CN113644239B - Silica composite material and preparation method thereof - Google Patents
Silica composite material and preparation method thereof Download PDFInfo
- Publication number
- CN113644239B CN113644239B CN202010345671.7A CN202010345671A CN113644239B CN 113644239 B CN113644239 B CN 113644239B CN 202010345671 A CN202010345671 A CN 202010345671A CN 113644239 B CN113644239 B CN 113644239B
- Authority
- CN
- China
- Prior art keywords
- calcination
- linear porous
- silica
- composite material
- negative electrode
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- 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
- H01M4/362—Composites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- 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
- H01M4/13—Electrodes for accumulators with non-aqueous electrolyte, e.g. for lithium-accumulators; Processes of manufacture thereof
- H01M4/131—Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
-
- 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
- H01M4/483—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides for non-aqueous cells
-
- 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
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Nanotechnology (AREA)
- Materials Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Crystallography & Structural Chemistry (AREA)
- Composite Materials (AREA)
- Inorganic Chemistry (AREA)
- Silicon Compounds (AREA)
- Battery Electrode And Active Subsutance (AREA)
Abstract
The present disclosure provides a silica composite comprising a linear porous scaffold and silica nanoparticles deposited in the pores of the linear porous scaffold; the pore diameter of the linear porous skeleton is 5-10nm, the porosity is 20-35%, and the particle size of the silica nano particles is 5-8nm; preferably, the pore diameter of the linear porous skeleton is 6-8nm, and the porosity is 25-30%; the particle size of the silica nano particles is 5-6nm. The composite material can be used as a negative electrode material to further relieve the stress generated by volume expansion in the charge and discharge process and improve the conductivity and mechanical strength of the silicon negative electrode material.
Description
Technical Field
The application relates to the technical field of lithium ion batteries, in particular to a silicon-oxygen composite material and a preparation method thereof.
Background
With the rapid development of the electric automobile industry, requirements on the energy density, the cycle life, the safety performance and the like of a matched power battery of an electric automobile are continuously improved. At present, most of negative electrode materials of lithium ion power batteries produced in mass on the market mainly comprise graphite, the multiplying power performance of the graphite negative electrode materials is poor, side reactions are more, the stability of a layered structure is required to be improved, and the market demands are difficult to meet. The silicon anode material is used as a novel anode material with the most potential, has the advantages of high theoretical capacity (4200 mAh/g), low lithium intercalation and deintercalation platform, abundant resources, good safety and the like, and is a main research direction of the anode material of the lithium ion power battery.
However, during charge and discharge, the silicon anode material accompanies a huge volumeThe change (up to 300% in volume) causes pulverization of the electrode material, loss of electrical contact, continuous rupture and repair of the SEI film, and rapid capacity decay. The theoretical capacity of silica (2600 mAh/g) is lower than that of silicon, the strength of Si-O bond is 2 times that of Si-Si bond, and Li generated in the first week reaction process 2 O、Li 4 SiO 4 The skeleton network is used for precipitation, and the skeleton network serves as a good in-situ buffer matrix, so that the volume effect of active metal silicon particles in the charge and discharge process is inhibited to a certain extent, but the problem caused by volume change cannot be completely eliminated, and the cycle stability of the skeleton network is still to be improved. In addition, in the first cycle, the generation of inert components in the silicon oxide brings about a large irreversible capacity, so that the first coulombic efficiency is low. These factors greatly limit the performance of the silica electrochemical performance and its practical application.
Therefore, a proper silicon anode material needs to be found, so that the cycle stability in the charge and discharge process can be effectively improved, and the first coulombic efficiency in the first cycle process can be improved.
Disclosure of Invention
The purpose of the present disclosure is to provide a silicon-oxygen composite material to relieve the stress generated by volume expansion in the charge and discharge process, and further improve the conductivity and mechanical strength of the silicon anode material.
In order to achieve the above object, the present disclosure provides, in one aspect, a silica composite material including a linear porous skeleton and silica nanoparticles deposited in pores of the linear porous skeleton; the pore diameter of the linear porous skeleton is 5-10nm, and the porosity is 20-35%; the particle size of the silica nano particles is 5-8nm; preferably, the pore diameter of the linear porous skeleton is 6-8nm, and the porosity is 25-30%; the particle size of the silica nano particles is 5-6nm.
Optionally, the material of the linear porous skeleton is at least one of multi-wall carbon nanotubes, carbon nanofibers and transition metal oxide nanorods; the transition metal oxide nano rod is Fe 3 O 4 Nanorods or Co 3 O 4 A nanorod.
Optionally, the composite material comprises a conductive layer wrapped on the surface of the linear porous framework; the thickness of the conductive layer is 50-100nm; preferably 50-70nm.
Optionally, the conductive layer is an amorphous carbon conductive layer.
Optionally, the conductive layer is made of a conductive polymer, and the conductive polymer is at least one of polydopamine, polyaniline, polypyrrole, polypyridine and polydiethylene thiophene.
In another aspect, the present disclosure provides a method of preparing a silicone composite, the method comprising the steps of:
s1, adding a linear porous framework precursor into a first alkaline solution, mixing with the linear porous framework precursor, drying, and performing first calcination to obtain a linear porous framework;
s2, dispersing the linear porous skeleton in water to obtain a dispersion liquid, uniformly mixing a silicon source material of the dispersion liquid, and carrying out hydrolysis treatment on the silicon source material to obtain a hydrolyzed material;
and S3, filtering the material subjected to the hydrolysis treatment to obtain filter residues, and performing second calcination on the filter residues in a reducing atmosphere.
Optionally, the linear porous skeleton precursor is a multi-wall carbon nanotube, a carbon nanofiber and a transition metal oxide nanorod; preferably, the transition metal oxide nanorods are Fe3O4 nanorods or Co3O4 nanorods; the silicon source material is silicate, preferably the silicate is methyl orthosilicate, ethyl orthosilicate and propyl orthosilicate; the first alkaline solution is an alcohol solution of alkali metal hydroxide, preferably the alcohol solution of alkali metal hydroxide is potassium hydroxide alcohol solution and/or sodium hydroxide alcohol solution; the concentration of the alkali metal hydroxide in the first alkaline solution is 0.1-0.2g/mL; the hydrolysis treatment is performed by adding a second alkaline solution, preferably ammonia water; the reducing atmosphere is hydrogen-argon mixed gas.
Optionally, in step S1, the conditions of the first calcination include: the first calcination is carried out in inert gas, the temperature rising rate of the first calcination is 2-5 ℃/min, the calcination temperature of the first calcination is 600-800 ℃, and the calcination time of the first calcination is 1.5-3h;
in step S2, the conditions for the second calcination include: calcining at 700-800 ℃ for 1-2h, wherein the hydrolysis conditions comprise: the temperature of the hydrolysis is 30-40 ℃, and the time of the hydrolysis is 12-18h; the dispersion is ultrasonic dispersion, the water for dispersion is distilled water and/or deionized water, and the conditions of ultrasonic dispersion comprise: the frequency of the ultrasonic dispersion is 20-40kHz, the specific power of the ultrasonic dispersion is 400-800W/L, and the ultrasonic dispersion time is 15-25min;
in step S3, the conditions for the second calcination include: the temperature of the second calcination is 700-800 ℃, and the time of the second calcination is 1-2h.
Optionally, the method further comprises: mixing the product obtained by the second calcination with water, conductive polymer monomers and an oxidant, performing in-situ polymerization of the conductive polymer, magnetically stirring under the action of the oxidant to obtain a product A, filtering and washing the product A in a weak acid solution to be neutral, and then performing drying treatment; the conductive polymer monomer is at least one selected from pyrrole, aniline and dopamine, and the weak acid solution is HF solution.
Optionally, the oxidizing agent is selected from FeCl 3 、H 2 O 2 And at least one of ammonium persulfate; the conditions for in situ polymerization of the conductive polymer include: in ice bath, magnetic stirring at constant speed of 500-600r/min for 10-20h at a temperature of-5 deg.C to-5 deg.C.
Optionally, the method further comprises: carrying out third calcination on the dried product in reducing gas; the conditions for the third calcination include: calcining at 700-800 deg.c for 1-2 hr; the reducing atmosphere is hydrogen-argon mixed gas.
In yet another aspect, the present disclosure provides a negative electrode.
In yet another aspect, the present disclosure provides a lithium battery.
Through the technical scheme, the silica composite material is integrally of a one-dimensional linear structure, is good in conductivity and small in expansion, and the porous framework not only limits the size of silica, but also can serve as a buffer matrix for relieving stress generated by volume expansion in the lithium intercalation and deintercalation process.
Additional features and advantages of the present disclosure will be set forth in the detailed description which follows.
Detailed Description
The following describes specific embodiments of the present disclosure in detail. It should be understood that the detailed description and specific examples, while indicating and illustrating the disclosure, are not intended to limit the disclosure.
In one aspect, the present disclosure provides a silica composite comprising a linear porous scaffold and silica nanoparticles deposited in the pores of the linear porous scaffold; the pore diameter of the linear porous skeleton is 5-10nm, and the porosity is 20-35%; the particle size of the silica nano particles is 5-8nm; preferably, the pore diameter is 6-8nm, the porosity is 25-30%, and the particle diameter is 5-6nm.
The silica composite material provided by the disclosure has a one-dimensional linear structure as a whole, is good in conductivity and small in expansion, and the porous framework not only limits the size of silica oxide, but also can be used as a buffer matrix to relieve the stress generated by volume expansion in the lithium intercalation and deintercalation process. In addition, the particle size of the silica nano particles is further limited by limiting the pore structure of the one-dimensional porous framework, and the volume expansion in the charge and discharge process can be effectively relieved through the porous structure of the one-dimensional porous framework and the conductive polymer coating layer wrapping the surface of the one-dimensional porous framework.
Preferably, the material of the linear porous skeleton is at least one of multi-wall carbon nanotubes, carbon nanofibers and transition metal oxide nanorods; the transition metal oxide nano rod is Fe 3 O 4 Nanorods or Co 3 O 4 A nanorod.
According to the present disclosure, the composite material comprises a conductive layer wrapped on the surface of the one-dimensional porous skeleton; the thickness of the conductive layer is 50-100nm; preferably 50-70nm. The conductive layer further improves the conductivity and mechanical strength of the material, so that direct contact between the silicon oxide nano particles and electrolyte is blocked, and the generated SEI film is more stable.
According to the disclosure, the conductive layer is preferably an amorphous carbon conductive layer, so that the conductive performance of the material is further improved, the contact area between the silicon oxide nano particles and the electrolyte is improved, and the generation of side reactions is reduced.
Preferably, the conductive layer is made of a conductive polymer with good conductivity, and the conductive polymer is at least one of polydopamine, polyaniline, polypyrrole, polypyridine and polydiethylene thiophene.
In another aspect, the present disclosure provides a method of preparing a silicone composite, the method comprising the steps of:
s1, adding a linear porous framework precursor into a first alkaline solution, mixing with the linear porous framework precursor, drying, and performing first calcination to obtain a linear porous framework;
s2, dispersing the linear porous skeleton in water to obtain a dispersion liquid, uniformly mixing a silicon source material of the dispersion liquid, and carrying out hydrolysis treatment on the silicon source material to obtain a hydrolyzed material;
and S3, filtering the material subjected to the hydrolysis treatment to obtain filter residues, and performing second calcination on the filter residues in a reducing atmosphere.
According to the present disclosure, a linear porous skeleton precursor is selected as a basic skeleton, a first alkaline solution is added, and the porous skeleton is prepared by reacting and pore-forming under a high-temperature inert atmosphere; adding a silicon source, hydrolyzing, and generating silicon oxide in situ in the linear porous framework; calcining the silica composite material at high temperature under a reducing atmosphere, thereby obtaining the silica composite material comprising a linear porous framework and silica nanoparticles deposited in pores of the linear porous framework. The silica composite material has the pore diameter, the porosity and the particle diameter of deposited silica particles with proper range by adjusting the specific reaction conditions of the steps, so that the ideal silica composite material is obtained.
According to the present disclosure, the linear porous skeleton precursor is a multiwall carbon nanotube, a carbon nanofiberAnd nanorods; preferably the transition metal oxide nanorods; the transition metal oxide nano particles are Fe 3 O 4 Nanorods or Co 3 O 4 A nanorod; the silicon source material is silicate, preferably the silicate is methyl orthosilicate, ethyl orthosilicate and propyl orthosilicate; the first alkaline solution is an alcohol solution of alkali metal hydroxide, preferably the alcohol solution of alkali metal hydroxide is potassium hydroxide alcohol solution and/or sodium hydroxide alcohol solution; the concentration of the alkali metal hydroxide in the first alkaline solution is 0.1-0.2g/mL; the hydrolysis treatment is carried out by adding a second alkaline solution, preferably ammonia water, wherein the percentage of the ammonia water can be 25-28%; the weak acid solution is HF solution; the reducing atmosphere is hydrogen-argon mixture, wherein the ratio of hydrogen to argon in the hydrogen-argon mixture can be 1:9-19.
The present disclosure can control the relative mass ratio of the linear porous scaffold in the silica composite to the silica nanoparticles deposited in the pores of the linear porous scaffold by controlling the amounts of the linear porous scaffold precursor and the silicon source material. In the present disclosure, the first alkaline solution may be used in an amount of 15 to 30mL relative to 1g of the linear porous skeleton precursor; the amount of water used for dispersion may be 80 to 120mL and the amount of the silicon source material may be 8 to 15mL, relative to 1g of the linear porous skeleton.
According to the present disclosure, in step S1, the conditions of the first calcination include: the first calcination is carried out in inert gas, the temperature rising rate of the first calcination is 2-5 ℃/min, the calcination temperature of the first calcination is 600-800 ℃, and the calcination time of the first calcination is 1.5-3h; in step S2, the conditions for the second calcination include: calcining at 700-800 ℃ for 1-2h, wherein the hydrolysis conditions comprise: the temperature of the hydrolysis is 30-40 ℃, and the time of the hydrolysis is 12-18h; the dispersion is ultrasonic dispersion, the water for dispersion is distilled water and/or deionized water, and the conditions of ultrasonic dispersion comprise: the frequency of the ultrasonic dispersion is 20-40kHz, the specific power of the ultrasonic dispersion is 400-800W/L, and the ultrasonic dispersion time is 15-25min; in step S3, the conditions for the second calcination include: the temperature of the second calcination is 700-800 ℃, and the time of the second calcination is 1-2h.
In accordance with the present disclosure, the method of preparing a silicone composite may further comprise: mixing the product obtained by the second calcination with water, conductive polymer monomers and an oxidant, carrying out in-situ polymerization of the conductive polymer to obtain a product A, filtering and washing the product A in a weak acid solution to be neutral, and then carrying out drying treatment; the conductive polymer monomer is at least one selected from pyrrole, aniline and dopamine, and the weak acid solution is HF solution. According to the preparation method, pyrrole, aniline or dopamine is added after the product obtained through the second calcination is dispersed in deionized water, so that the silicon-oxygen composite material is provided with the conductive polymer coating layer coated on the surface of the one-dimensional porous framework, the conductivity and mechanical strength of the material are further improved, direct contact between silicon-oxygen nano particles and electrolyte is blocked, and the generated SEI film is more stable.
Preferably, the oxidizing agent is selected from FeCl 3 、H 2 O 2 And at least one of ammonium persulfate; the conditions for in situ polymerization of the conductive polymer include: magnetic stirring at constant speed of 500-600r/min for 10-20h at a temperature of-5 deg.C to-5 deg.C.
Further preferably, the method of preparing a silicone composite may further comprise: carrying out third calcination on the dried product in reducing gas; the conditions for the third calcination include: calcining at 700-800 deg.c for 1-2 hr; the reducing atmosphere is hydrogen-argon mixture, wherein the ratio of hydrogen to argon in the hydrogen-argon mixture can be 1:9-19. The amorphous carbon coating layer is obtained by performing third calcination on a silica composite material provided with a conductive polymer coating layer coated on the surface of a one-dimensional porous skeleton in reducing gas, so that the conductive polymer coating layer is further carbonized.
In yet another aspect, the present disclosure provides a negative electrode comprising a current collector and a negative electrode material coated on the current collector, the negative electrode material being a silicon-oxygen composite of the present disclosure. The silicon-oxygen composite material is used as the silicon anode material to relieve the stress generated by volume expansion of the existing silicon anode material in the charge and discharge process, so that the conductivity and the mechanical strength of the silicon anode material are further improved.
In yet another aspect, the present disclosure provides a lithium battery comprising a positive electrode and a negative electrode, the negative electrode comprising a current collector and a negative electrode material coated on the current collector, the negative electrode material being a silicone composite of the present disclosure.
The present disclosure is further illustrated by the following examples, but the present disclosure is not limited thereby.
Materials, reagents, instruments and equipment used in the examples of the present disclosure were commercially available, where carbon nanofibers were purchased from Sigma-
Example 1
Dissolving 3g of potassium hydroxide in 20ml of ethanol solution, adding 1g of carbon nanofiber, uniformly mixing, putting into a blowing drying oven at 180 ℃ for drying, and carrying out first calcination on the dried product to obtain the linear porous skeleton. Wherein, the conditions of the first calcination are: heating to 800 ℃ at a heating rate of 5 ℃/min, and calcining for 2h.
Taking 0.5g of deionized water with a linear porous framework, washing to be neutral, then performing ultrasonic dispersion in the deionized water, adding 5ml of ethyl orthosilicate, stirring for 30min, adding 5ml of 25% ammonia water, hydrolyzing for 14h at the constant temperature of 35 ℃, filtering and washing the hydrolyzed product, and performing second calcination to obtain the silica composite material of the embodiment. Wherein, the conditions of ultrasonic dispersion are as follows: the frequency is 30kHz, the specific power of the ultrasonic dispersion is 600W/L, and the ultrasonic dispersion time is 20min; the conditions for the second calcination were: calcining for 1.5h at the high temperature of 730 ℃ in a hydrogen-argon mixed gas, wherein the hydrogen-argon ratio in the hydrogen-argon mixed gas is 1:19.
example 2
Dissolving 3g of potassium hydroxide in 20ml of ethanol solution, adding 1g of carbon nanofiber, uniformly mixing, putting into a blowing drying oven at 180 ℃ for drying, and carrying out first calcination on the dried product to obtain the linear porous skeleton. Wherein, the conditions of the first calcination are: heating to 800 ℃ at a heating rate of 5 ℃/min, and calcining for 2h.
Taking 0.5g of deionized water with a linear porous framework, washing to be neutral, then dispersing in deionized water by ultrasonic, adding 5ml of tetraethoxysilane, stirring for 30min, adding 5ml of 25% ammonia water, hydrolyzing for 14h at the constant temperature of 35 ℃, filtering and washing the hydrolyzed product, and then performing second calcination. Wherein, the conditions of ultrasonic dispersion are as follows: the frequency is 30kHz, the specific power of the ultrasonic dispersion is 600W/L, and the ultrasonic dispersion time is 20min; the conditions for the second calcination were: calcining for 1.5h at the high temperature of 730 ℃ in a hydrogen-argon mixed gas, wherein the hydrogen-argon ratio in the hydrogen-argon mixed gas is 1:19.
dispersing the product obtained by the second calcination in 50ml of deionized water, adding 5g of dopamine monomer and 1g of ammonium persulfate, magnetically stirring in an ice bath at a constant speed of 550r/min for 12 hours, filtering and washing to obtain a product A, adding the product A into 10ml of 5% HF solution, stirring for 10 minutes, filtering and washing to be neutral, and drying to obtain the silicon-oxygen composite material of the embodiment.
Example 3
This example prepares a silicone composite material according to the method of example 2. Except that the silica composite material prepared in example 2 was subjected to a third calcination. Wherein, the conditions of the third calcination are as follows: calcining for 1h at the high temperature of 800 ℃ in the hydrogen-argon mixed gas.
Example 4
This example prepares a silicone composite material according to the method of example 2. In contrast, the conditions for the first calcination in this example were: heating to 750 ℃ at a heating rate of 3 ℃/min, and calcining for 2h.
Example 5
This example prepares a silicone composite material according to the method of example 2. In contrast, the conditions for the first calcination in this example were: heating to 700 ℃ at a heating rate of 2 ℃/min, and calcining for 2h.
Example 6
This example prepares a silicone composite material according to the method of example 2. In contrast, the conditions for the second calcination in this example were: calcining in hydrogen-argon mixture at 700 ℃ for 1.5h.
Example 7
This example prepares a silicone composite material according to the method of example 2. In contrast, the conditions for the second calcination in this example were: calcining for 3 hours at the high temperature of 800 ℃ in the hydrogen-argon mixed gas.
Example 8
This example prepares a silicone composite material according to the method of example 2. In contrast, the conditions for the first calcination in this example were: heating to 730 ℃ at a heating rate of 3 ℃/min, and calcining for 2h; the conditions for the second calcination were: calcining for 1h at the high temperature of 800 ℃ in the hydrogen-argon mixed gas.
Example 9
This example prepares a silicone composite material according to the method of example 2. Except that the product obtained by the second calcination was dispersed in 50ml of deionized water, 3g of pyrrole and 1g of ammonium persulfate as an oxidant were added, and the mixture was magnetically stirred in an ice bath at a constant speed of 550r/min for 15 hours, and the product A was obtained after filtration and washing.
Example 10
This example prepares a silicone composite material according to the method of example 2. In contrast, the product from the second calcination was dispersed in 50ml of deionized water, 5g of aniline and 5ml of H were added 2 O 2 And (3) magnetically stirring the mixture in an ice bath at a constant speed of 550r/min for 35 hours, and filtering and washing the mixture to obtain a product A.
Example 11
This example prepares a silicone composite material according to the method of example 2. Except that carbon nanofibers are replaced with Fe 3 O 4 A nanorod.
Comparative example 1
This comparative example a silicone composite was prepared as in example 1. The conditions for the first calcination in this comparative example are, differently: heating to 850 ℃ at a heating rate of 10 ℃/min, and calcining for 1h.
Comparative example 2
This comparative example a silicone composite was prepared as in example 1. The conditions for the second calcination in this comparative example are, differently: calcining in hydrogen-argon mixture at 800 ℃ for 2h.
Comparative example 3
This example prepares a silicone composite material according to the method of example 1. The conditions for the first calcination in this comparative example are, differently: heating to 900 ℃ at a heating rate of 15 ℃/min, and calcining for 1h; the conditions for the second calcination were: calcining for 0.5h at the high temperature of 1000 ℃ in hydrogen-argon mixed gas; wherein, the ratio of hydrogen to argon in the hydrogen to argon mixture is 1:19.
comparative example 4
A silicon oxygen negative electrode material available from OTC company.
Test example 1
The pore diameters, porosities, particle diameters of silica nanoparticles, and thicknesses of conductive polymer coating layers of the linear porous skeletons of the silica composite materials prepared in examples 1 to 11 and comparative examples 1 to 3 and the commercially available silica anode material of comparative example 4 were measured, and the measurement results are shown in table 1.
Table 1:
| group of | Aperture (nm) | Porosity (%) | Particle size (nm) of silica nanoparticles | Coating thickness (nm) |
| Example 1 | 6-8 | 25％ | 5-6 | / |
| Example 2 | 6-8 | 26％ | 5-6 | 65 |
| Example 3 | 6-8 | 28％ | 5-6 | 55 |
| Example 4 | 8-10 | 20％ | 5-6 | 64 |
| Example 5 | 6-10 | 33％ | 5-7 | 65 |
| Example 6 | 5-8 | 29％ | 7-8 | 63 |
| Example 7 | 6-9 | 27％ | 6-8 | 63 |
| Example 8 | 5-10 | 32％ | 6-8 | 66 |
| Example 9 | 6-9 | 25％ | 5-7 | 70 |
| Example 10 | 6-8 | 28％ | 5-6 | 60 |
| Example 11 | 7-10 | 28％ | 5-8 | 62 |
| Comparative example 1 | 15-18 | 10％ | 12-15 | / |
| Comparative example 2 | 20-25 | 18％ | 22-25 | / |
| Comparative example 3 | 20-30 | 17％ | 25-30 | / |
| Comparative example 4 | / | / | 100nm or more | / |
Test example 2
The silicon oxide composite materials prepared in examples 1-11 and comparative examples 1-3 and the commercially available silicon oxide negative electrode material of comparative example 4 are respectively used as negative electrode active materials and are mixed with acetylene black and sodium carboxymethyl cellulose according to a proportion of 8:1:1, uniformly mixing and coating the mixture on a copper foil to obtain a working electrode plate; taking a metal lithium sheet as a counter electrode; the PE/PP composite membrane is used as an ion exchange membrane, and a button cell is manufactured by adopting a conventional method in the field.
The button cell was discharged to 0.005V at normal temperature with a constant current of 0.5A, then charged to 1.5V with a constant current of 0.5mA, charged for 100 cycles in a cycle, the discharge capacity and charge capacity of the cell were recorded, and the first reversible capacity, the first coulombic efficiency and the remaining capacity after 100 cycles of charging of the cell were calculated, and specific data are shown in table 2.
The first coulombic efficiency calculation formula: first discharge capacity/first charge capacity 100%
Table 2:
| group of | First reversible capacity mAh/g | First coulombic efficiency% | 100 circles of residual capacity mAh/g |
| Example 1 | 1716.99 | 68.6 | 910 |
| Example 2 | 1822.8 | 75.3 | 1518.9 |
| Example 3 | 1795.185 | 78.6 | 1554.72 |
| Example 4 | 1732.705 | 74.5 | 1368.2 |
| Example 5 | 1795.4 | 73.2 | 1294.4 |
| Example 6 | 1781.25 | 75.4 | 1343.1 |
| Example 7 | 1736.25 | 70.6 | 1202 |
| Example 8 | 1726.1 | 76.4 | 1099.21 |
| Example 9 | 1697.25 | 73.6 | 1156.5 |
| Example 10 | 1659.85 | 75.1 | 1085 |
| Example 11 | 1641.45 | 72.6 | 1199.64 |
| Comparative example 1 | 1655.05 | 68.9 | 856.23 |
| Comparative example 2 | 1662.95 | 66.45 | 788.915 |
| Comparative example 3 | 1639.25 | 65.4 | 694.805 |
| Comparative example 4 | 1874.988 | 63.7 | 329.346 |
Test example 3
The working electrode sheet and button cell were fabricated according to the method of test example 2. The original thickness of each set of sample pole pieces was measured with a micrometer prior to assembly of the button cell. After 50 cycles of the coin cell, the cell was completely discharged, the coin cell was disassembled, the negative electrode sheet was taken out, washed clean with DMC solution, air-dried, and then subjected to thickness test, and the expansion ratio was calculated, and specific data are shown in Table 3.
Wherein, the calculation formula of the expansion rate is: (T) 100 -T 0 )/T 0
Table 3:
the silicon-oxygen composite material is integrally of a one-dimensional linear structure, is good in conductivity and small in expansion, and the porous framework not only limits the size of silicon oxide, but also can be used as a buffer matrix for relieving stress generated by volume expansion in the lithium intercalation and deintercalation process. From the data in tables 2-3, it can be seen that the button cell prepared from the silica composite material of the present disclosure has a higher first reversible capacity and first coulombic efficiency, and the remaining capacity after 100 cycles of charging is higher; and after 50 times of charging cycle, the battery expansion rate of the button battery prepared by using the silica composite material is greatly reduced. Therefore, the silicon oxide composite material can be used as a battery anode material to effectively relieve volume expansion in the charge and discharge process.
The preferred embodiments of the present disclosure have been described in detail above, but the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and all the simple modifications belong to the protection scope of the present disclosure.
In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, the present disclosure does not further describe various possible combinations.
Moreover, any combination between the various embodiments of the present disclosure is possible as long as it does not depart from the spirit of the present disclosure, which should also be construed as the disclosure of the present disclosure.
Claims (16)
1. A silica composite material, characterized in that the silica composite material comprises a linear porous skeleton and silica nanoparticles deposited in the pores of the linear porous skeleton;
the pore diameter of the linear porous skeleton is 5-10nm, and the porosity is 20-35%; the particle size of the silica nano particles is 5-8nm; the silica composite material comprises a conductive layer wrapped on the surface of the linear porous framework;
the preparation method of the silicon-oxygen composite material comprises the following steps:
s1, adding a linear porous framework precursor into a first alkaline solution, mixing, drying, and performing first calcination to obtain a linear porous framework;
s2, dispersing the linear porous skeleton in water to obtain a dispersion liquid, uniformly mixing the dispersion liquid with a silicon source material, and carrying out hydrolysis treatment on the silicon source material to obtain a hydrolyzed material;
and S3, filtering the material subjected to the hydrolysis treatment to obtain filter residues, and performing second calcination on the filter residues in a reducing atmosphere.
2. The silica composite of claim 1, wherein the linear porous scaffold has a pore size of 6-8nm and a porosity of 25-30%; the particle size of the silica nano particles is 5-6nm.
3. The silica composite according to claim 1, wherein the material of the linear porous skeleton is at least one of multi-walled carbon nanotubes, carbon nanofibers, and transition metal oxide nanorods; the transition metal oxide nano rod is Fe 3 O 4 Nanorods or Co 3 O 4 A nanorod.
4. The silicone composite according to claim 1, wherein the conductive layer has a thickness of 50-100nm.
5. The silicone composite of claim 4, wherein the conductive layer has a thickness of 50-70nm.
6. The silicone composite of claim 4, wherein the conductive layer is an amorphous carbon conductive layer.
7. The silicone composite of claim 4, wherein the conductive layer is a conductive polymer that is at least one of polydopamine, polyaniline, polypyrrole, polypyridine, and polydiethylene thiophene.
8. A method of preparing a silicone composite as set forth in any one of claims 1-7, comprising the steps of:
s1, adding a linear porous framework precursor into a first alkaline solution, mixing, drying, and performing first calcination to obtain a linear porous framework;
s2, dispersing the linear porous skeleton in water to obtain a dispersion liquid, uniformly mixing the dispersion liquid with a silicon source material, and carrying out hydrolysis treatment on the silicon source material to obtain a hydrolyzed material;
and S3, filtering the material subjected to the hydrolysis treatment to obtain filter residues, and performing second calcination on the filter residues in a reducing atmosphere.
9. The method of claim 8, wherein the linear porous scaffold precursor is at least one of multi-walled carbon nanotubes, carbon nanofibers, and transition metal oxide nanorods; the silicon source material is silicate ester; the first alkaline solution is an alcohol solution of alkali metal hydroxide; the concentration of the alkali metal hydroxide in the first alkaline solution is 0.1-0.2g/mL; the hydrolysis treatment is performed by adding a second alkaline solution.
10. The method of claim 9, wherein the transition metal oxide nanorods are Fe 3 O 4 Nanorods or Co 3 O 4 A nanorod; the silicate is methyl orthosilicate, ethyl orthosilicate or propyl orthosilicate; the alcohol solution of the alkali metal hydroxide is potassium hydroxide alcohol solution and/or sodium hydroxide alcohol solution; the second alkaline solution is ammonia water; the reducing atmosphere is hydrogen-argon mixed gas.
11. The method of claim 8, wherein in step S1, the conditions of the first calcination include: the first calcination is carried out in inert gas, the temperature rising rate of the first calcination is 2-5 ℃/min, the calcination temperature of the first calcination is 600-800 ℃, and the calcination time of the first calcination is 1.5-3h;
in step S2, the conditions of the hydrolysis treatment include: the temperature of the hydrolysis treatment is 30-40 ℃, and the time of the hydrolysis treatment is 12-18h; the dispersion is ultrasonic dispersion, the water for dispersion is distilled water and/or deionized water, and the conditions of ultrasonic dispersion comprise: the frequency of the ultrasonic dispersion is 20-40kHz, the specific power of the ultrasonic dispersion is 400-800W/L, and the ultrasonic dispersion time is 15-25min;
in step S3, the conditions for the second calcination include: the temperature of the second calcination is 700-800 ℃, and the time of the second calcination is 1-2h.
12. The method according to any one of claims 8-11, wherein the method further comprises: mixing the product obtained by the second calcination with water, conductive polymer monomers and an oxidant, carrying out in-situ polymerization of the conductive polymer to obtain a product A, filtering and washing the product A in a weak acid solution to be neutral, and then carrying out drying treatment; the conductive polymer monomer is at least one selected from pyrrole, aniline and dopamine, and the weak acid solution is HF solution.
13. The method of claim 12, wherein the oxidizing agent is selected from feci 3 、H 2 O 2 And at least one of ammonium persulfate; the conditions for in situ polymerization of the conductive polymer include: magnetic stirring at constant speed of 500-600r/min for 10-20h at a temperature of-5 deg.C to-5 deg.C.
14. The method of claim 12, wherein the method further comprises: carrying out third calcination on the dried product in reducing gas; the conditions for the third calcination include: calcining at 700-800 deg.c for 1-2 hr; the reducing atmosphere is hydrogen-argon mixed gas.
15. A negative electrode comprising a current collector and a negative electrode material coated on the current collector, wherein the negative electrode material is the silica composite material according to any one of claims 1 to 7 and the silica composite material prepared by the method according to any one of claims 8 to 14.
16. A lithium battery comprising a positive electrode and a negative electrode, wherein the negative electrode comprises a current collector and a negative electrode material coated on the current collector, and the negative electrode material is the silica composite material according to any one of claims 1 to 7 and the silica composite material prepared by the method according to any one of claims 8 to 14.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010345671.7A CN113644239B (en) | 2020-04-27 | 2020-04-27 | Silica composite material and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010345671.7A CN113644239B (en) | 2020-04-27 | 2020-04-27 | Silica composite material and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113644239A CN113644239A (en) | 2021-11-12 |
| CN113644239B true CN113644239B (en) | 2023-10-13 |
Family
ID=78415175
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010345671.7A Active CN113644239B (en) | 2020-04-27 | 2020-04-27 | Silica composite material and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113644239B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20230124422A (en) * | 2022-02-18 | 2023-08-25 | 삼성에스디아이 주식회사 | Negative active material for rechargeable lithium battery and rechargeable lithium battery including the same |
| CN115050952B (en) * | 2022-08-11 | 2023-03-14 | 溧阳天目先导电池材料科技有限公司 | Silica anode material and preparation method and application thereof |
| CN115117327B (en) * | 2022-08-25 | 2022-11-22 | 溧阳天目先导电池材料科技有限公司 | Low-expansion silicon-based composite material and preparation method and application thereof |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106848282A (en) * | 2017-01-26 | 2017-06-13 | 彭宪利 | A kind of negative electrode material for nonaqueous electrode secondary battery and its preparation method and application |
| CN107123790A (en) * | 2016-02-24 | 2017-09-01 | 宁波富理电池材料科技有限公司 | A kind of porous silicon-base composite negative pole material, preparation method and lithium ion battery |
| CN107342407A (en) * | 2017-06-26 | 2017-11-10 | 合肥国轩高科动力能源有限公司 | Porous carbon loaded mesoporous SiOx/C composite negative electrode material and preparation method thereof |
| CN109390577A (en) * | 2018-12-11 | 2019-02-26 | 桑德集团有限公司 | Si/SiO2/ C composite nano-fiber material and preparation method thereof and negative electrode material |
| CN110010861A (en) * | 2019-03-07 | 2019-07-12 | 南方科技大学 | Silicon-based composite material, preparation method thereof and lithium ion battery |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9991509B2 (en) * | 2012-11-30 | 2018-06-05 | Lg Chem, Ltd. | Anode active material including porous silicon oxide-carbon material composite and method of preparing the same |
-
2020
- 2020-04-27 CN CN202010345671.7A patent/CN113644239B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107123790A (en) * | 2016-02-24 | 2017-09-01 | 宁波富理电池材料科技有限公司 | A kind of porous silicon-base composite negative pole material, preparation method and lithium ion battery |
| CN106848282A (en) * | 2017-01-26 | 2017-06-13 | 彭宪利 | A kind of negative electrode material for nonaqueous electrode secondary battery and its preparation method and application |
| CN107342407A (en) * | 2017-06-26 | 2017-11-10 | 合肥国轩高科动力能源有限公司 | Porous carbon loaded mesoporous SiOx/C composite negative electrode material and preparation method thereof |
| CN109390577A (en) * | 2018-12-11 | 2019-02-26 | 桑德集团有限公司 | Si/SiO2/ C composite nano-fiber material and preparation method thereof and negative electrode material |
| CN110010861A (en) * | 2019-03-07 | 2019-07-12 | 南方科技大学 | Silicon-based composite material, preparation method thereof and lithium ion battery |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113644239A (en) | 2021-11-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113644239B (en) | Silica composite material and preparation method thereof | |
| JP6006789B2 (en) | battery | |
| CN103904335B (en) | A kind of lithium ion battery negative material | |
| CN111816854B (en) | Lithium ion battery | |
| CN111180714B (en) | Carbon/molybdenum dioxide/silicon/carbon composite material, battery cathode comprising same and lithium ion battery | |
| CN114122352B (en) | Silicon-carbon negative electrode material for porous carbon doped induced silicon deposition and preparation method thereof | |
| CN107611360B (en) | Silicon monoxide graphene composite nano material, preparation method thereof and application thereof in lithium ion battery | |
| CN112952035B (en) | Negative electrode and preparation method and application thereof | |
| Huang et al. | Impact of fe doping on performance of NaTi2 (PO4) 3/C anode for aqueous lithium ion battery | |
| WO2024031867A1 (en) | Nitrogen-doped graphene-coated silicon-carbon composite material, and preparation method therefor and use thereof | |
| CN105702958B (en) | Preparation method and application of tin dioxide quantum dot solution and composite material thereof | |
| CN115188938A (en) | Silicon cathode, preparation method of silicon cathode and battery thereof | |
| CN115799447A (en) | Positive plate, preparation method thereof and sodium ion battery | |
| CN115207263B (en) | Secondary battery | |
| CN106848282B (en) | Negative electrode material for non-aqueous electrolyte secondary battery and preparation method and application thereof | |
| Wei et al. | Nanostructured SiOx/Si composite confined by carbon layer as anode materials for high-performance lithium-ion battery | |
| CN111313012A (en) | Multiwalled carbon nanotube graphite lithium ion battery negative electrode material and preparation method thereof | |
| EP4273966A1 (en) | Silicon-doped graphene composite material, preparation method for same, and applications thereof | |
| CN111628150B (en) | Carbon-coated lithium sulfide composite electrode for lithium-sulfur battery and preparation method thereof | |
| CN112786834A (en) | Positive pole piece and lithium ion battery comprising same | |
| CN111564616A (en) | AgNWs @ Si @ GO lithium ion battery cathode material, preparation method thereof and lithium ion battery adopting same | |
| CN103427119B (en) | Battery with a battery cell | |
| CN115172680A (en) | High-capacity high-rate lithium ion battery and preparation method thereof | |
| CN113381023A (en) | Flexible self-supporting FeF3Preparation method of/C-graphene composite membrane positive electrode material | |
| CN112186158A (en) | Positive electrode composite material and preparation method and application thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |