slurry for the lithium ion battery provided by the invention are uniformly dispersed, so that the cobalt-free slurry for the lithium ion battery has excellent electrochemical performance; the preparation method provided by the invention is simple to operate, can uniformly disperse the conductive components in the first conductive agent powder and the second conductive agent solution in the lithium ion battery cobalt-free slurry, is short in time consumption, overcomes the defect that a step of separately preparing glue is needed in the prior art, and greatly improves the preparation efficiency of the lithium ion battery cobalt-free slurry.
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 cobalt-free slurry for the lithium ion battery is characterized by comprising the following raw materials in parts by weight:
Figure FDA0002713756490000011
2. the lithium ion battery cobalt-free slurry according to claim 1, wherein the cobalt-free material powder is lithium nickel manganese oxide powder:
preferably, the average grain diameter of the cobalt-free material powder is 3-8 μm;
preferably, the binder is a powder binder;
preferably, the average particle size of the powder binder is 80-120 μm;
preferably, the first conductive agent powder is conductive carbon black;
preferably, the conductive carbon black has an average particle diameter of 30 to 50 nm;
preferably, the solvent is N-methylpyrrolidone.
3. The lithium ion battery cobalt-free slurry of claim 1 or 2, wherein the second conductive agent solution consists of conductive carbon black, carbon nanotubes, graphene and N-methyl pyrrolidone;
preferably, the mass fraction of the conductive carbon black in the second conductive agent solution is 40-60%;
preferably, the mass fraction of the carbon nanotubes in the second conductive agent solution is 20-40%;
preferably, the mass fraction of the graphene in the second conductive agent solution is 10-30%.
4. A method for preparing a cobalt-free material for a lithium ion battery according to any one of claims 1 to 3, wherein the method comprises the following steps: and mixing the raw materials in a double-planet mixer according to the formula ratio to obtain the cobalt-free slurry of the lithium ion battery.
5. The method of claim 4, comprising the steps of:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer, and premixing and stirring;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material;
(3) and adding the residual solvent into the kneaded material, and stirring and dispersing under a vacuum condition to obtain the cobalt-free slurry of the lithium ion battery.
6. The preparation method according to claim 5, wherein the cobalt-free material powder in the first cobalt-free material powder layer in the step (1) is 40-60% of the total mass of the cobalt-free material powder;
preferably, the cobalt-free material powder in the second cobalt-free material powder layer in the step (1) is 40-60% of the total mass of the cobalt-free material powder;
preferably, the revolution speed of the premixing and stirring in the step (1) is 20-40r/min, and the rotation speed is 400-600 r/min;
preferably, the time for premixing and stirring in the step (1) is 15-25 min.
7. The method according to claim 5 or 6, wherein the partial solvent in step (2) is 45-55% of the total amount of the solvent;
preferably, the stirring and kneading in the step (2) is to stir for 4-6min at a revolution speed of 10-15r/min and then stir for 90-120min at a revolution speed of 20-30 r/min;
preferably, the vacuum condition of the step (3) is that the relative vacuum degree is less than or equal to-85 KPa;
preferably, the step of stirring and dispersing in the step (3) comprises: firstly, stirring for 4-6min under the conditions of revolution speed of 15-30r/min and rotation speed of 800-; then stirring for 50-70min under the conditions of revolution speed of 10-35r/min and rotation speed of 3000-4000 r/min.
8. The preparation method according to any one of claims 5 to 7, further comprising the step of adjusting the viscosity of the lithium ion battery cobalt-free slurry obtained in the step (3): mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the step (3), uniformly stirring, and then stabilizing the slurry under a vacuum pumping condition to obtain the lithium ion battery cobalt-free slurry with the viscosity of 4000-7000 cp;
preferably, the viscosity adjusting solvent is N-methyl pyrrolidone;
preferably, the uniform stirring is carried out for 15-25min under the conditions of revolution speed of 20-30r/min and rotation speed of 2800-3200 r/min;
preferably, the vacuumizing condition is that the relative vacuum degree is less than or equal to-85 KPa;
preferably, the stable slurry is reversely rotated for 8-12min under the condition that the revolution rotating speed is 10-18 r/min.
9. The method according to any one of claims 5 to 8, characterized by comprising the steps of:
(1) sequentially spreading a first cobalt-free material powder layer, a first conductive agent powder layer, a binder layer and a second cobalt-free material powder layer in a double-planet stirrer, and premixing and stirring; the cobalt-free material powder in the first cobalt-free material powder layer accounts for 40-60% of the total mass of the cobalt-free material powder; the premixing and stirring are carried out for 15-25min under the conditions that the revolution rotating speed is 20-40r/min and the rotation rotating speed is 400-600 r/min;
(2) adding a second conductive agent solution and a part of solvent into the mixed powder obtained after premixing and stirring, and then stirring and kneading to obtain a kneaded material; the stirring and kneading are firstly carried out for 4-6min at the revolution speed of 10-15r/min and then are carried out for 90-120min at the revolution speed of 20-30 r/min; the part of the solvent accounts for 45-55% of the total amount of the solvent;
(3) adding the residual solvent into the kneaded material, and stirring and dispersing under the condition that the relative vacuum degree is less than or equal to-85 KPa to obtain the cobalt-free slurry of the lithium ion battery;
the step of stirring and dispersing comprises the following steps: firstly, stirring for 4-6min under the conditions of 10-30r/min revolution speed and 800-1200r/min rotation speed; then stirring for 50-70min under the conditions of revolution speed of 10-35r/min and rotation speed of 3000-;
(4) mixing a viscosity adjusting solvent with the lithium ion battery cobalt-free slurry obtained in the step (3), uniformly stirring, and then stabilizing the slurry under the condition that the relative vacuum degree is less than or equal to-85 KPa to obtain the lithium ion battery cobalt-free slurry with the viscosity of 4000-7000 cp; the uniform stirring is carried out for 15-25min under the conditions of revolution speed of 20-30r/min and rotation speed of 2800-3200 r/min; the stable slurry is reversely rotated for 8-12min under the condition that the revolution rotating speed is 10-18 r/min.
10. Use of a cobalt-free slurry for a lithium-ion battery according to any of claims 1 to 3 in a lithium-ion battery.
CN202011065925.6A 2020-09-30 2020-09-30 Lithium ion battery cobalt-free slurry and preparation method and application thereof Pending CN112133907A (en)

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CN114361714A (en) * 2021-12-06 2022-04-15 惠州市旭然新能源有限公司 Coating slurry, preparation method thereof, composite porous diaphragm prepared from coating slurry and lithium ion battery
CN114784267A (en) * 2022-05-31 2022-07-22 广汽埃安新能源汽车有限公司 Positive electrode slurry, preparation method thereof and lithium ion battery
CN115084519A (en) * 2022-06-13 2022-09-20 蜂巢能源科技(无锡)有限公司 Lithium iron phosphate system slurry and preparation method and application thereof
CN115084519B (en) * 2022-06-13 2024-02-09 蜂巢能源科技(无锡)有限公司 Lithium iron phosphate system slurry and preparation method and application thereof

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Application publication date: 20201225