CN108183218B - Graphene-titanium dioxide composite negative electrode slurry for lithium ion battery and preparation method thereof - Google Patents
Graphene-titanium dioxide composite negative electrode slurry for lithium ion battery and preparation method thereof Download PDFInfo
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- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
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Abstract
The invention belongs to the field of lithium batteries, and provides graphene-titanium dioxide composite negative electrode slurry for a lithium ion battery and a preparation method thereof, wherein the negative electrode slurry comprises the following components in parts by weight: 94-96 parts of graphene-titanium dioxide composite aerogel powder, 0-3 parts of a conductive agent, 0-2 parts of a dispersing agent, 1-3 parts of an adhesive, 0-1 part of a thickening agent and 160 parts of water 140-. The negative electrode slurry contains the graphene-titanium dioxide composite aerogel material, the specific surface area is large, the flexibility is high, the negative electrode sheet coated on the surface of the negative electrode sheet is smooth and has weak rough feeling after being cured, so that the diaphragm can be effectively prevented from being pierced, meanwhile, the negative electrode slurry has high adhesion with a negative electrode current collector after being cured, is not easy to fall off, and the service life of a battery can be prolonged.
Description
Technical Field
The invention relates to the field of lithium batteries, in particular to graphene-titanium dioxide composite negative electrode slurry for a lithium ion battery and a preparation method thereof.
Background
With the development of new energy, lithium ion batteries have been developed in various fields. And the anode and cathode materials of the lithium ion battery play a key role in improving the performance of the lithium ion battery. For lithium ion negative electrode materials, carbon materials were used at the earliest, and then silicon, titanium, composite materials, and the like were developed. On the other hand, graphene has a single-layer two-dimensional sheet structure, a large specific surface area, excellent electrical conductivity, thermal conductivity, low resistivity and the like, and is very suitable for being used as a negative electrode material, and the negative electrode sheet of many lithium ion batteries in the prior art is already applied. The graphene or other composite materials of the graphene and other negative electrode materials are used as the negative electrode, so that the internal resistance of the battery can be obviously reduced, and the cycle performance of the battery can be improved.
Although graphene has numerous advantages, through research, the present inventors have found that graphene also has some disadvantages: although graphene has a single-layer two-dimensional sheet structure, in the actual use process, the inter-sheet distance between adjacent graphene layers is gradually reduced, so that the stripping degree of graphene is reduced, the flexibility of graphene is reduced, and the hardness of graphene is increased. When graphene is used as a negative electrode material and coated on the surface of a negative electrode current collector (usually copper foil) for curing, the surface of a negative electrode sheet becomes very rough due to hard graphene and other negative electrode particle materials, and after a lithium ion battery works for a long time, due to long-term extrusion contact and high-temperature influence of a battery diaphragm and the negative electrode sheet, the diaphragm is easily pierced by the negative electrode sheet, and micro short circuit and even diaphragm failure are easily caused.
In general, in order to improve the puncture resistance of the diaphragm in the prior art, a ceramic coating is coated on the surface of the diaphragm, but the ceramic coating causes new problems: due to the arrangement of the ceramic coating, the air permeability of the diaphragm and the wettability of electrolyte are greatly reduced, so that the performance of the battery is influenced.
Patent 201210533334.6 discloses a graphene composite lithium ion battery cathode material and a preparation method thereof, the cathode material comprises a plurality of graphene sheet layers, a hollow nanometer cathode particle layer is arranged between adjacent graphene sheet layers, the hollow nanometer cathode particles are surrounded and spaced one by the graphene sheet layers, and a gap is reserved between the adjacent graphene sheet layers; the hollow nanometer cathode particles consist of a carbon outer layer and a hollow metal cathode material inner layer. The preparation method comprises the following steps: mixing and reacting an organic precursor of silicon dioxide, a cationic surfactant, a tin salt solution and an organic carbon source; adding graphene oxide or graphene dispersion liquid for reaction and drying to obtain an intermediate product; then the primary product is obtained by treatment of the treatment liquid; and carrying out heat treatment on the primary product to obtain a product. The cathode material has the advantages of good conductivity, large electrochemical lithium storage capacity, high energy density and good cycle performance. The preparation is easy to realize industrialization and has low cost.
Although the above patent adopts graphene-loaded negative electrode particles (carbon and silicon materials), which is similar to the technical scheme of the present invention in view of surface, the problem that the conventional negative electrode material is easily expanded to cause the failure of the negative electrode material is solved by only coating the negative electrode material with graphene, and the technical problem that the rear surface of the negative electrode sheet made of graphene and other negative electrode materials is rough cannot be solved.
In addition, in the prior art, the adhesion between the negative electrode slurry and the copper foil of the negative electrode current collector after coating and curing is low, and the negative electrode slurry is easy to fall off in the later period, so that the service life of the battery is influenced.
Disclosure of Invention
In order to solve the technical problems, the invention provides graphene-titanium dioxide composite negative electrode slurry for a lithium ion battery and a preparation method thereof.
The technical scheme of the invention is as follows: the graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery is characterized by comprising the following components in parts by weight:
94-96 parts of graphene-titanium dioxide composite aerogel powder,
0-3 parts of a conductive agent,
0-2 parts of a dispersing agent,
1-3 parts of an adhesive agent,
0-1 part of a thickening agent,
140 portions of water and 160 portions.
The negative electrode slurry contains the graphene-titanium dioxide composite aerogel material, the specific surface area is large, the flexibility is high, and after the graphene-titanium dioxide composite aerogel material is coated on the surface of a negative electrode sheet and solidified, the surface of the obtained negative electrode sheet is smooth and has a weak rough feeling, so that the diaphragm can be effectively prevented from being pierced, and the service life of a battery is prolonged.
As a further preferred method, the preparation method of the graphene-titanium dioxide composite aerogel fine particles is as follows:
a) and carrying out ultrasonic washing on the graphene oxide, and drying under a negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:1-2, fully stirring, adding anhydrous ethanol with the mass being 10-30 times that of the graphene oxide, adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain a liquid A; uniformly mixing 1-2mol/L of glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 3-5:15-25:3-7 to obtain liquid B.
c) Dripping the liquid B into the liquid A with the mass of 2-3 times of that of the liquid B under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 1-2 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 200-300 ℃ in a reducing atmosphere, carrying out reduction reaction for 2-4h, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
The invention utilizes a special process to prepare graphene-titanium dioxide composite aerogel powder, and specifically comprises the following steps:
in step a), the graphene oxide is subjected to ultrasonic washing before reaction, and is dried under a negative pressure condition. Wherein the ultrasonic washing has the function of releasing impurities originally adsorbed between graphene oxide sheet layers; the effect of the negative pressure is to remove air between the graphene oxide sheets by using the air pressure difference. The treatment can release the adsorption capacity of the graphene to the maximum extent, improve the adsorbability of the graphene and facilitate subsequent operation.
In the step b) and the step c), the graphene oxide is added into the butyl titanate, so that the butyl titanate of the graphene oxide fully penetrates into the space between the lamellar structures of the graphene oxide. Then adding ethanol to prepare a liquid A, and dropwise adding the liquid B into the liquid A to hydrolyze the butyl titanate. In this process, since a large amount of butyl titanate is adsorbed between graphene oxide lamellar structures, a hydrolysis reaction of butyl titanate occurs between the lamellar structures of graphene oxide. Hydrolysis is exothermic reaction, and is comparatively violent to generate the titanium dioxide colloid between lamellar structure, the existence of heat and titanium dioxide colloid can strut graphite alkene lamellar structure, from making the stripping degree of graphite alkene improve, has bigger deformation space, and the flexibility increases. On the other hand, since titanium dioxide is coated with flexible single-layer graphene, the roughness thereof is also reduced. When the graphene-titanium dioxide composite aerogel is used as a negative electrode material and coated on the surface of a negative current collector for curing, the smoothness of the surface of a negative electrode piece can be improved, and the diaphragm is not easy to pierce. Although the technical solution of patent 201210533334.6 mentioned in the background of the present invention is similar to the technical solution of the present invention in a view of surface, it is only to coat the negative electrode material with graphene to solve the technical problem that the negative electrode material is easy to expand and the negative electrode material is ineffective, and the addition of graphene is after the hydrolysis reaction, so the amount of silica colloid directly generated in the graphene lamellar structure is small and the distance between graphene lamellar structures cannot be sufficiently expanded. The coating negative electrode material mainly depends on the physical adsorption of graphene; on the other hand, the patent 201210533334.6 does not recognize the technical problem to be solved by the present invention, and therefore, it cannot solve the technical problem that the rear surface of the negative electrode sheet made of graphene and other negative electrode materials is rough.
In addition, the mass ratio of the graphene oxide to the butyl titanate is specially adjusted in the step c), and the using amount of the butyl titanate is increased, so that the butyl titanate is saturated and loaded between graphene oxide lamellar structures, and the lamellar spacing is increased.
When the liquid B is dripped, the liquid A contains sodium bicarbonate, the sodium bicarbonate reacts with glacial acetic acid after being combined, carbon dioxide is released, and the porosity of sol can be increased in the sol generation process, so that the specific surface area of the cathode material is increased, and the battery performance is improved.
As a further preferred, in step a), the graphene oxide is modified by hydroxylation: adding graphene oxide into water to prepare graphene oxide dispersion liquid with the concentration of 3-7wt%, adding potassium hydroxide with the mass of 0.2-0.4 time that of the graphene oxide into the solution, heating to 85-95 ℃, reacting for 6-8h, and filtering, washing and drying to obtain the hydroxylated graphene oxide.
According to the titanium dioxide sol prepared by the sol-gel method, titanium dioxide is actually in the form of titanium hydroxide to form colloid through hydroxyl, and the invention utilizes the point that the hydroxylation modification is carried out on graphene oxide, so that the hydroxyl on the graphene oxide can be combined with the titanium hydroxide to form hydrogen bonds or other chemical bonds, and the graphene oxide can participate in the sol forming reaction. Therefore, in the aging process of the sol, the oxidized graphene and the titanium dioxide are fully bonded, the titanium dioxide is locked between the lamellar structures of the oxidized graphene, and the stability of the oxidized graphene is improved.
In addition, another advantage of the hydroxylation modification of the graphene oxide is that the modified graphene oxide is easier to combine with the copper foil of the negative current collector, and the adhesion of the negative slurry on the surface of the copper foil is improved. However, the higher the hydroxylation modification degree is, the better the hydroxylation modification degree is, the team of the present invention finds that the electrical conductivity of the graphene oxide is affected to a certain extent after the hydroxylation modification, so that the modification degree needs to be strictly controlled according to actual conditions.
Further preferably, in step c), the dropping rate of the liquid B is 1 to 2 mL/s.
As a further preference, in step e), the drying conditions of the supercritical fluid are 6-8MPa of pressure, 40-50 ℃ of temperature and 8-12h of time.
As a further preference, the binder is polytetrafluoroethylene or styrene butadiene rubber.
As a further preferred, the conductive agent is carbon nanotubes or Super P.
As a further preference, the dispersant is polyvinylpyrrolidone.
As a further preferred, the thickener is sodium carboxymethyl cellulose.
A preparation method of graphene-titanium dioxide composite negative electrode slurry for a lithium ion battery comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The invention has the following beneficial effects:
1. the negative electrode slurry contains the graphene-titanium dioxide composite aerogel material, the specific surface area is large, the flexibility is high, and after the graphene-titanium dioxide composite aerogel material is coated on the surface of a negative electrode sheet and solidified, the surface of the obtained negative electrode sheet is smooth and has a weak rough feeling, so that the diaphragm can be effectively prevented from being pierced, and the service life of a battery is prolonged.
2. The cathode slurry has high adhesion with a cathode current collector after being cured, is not easy to fall off, and can prolong the service life of the battery.
Detailed Description
The following is a detailed description of embodiments of the invention, but the invention can be implemented in many different ways, as defined and covered by the claims.
Example 1
The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery comprises the following components in parts by weight:
95 parts of graphene-titanium dioxide composite aerogel powder, 1.5 parts of Super P, 1 part of polyvinylpyrrolidone, 2 parts of polytetrafluoroethylene, 0.5 part of sodium carboxymethylcellulose and 150 parts of water.
The preparation method of the graphene-titanium dioxide composite negative electrode slurry comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
a) and carrying out ultrasonic washing on the graphene oxide, and drying under a negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:1.5, fully stirring, adding anhydrous ethanol with the mass being 20 times that of the graphene oxide, then adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain liquid A. Uniformly mixing 1.5mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 4:20:5 to obtain liquid B.
c) Dropwise adding the liquid B into the liquid A with the mass being 2.5 times of that of the liquid B at the dropwise adding speed of 1.5mL/s under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 1.5 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 7MPa, the temperature is 45 ℃ and the time is 10 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 250 ℃ in a reducing atmosphere, carrying out reduction reaction for 3 hours, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
Example 2
The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery comprises the following components in parts by weight:
95 parts of graphene-titanium dioxide composite aerogel powder, 1.5 parts of Super P, 1 part of polyvinylpyrrolidone, 2 parts of polytetrafluoroethylene, 0.5 part of sodium carboxymethylcellulose and 150 parts of water.
The preparation method of the graphene-titanium dioxide composite negative electrode slurry comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
hydroxylation modification of graphene oxide: adding graphene oxide into water to prepare a graphene oxide dispersion liquid with the concentration of 5 wt%, adding potassium hydroxide with the mass of 0.3 time that of the graphene oxide into the solution, heating to 90 ℃, reacting for 7h, filtering, washing and drying to obtain the hydroxylated graphene oxide.
a) And (3) carrying out ultrasonic washing on the hydroxylated graphene oxide, and drying under the negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:1.5, fully stirring, adding anhydrous ethanol with the mass being 20 times that of the graphene oxide, then adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain liquid A. Uniformly mixing 1.5mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 4:20:5 to obtain liquid B.
c) Dropwise adding the liquid B into the liquid A with the mass being 2.5 times of that of the liquid B at the dropwise adding speed of 1.5mL/s under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 1.5 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 7MPa, the temperature is 45 ℃ and the time is 10 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 250 ℃ in a reducing atmosphere, carrying out reduction reaction for 3 hours, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
Example 3
The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery comprises the following components in parts by weight:
94 parts of graphene-titanium dioxide composite aerogel powder, 3 parts of carbon nano tubes, 0.5 part of polyvinylpyrrolidone, 1.5 parts of styrene butadiene rubber, 1 part of sodium carboxymethylcellulose and 140 parts of water.
The preparation method of the graphene-titanium dioxide composite negative electrode slurry comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
hydroxylation modification of graphene oxide:
adding graphene oxide into water to prepare graphene oxide dispersion liquid with the concentration of 3 wt%, adding potassium hydroxide with the mass of 0.2 time that of the graphene oxide into the solution, heating to 85 ℃, reacting for 8 hours, and filtering, washing and drying to obtain the hydroxylated graphene oxide.
a) And (3) carrying out ultrasonic washing on the hydroxylated graphene oxide, and drying under the negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:1, fully stirring, adding anhydrous ethanol with the mass being 10 times that of the graphene oxide, adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain a liquid A. Uniformly mixing 1mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 3:15:3 to obtain liquid B.
c) Dropwise adding the liquid B into the liquid A with the mass being 2 times of that of the liquid B at the dropwise adding speed of 1mL/s under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 1 day at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 6MPa, the temperature is 40 ℃, and the time is 12 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 200-DEG C in a reducing atmosphere, carrying out reduction reaction for 4h, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
Example 4
The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery comprises the following components in parts by weight:
96 parts of graphene-titanium dioxide composite aerogel powder, 0.5 part of carbon nano tube, 2 parts of polyvinylpyrrolidone, 1 part of styrene butadiene rubber, 0.5 part of sodium carboxymethylcellulose and 160 parts of water.
The preparation method of the graphene-titanium dioxide composite negative electrode slurry comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
hydroxylation modification of graphene oxide, adding graphene oxide into water to prepare a graphene oxide dispersion liquid with the concentration of 7wt%, adding potassium hydroxide with the mass of 0.4 time that of the graphene oxide into the solution, heating to 95 ℃, reacting for 6 hours, filtering, washing and drying to obtain the hydroxylated graphene oxide.
a) And (3) carrying out ultrasonic washing on the hydroxylated graphene oxide, and drying under the negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:2, fully stirring, adding anhydrous ethanol with the mass being 30 times that of the graphene oxide, then adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain a liquid A. Uniformly mixing 2mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 5:25:7 to obtain liquid B.
c) Dropwise adding the liquid B into the liquid A with the mass being 3 times of that of the liquid B at the dropwise adding speed of 2mL/s under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 2 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 8MPa, the temperature is 50 ℃, and the time is 8 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 300 ℃ in a reducing atmosphere, carrying out reduction reaction for 2 hours, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
Example 5
The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery comprises the following components in parts by weight:
94.5 parts of graphene-titanium dioxide composite aerogel powder, 1.5 parts of Super P, 1.5 parts of polyvinylpyrrolidone, 2 parts of polytetrafluoroethylene, 0.5 part of sodium carboxymethylcellulose and 150 parts of water.
The preparation method of the graphene-titanium dioxide composite negative electrode slurry comprises the following steps:
1) weighing the components according to the proportion.
2) Firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under the stirring condition, and adding the rest water after uniformly dispersing.
3) And grinding the obtained slurry to obtain the cathode slurry.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
hydroxylation modification of graphene oxide: adding graphene oxide into water to prepare a graphene oxide dispersion liquid with the concentration of 6 wt%, adding potassium hydroxide with the mass of 0.3 time that of the graphene oxide into the solution, heating to 90 ℃, reacting for 8 hours, and filtering, washing and drying to obtain the hydroxylated graphene oxide.
a) And (3) carrying out ultrasonic washing on the hydroxylated graphene oxide, and drying under the negative pressure condition.
b) Adding graphene oxide into butyl titanate according to the mass ratio of 1:1.5, fully stirring, adding absolute ethyl alcohol of which the mass is 25 times that of the graphene oxide, then adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain liquid A. Uniformly mixing 1.5mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 4:20:6 to obtain liquid B.
c) Dropwise adding the liquid B into the liquid A with the mass of 2-3 times of that of the liquid B at the dropwise adding speed of 1.2mL/s under the stirring condition; obtaining the composite sol.
d) And (3) aging the composite sol for 2 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 7MPa, the temperature is 50 ℃, and the time is 9 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 260 ℃ in a reducing atmosphere, carrying out reduction reaction for 3 hours, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
Comparative example 1
The lithium ion battery cathode slurry comprises the following components in parts by weight:
55 parts of titanium dioxide, 40 parts of graphene, 1.5 parts of Super P, 1 part of polyvinylpyrrolidone, 2 parts of polytetrafluoroethylene, 0.5 part of sodium carboxymethylcellulose and 150 parts of water.
Comparative example 2
The lithium ion battery cathode slurry comprises the following components in parts by weight:
95 parts of graphene-titanium dioxide composite aerogel powder, 1.5 parts of Super P, 1 part of polyvinylpyrrolidone, 2 parts of polytetrafluoroethylene, 0.5 part of sodium carboxymethylcellulose and 150 parts of water.
The preparation method of the graphene-titanium dioxide composite aerogel particles comprises the following steps:
a) mixing butyl titanate with 15 times of ethanol by mass to obtain liquid A; uniformly mixing 1.5mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 4:20:5 to obtain liquid B.
b) Dropwise adding the liquid B into the liquid A with the mass being 2.5 times of that of the liquid B at the dropwise adding speed of 1.5mL/s under the stirring condition; a sol is obtained.
c) Adding graphene oxide with the mass of 2/3 of butyl titanate into the sol, and uniformly dispersing.
d) And (3) aging the composite sol for 1.5 days at room temperature, and washing to obtain the composite gel.
e) And (3) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid (the pressure is 7MPa, the temperature is 45 ℃ and the time is 10 hours) to obtain the graphene oxide-titanium dioxide composite aerogel.
f) And (3) heating the graphene oxide-titanium dioxide composite aerogel to 250 ℃ in a reducing atmosphere, carrying out reduction reaction for 3 hours, and grinding to obtain graphene-titanium dioxide composite aerogel powder.
The comparative example 1 directly adopts a physical mixed material of titanium dioxide and graphene, and the graphene-titanium dioxide composite aerogel powder of the comparative example 2 is prepared by adding graphene oxide after hydrolysis reaction.
The negative electrode slurry prepared in the examples 1-2 and the comparative examples 1-2 of the invention is coated on the surface of the negative electrode copper foil under the same condition to prepare a negative electrode sheet, and the adhesion of the surface coating of the negative electrode sheet is tested and the surface sense is evaluated.
The adhesion test method comprises the following steps: applying tension to two ends of the negative plate to enable the negative plate to be stretched in parallel, representing the adhesion condition of the negative coating by testing the peel strength of the negative coating,
| group number | Adhesion of coatings | Average thickness of coating | Sense of the surface of the coating |
| Example 1 | 16.2N/m | 25.0μm | Smooth hand feeling and weak roughness |
| Example 2 | 17.8N/m | 25.3μm | Smooth hand feeling and weak roughness |
| Comparative example 1 | 15.9N/m | 24.6μm | Rough hand feeling and fine and sharp spines |
| Comparative example 2 | 16.3N/m | 25.2μm | Rough hand feeling and fine and sharp spines |
The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. The graphene-titanium dioxide composite negative electrode slurry for the lithium ion battery is characterized by comprising the following components in parts by weight:
94-96 parts of graphene-titanium dioxide composite aerogel powder,
0-3 parts of a conductive agent,
0-2 parts of a dispersing agent,
1-3 parts of an adhesive agent,
0-1 part of a thickening agent,
140 portions of water and 160 portions of water;
the preparation method of the graphene-titanium dioxide composite aerogel powder comprises the following steps:
a) carrying out ultrasonic washing on graphene oxide, and drying under a negative pressure condition;
b) adding graphene oxide into butyl titanate according to the mass ratio of 1:1-2, fully stirring, adding anhydrous ethanol with the mass being 10-30 times that of the graphene oxide, adding sodium bicarbonate with saturated solubility, and uniformly mixing to obtain a liquid A; uniformly mixing 1-2mol/L glacial acetic acid, absolute ethyl alcohol and water according to the mass ratio of 3-5:15-25:3-7 to prepare liquid B;
c) dripping the liquid B into the liquid A with the mass of 2-3 times of that of the liquid B under the stirring condition; obtaining composite sol;
d) aging the composite sol for 1-2 days at room temperature, and washing to obtain composite gel;
e) fully replacing water and ethanol in the composite gel with n-hexane, taking out the gel, and drying with a carbon dioxide supercritical fluid to obtain the graphene oxide-titanium dioxide composite aerogel;
f) heating the graphene oxide-titanium dioxide composite aerogel to 200-300 ℃ in a reducing atmosphere, carrying out reduction reaction for 2-4h, and grinding to obtain graphene-titanium dioxide composite aerogel powder;
in the step a), the graphene oxide is subjected to hydroxylation modification:
adding graphene oxide into water to prepare graphene oxide dispersion liquid with the concentration of 3-7wt%, adding potassium hydroxide with the mass of 0.2-0.4 time that of the graphene oxide into the solution, heating to 85-95 ℃, reacting for 6-8h, and filtering, washing and drying to obtain the hydroxylated graphene oxide.
2. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein in the step c), the dropping speed of the liquid B is 1-2 mL/s.
3. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein in the step e), the drying condition of the supercritical fluid is 6-8MPa of pressure, 40-50 ℃ of temperature and 8-12h of time.
4. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein the binder is polytetrafluoroethylene or styrene butadiene rubber.
5. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein the conductive agent is carbon nanotubes or Super P.
6. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein the dispersant is polyvinylpyrrolidone.
7. The graphene-titanium dioxide composite anode slurry for the lithium ion battery according to claim 1, wherein the thickener is sodium carboxymethyl cellulose.
8. A method for preparing the graphene-titanium dioxide composite anode slurry for a lithium ion battery according to any one of claims 1 to 7, characterized by comprising the steps of:
1) weighing the components according to the proportion;
2) firstly, adding a thickening agent into water with a half formula amount, then sequentially adding an adhesive, a dispersing agent, a conductive agent and graphene-titanium dioxide composite aerogel powder under a stirring condition, and adding the rest water after uniformly dispersing;
3) and grinding the obtained slurry to obtain the cathode slurry.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102941042A (en) * | 2012-10-25 | 2013-02-27 | 北京理工大学 | Graphene/metal oxide hybrid aerogel, preparation method and applications thereof |
| CN104617280A (en) * | 2015-01-28 | 2015-05-13 | 哈尔滨工业大学 | Adhesive-free graphene/silicon electrode for lithium ion battery and preparation method thereof |
| CN106784648A (en) * | 2016-11-16 | 2017-05-31 | 江汉大学 | The preparation method of multi-walled carbon nano-tubes/titanium dioxide composite lithium ion battery cathode material |
Family Cites Families (2)
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| WO2014136073A1 (en) * | 2013-03-06 | 2014-09-12 | Ecole Polytechnique Federale De Lausanne (Epfl) | Titanium oxide aerogel composites |
-
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- 2017-12-28 CN CN201711459373.5A patent/CN108183218B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102941042A (en) * | 2012-10-25 | 2013-02-27 | 北京理工大学 | Graphene/metal oxide hybrid aerogel, preparation method and applications thereof |
| CN104617280A (en) * | 2015-01-28 | 2015-05-13 | 哈尔滨工业大学 | Adhesive-free graphene/silicon electrode for lithium ion battery and preparation method thereof |
| CN106784648A (en) * | 2016-11-16 | 2017-05-31 | 江汉大学 | The preparation method of multi-walled carbon nano-tubes/titanium dioxide composite lithium ion battery cathode material |
Non-Patent Citations (3)
| Title |
|---|
| "Mesoporous TiO2 Nanocrystals Grown in Situ on Graphene Aerogels for High Photocatalysis and Lithium-Ion Batteries";Bocheng Qiu等;《JOURNAL OF THE AMERICAN CHEMICAL SOCIETY》;20140408;第136卷;第5852-5855 * |
| "超亲水TiO2多孔薄膜的制备及成孔机理研究";杨春晓;《中国优秀硕士学位论文全文数据库（电子期刊）工程科技I辑》;20150115;第16-18页、第37-59页 * |
| Bocheng Qiu等."Mesoporous TiO2 Nanocrystals Grown in Situ on Graphene Aerogels for High Photocatalysis and Lithium-Ion Batteries".《JOURNAL OF THE AMERICAN CHEMICAL SOCIETY》.2014,第136卷第5852-5855. * |
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