CN114105133A - Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof - Google Patents
Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof Download PDFInfo
- Publication number
- CN114105133A CN114105133A CN202111216321.1A CN202111216321A CN114105133A CN 114105133 A CN114105133 A CN 114105133A CN 202111216321 A CN202111216321 A CN 202111216321A CN 114105133 A CN114105133 A CN 114105133A
- Authority
- CN
- China
- Prior art keywords
- silicon
- graphite
- silicon oxide
- composite material
- carbon composite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- 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
- H01M4/366—Composites as layered products
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/05—Accumulators with non-aqueous electrolyte
- H01M10/052—Li-accumulators
- H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
- H01M4/386—Silicon or alloys based on silicon
-
- 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
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/80—Particles consisting of a mixture of two or more inorganic phases
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/40—Electric properties
-
- 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 discloses a graphite-silicon/silicon oxide-carbon composite material and a preparation method and application thereof. Carrying out ball milling treatment on graphite powder and nano silicon to obtain graphite-silicon/silicon oxide composite particles; dispersing the graphite-silicon/silicon oxide composite particles into an organic solvent, adding asphalt, heating, stirring and mixing to obtain a graphite-silicon/silicon oxide-asphalt composite material; the graphite-silicon/silicon oxide-asphalt composite material is subjected to pyrolysis treatment to obtain the graphite-silicon/silicon oxide-carbon composite material, the composite material is used as a negative electrode material for lithium ion, the obtained lithium ion battery has the characteristics of high discharge specific capacity, good charge and discharge performance, high cycle stability and the like, and the raw materials adopted in the preparation process of the composite material are cheap, the process flow is simple, the implementation is easy, and the composite material is suitable for large-scale production.
Description
Technical Field
The invention relates to a lithium ion battery cathode material, in particular to a graphite-silicon/silicon oxide-carbon composite material, a preparation method thereof and application of the composite material as the lithium ion battery cathode material; belongs to the technical field of lithium ion batteries.
Background
With the continuous updating and iteration of products such as electric automobiles, wearable electronic equipment, energy storage equipment and the like, the enthusiasm of consumers to the products is continuously increased, the market demand for energy storage devices is also more and more urgent and harsh, the lithium ion battery is taken as the most widely applied secondary battery at present, but the existing factors such as capacity, rate capability, safety, cycle performance and the like do not completely meet the demand of higher markets, the conditions are improved, and the development of a novel lithium ion battery cathode material is a key. The theoretical capacity of the traditional graphite cathode is only 372mAh/g, and the development of the whole lithium ion battery industry is severely restricted. The silicon (Si) cathode material has high theoretical capacity and low discharge platform (0.3-0.5V vs. Li/Li)+) Rich resources, good safety performance and the like, the theoretical capacity of the material can reach 4200mAh/g, and the material is an electrode material which is possible to replace a commercial graphite cathode. Therefore, silicon-based materials are receiving more and more attention from researchers as negative electrodes of lithium ion batteries.
However, Si negative electrode materials also face many problems during charging and discharging: 1) the material is pulverized, the material can generate huge volume expansion in the charging and discharging processes, so that the internal stress of the material is increased, the material can be separated from a current collector when the internal stress of the material exceeds a certain limit, Si particles separated from the current collector can lose the electrochemical activity of the Si particles and cannot participate in the alloying reaction of lithium ions in a battery, and the cycle performance of the material is further causedA rapid decay. 2) Repeated growth of SEI film when the voltage of the cathode material is less than 1V (vs. Li/Li)+) In the cycle process of the lithium ion battery, a layer of electrolyte interface (SEI) which only allows ions but not electrons to pass is formed on the surface of the electrode material, and the SEI effectively prevents the electrolyte from being further decomposed, thereby playing a great role in ensuring that the Si material has long cycle performance. However, when the Si material is discharged, the SEI film is formed on the surface of the material by volume expansion of the material as lithium is alloyed with Si, and when lithium is dealloyed with Si, the SEI film on the surface of the material is destroyed by volume contraction. Such repetition causes repeated formation of an SEI film, thereby causing a large consumption of lithium ions and an electrolyte solution, and reducing the coulombic efficiency and cycle performance of the material. 3) The electrode is difficult to design, and because the Si negative electrode material is accompanied by the huge change of the volume in the charging and discharging process, the active substance is separated from the current collector, so that a large amount of materials are inactivated in the charging and discharging process, and the volume of the negative electrode is changed in the whole process, the characteristics of the Si negative electrode material should be considered in the design process of the full battery, so that the design difficulty of the battery negative electrode is increased. In addition, the Si cathode material has the characteristic of low conductivity, and the Si cathode material belongs to a semiconductor material and has the conductivity of only 10 at room temperature-5–10-3S cm-1, lithium ion diffusion rate of only 10-14-10-13cm2 s-1Resulting in lower rate performance of the material. In view of the above problems, researchers have searched for various methods for improving the cycle performance of silicon negative electrode materials, such as reducing the particle size of silicon particles, designing a special structure, performing carbon coating, improving a binder, and the like. The method is more effective in preparing the silicon-based composite material to relieve the volume expansion in the charging and discharging processes, and the method is widely applied to the modification research of the lithium ion battery cathode material.
Chinese patent (CN108565451A) discloses a preparation method of a silicon-carbon negative electrode material: amorphous carbon and graphite are adopted to coat silicon particles, so that the conductivity of the battery material and the cycle performance of the battery are improved, but the method cannot well relieve the volume expansion of the nano silicon in the discharging process.
Chinese patent (CN106941164A) discloses a preparation method of a silicon-carbon negative electrode core-shell material, which comprises the following steps: amorphous carbon and graphene are adopted to coat silicon particles, so that the conductivity of a battery material and the cycle performance of a battery are improved to a certain extent, but the method cannot well protect pulverization of nano silicon particles and falling of active substances under the condition of high cycle times.
The method can not well solve the problem of rapid expansion of the volume of the silicon material in the charging and discharging processes.
Disclosure of Invention
Aiming at the defects in the prior art, the first object of the invention is to provide a graphite-silicon/silicon oxide-carbon composite material, which has a core-shell structure, wherein the pyrolytic carbon layer is a shell layer, the graphite-silicon/silicon oxide composite particles form an inner core, the shell layer is the pyrolytic carbon layer, the electrical conductivity of the silicon material can be effectively improved, the volume change of the nano silicon material in the charging and discharging process can be buffered, the inner core takes the graphite particles as a framework, the silicon oxide is loaded on the surface of the framework to coat the silicon nano particles, the graphite particles have high electrical conductivity, the volume expansion of the nano silicon material in the discharging process can be buffered together inside and outside by matching with the pyrolytic carbon layer, and the silicon oxide layer on the surface of the nano silicon can generate Li in the charging and discharging process4SiO4The volume expansion of the nano silicon in the discharging process can be well buffered, so that the problem of rapid volume expansion of the silicon material cathode in the discharging process can be fundamentally solved, the charging and discharging performance of the silicon cathode lithium ion battery can be improved, and the service life of the silicon cathode lithium ion battery can be prolonged.
The second purpose of the invention is to provide a preparation method of the graphite-silicon/silicon oxide-carbon composite material, which has the advantages of simple operation, low raw material cost and contribution to large-scale production.
The third purpose of the invention is to provide an application of the graphite-silicon/silicon oxide-carbon composite material, and the application of the graphite-silicon/silicon oxide-carbon composite material as a negative electrode material of a lithium ion battery can obtain the lithium ion battery with high specific capacity and good cycle performance.
In order to achieve the technical purpose, the invention provides a preparation method of a graphite-silicon/silicon oxide-carbon composite material, which comprises the following steps:
1) carrying out ball milling treatment on graphite powder and nano silicon to obtain graphite-silicon/silicon oxide composite particles;
2) dispersing the graphite-silicon/silicon oxide composite particles into an organic solvent, adding asphalt, heating, stirring and mixing to obtain a graphite-silicon/silicon oxide-asphalt composite material;
3) and carrying out pyrolysis treatment on the graphite-silicon/silicon oxide-asphalt composite material to obtain the graphite-silicon/silicon oxide-carbon composite material.
Firstly, ball milling treatment is carried out on graphite powder and nano-silicon, in the ball milling process, on one hand, nano-silicon particles can be uniformly adhered to the surfaces of the graphite particles to form composite particles taking the graphite particles as a framework, and the surfaces of the graphite particles adsorb the nano-silicon, on the other hand, in the ball milling process, mechanical ball milling energy and oxygen in the air are utilized to oxidize the surfaces of the nano-silicon, a layer of thin silicon oxide is generated on the surfaces of the nano-silicon, so that graphite-silicon/silicon oxide composite particles are formed, then, asphalt is further utilized as a carbon source to carry out carbon coating on the graphite-silicon/silicon oxide particles, and finally, the graphite-silicon/silicon oxide-carbon composite material with a special structure is formed, the inner graphite particle framework and the outer pyrolytic carbon coating layer of the composite material not only can greatly improve the conductivity of the silicon material, and the volume expansion of nano silicon in the discharge process is buffered together inside and outside, the stability is improved, and a silicon oxide layer generated on the surface of the nano silicon can generate Li in the charge and discharge processes4SiO4And the like, which can well buffer the volume expansion of the nano silicon in the discharge process.
As a preferable scheme, the particle size range of the graphite powder is 0.3-8 μm; the particle size range of the nano silicon is 10 nm-200 nm. The graphite powder selected by the preferred scheme has micron-sized particles, and the nano-silicon is nano-sized particles, so that the composite particle material which takes the graphite particles as the framework surface and adsorbs the silicon nano-particles is formed in the ball milling process.
Preferably, the mass ratio of the graphite powder to the nano silicon is 0.5-10: 1. More preferably 0.5 to 5: 1.
As a preferred scheme, the conditions of the ball milling treatment are as follows: the rotating speed is 300-1200 rad/s, the ball-material ratio is 5-25: 1, and the ball milling time is 0.5-6 h. The ball milling process is carried out in a conventional air atmosphere. Under the optimal ball milling condition, the nano silicon particles can be uniformly adhered to the surfaces of the graphite particles, and the surface oxidation of the nano silicon can be promoted by utilizing the mechanical ball milling, so that a layer of thin silicon oxide is generated on the surfaces of the nano silicon. The thickness of the silicon oxide layer is generally 2 to 10 nm. The ball milling rotation speed is further preferably 500 to 1000 rad/s. The ball-to-feed ratio is more preferably 6 to 18: 1. The ball milling time is further preferably 1 to 3 hours. If the ball milling is not carried out but only the simple mechanical mixing is carried out, a layer of silicon oxide cannot be generated on the surface of the nano silicon, and the nano silicon particles are difficult to be uniformly adhered to the surface of the graphite particles, so that the composite material of the invention cannot be formed.
Preferably, the mass ratio of the graphite-silicon/silicon oxide composite particles to the organic solvent is 1: 50-600. The organic solvent is a common organic solvent capable of dissolving and dispersing asphalt, and is preferably cheap absolute ethyl alcohol. The mass ratio of the graphite-silicon/silicon oxide composite particles to the organic solvent is more preferably 1:200 to 300.
As a preferable scheme, the adding amount of the asphalt is 0.4-4 times of the mass of the graphite-silicon/silicon oxide composite particles. The addition amount of the asphalt is more preferably 1-3 times of the mass of the graphite-silicon/silicon oxide composite particles. The addition of the asphalt mainly affects the thickness of the carbon coating layer, the uniform carbon coating layer is difficult to form on the surface of the silicon material due to the too small addition of the asphalt, and the electrochemical performance of the composite material is also affected due to the too thick carbon coating layer.
As a preferable mode, the heating and stirring conditions are as follows: the temperature is 50-150 ℃, the stirring speed is 100-500 r/min, and the stirring time is 10-150 min. Under the optimal conditions, the asphalt can be promoted to be dissolved and dispersed, and is uniformly adsorbed on the surface of the graphite-silicon/silicon oxide composite particles, thereby being beneficial to the generation of the carbon coating. The temperature is more preferably 50 to 150 ℃. The stirring rate is further 200 to 300 r/min. The stirring time is further preferably 30 to 120 min.
As a preferred embodiment, the pyrolysis treatment conditions are: the temperature is 500-950 ℃, and the time is 0.5-5 h; the atmosphere is an inert atmosphere. The temperature is more preferably 550 to 800 ℃. The time is further preferably 0.5h to 3 h; the inert atmosphere is one of nitrogen, argon or helium. If the pyrolysis temperature is too low, the asphalt is not pyrolyzed completely, and if the pyrolysis temperature is too high, carbothermic reduction is likely to occur, and part of the silicon oxide is reduced into silicon.
The invention also provides a graphite-silicon/silicon oxide-carbon composite material which is prepared by the preparation method.
The graphite-silicon/silicon oxide-carbon composite material has a core-shell structure, a pyrolytic carbon layer is taken as a shell layer, graphite-silicon/silicon oxide composite particles form a core, the shell layer is the pyrolytic carbon layer, the electrical conductivity of the silicon material can be effectively improved, the volume change of the nano silicon material in the charging and discharging process can be buffered, the core takes graphite particles as a framework, silicon oxide is loaded on the surface of the framework to coat silicon nanoparticles, the graphite particles have high electrical conductivity, the pyrolytic carbon layer can be matched to realize that the volume expansion of the nano silicon material in the discharging process is buffered inside and outside, and the silicon oxide layer on the surface of the nano silicon can generate Li in the charging and discharging process4SiO4The volume expansion of the nano silicon in the discharging process can be well buffered, so that the problem of rapid volume expansion of the silicon material cathode in the discharging process can be fundamentally solved, the charging and discharging performance of the silicon cathode lithium ion battery can be improved, and the service life of the silicon cathode lithium ion battery can be prolonged.
The invention provides an application of a graphite-silicon/silicon oxide-carbon composite material, which is applied as a lithium ion battery cathode material.
The graphite-silicon/silicon oxide-carbon composite material is used for a lithium ion battery: bonding graphite-silicon/silicon oxide-carbon compositesThe agent and the conductive agent are uniformly mixed, coated on a copper foil, dried in a drying oven at 80 ℃, and sliced to form the electrode slice. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell.
Compared with the prior art, the technical scheme of the invention has the following beneficial effects:
1) the graphite-silicon/silicon oxide-carbon composite material provided by the invention has a special core-shell structure, a pyrolytic carbon layer is taken as a shell layer, and graphite-silicon/silicon oxide composite particles form an inner core, the shell layer is the pyrolytic carbon layer, so that the electrical conductivity of a silicon material can be effectively improved, and the volume change of the nano silicon material in the charging and discharging process can be buffered, the inner core takes graphite particles as a framework, silicon oxide is loaded on the surface of the framework to coat silicon nano particles, the graphite particles have high electrical conductivity, and the pyrolytic carbon layer can be matched to realize that the volume expansion of the nano silicon material in the discharging process is buffered together inside and outside, and the silicon oxide layer on the surface of the nano silicon can generate Li in the charging and discharging process4SiO4The volume expansion of the nano silicon in the discharging process can be well buffered, so that the problem of rapid volume expansion of the silicon material cathode in the discharging process can be fundamentally solved, the charging and discharging performance of the silicon cathode lithium ion battery can be improved, and the service life of the silicon cathode lithium ion battery can be prolonged.
2) The graphite-silicon/silicon oxide-carbon composite material provided by the invention is used as a negative electrode material to be assembled into a lithium ion battery, the specific discharge capacity of the first circle is 1046.3mAh/g under the current density of 1A/g within the voltage range of 0.01-1V, after 200 circles of circulation, the specific discharge capacity can reach 938.5mAh/g, the coulombic efficiency is basically kept above 99% in the circulation process, and the composite material is proved to have stable structure and good charge and discharge performance.
3) The preparation method of the graphite-silicon/silicon oxide-carbon composite material provided by the invention has the advantages of relatively low price of raw materials, simple process and suitability for industrial production.
Drawings
Fig. 1 is an SEM electron micrograph of the graphite-silicon/silicon oxide-carbon composite prepared in example 1 of the present invention.
Fig. 2 is an SEM electron micrograph of the graphite-silicon/silicon oxide composite particles prepared in example 1 of the present invention.
Fig. 3 is an HRTEM of a graphite-silicon/silicon oxide-carbon composite prepared in example 1 of the present invention.
Fig. 4 is a cycle performance curve of the graphite-silicon/silicon oxide-carbon composite anode material prepared in example 1 of the present invention at a current density of 1A/g.
Detailed Description
While the following is a description of the preferred embodiments of the present invention, it should be noted that those skilled in the art can make various modifications and improvements without departing from the principle of the embodiments of the present invention, and such modifications and improvements are considered to be within the scope of the embodiments of the present invention.
Graphite powder and nano-silicon in the following examples are used as commercial raw materials, the particle size range of the graphite powder is 0.3-8 μm, and the particle size range of the nano-silicon is 10-200 nm.
Example 1
Placing 5g of graphite and 5g of nano-silicon in a ball mill for ball milling at the rotating speed of 800rad/s, the ball-material ratio of 10:1 (mass ratio) and the ball milling time of 3h to synthesize graphite-silicon/silicon oxide composite particles; putting 1g of graphite-silicon/silicon oxide composite particles into 300ml of absolute ethyl alcohol, and adding 1.5g of asphalt into the absolute ethyl alcohol to form a mixed solution; placing the mixed solution in a magnetic stirrer at 85 ℃, stirring at the speed of 200r/min for 90min to obtain a graphite-silicon/silicon oxide-asphalt composite material; and carrying out high-temperature heat treatment on the obtained graphite-silicon/silicon oxide-asphalt composite material at 750 ℃ in an argon atmosphere for 2h to obtain the graphite-silicon/silicon oxide-carbon composite negative electrode material. In an SEM electron microscope image of the graphite-silicon/silicon oxide composite particle obtained in this example, as shown in fig. 2, it can be observed that the nano silicon particles are well adsorbed on the surface of the graphite particles; FIG. 1 shows graphite-silicon-According to SEM (scanning electron microscope) images of the silicon oxide-carbon composite cathode material, the nano silicon particles are not only well adsorbed on the surfaces of graphite particles, and a layer of complete amorphous carbon is coated on the surfaces of the materials, the materials take graphite as a framework, the surfaces of the particles are coated with carbon, and the volume expansion of the nano silicon in the discharge process is buffered by adopting the inner and outer parts together, so that the electrochemical performance of the materials is improved; FIG. 3 is an HRTEM image of the graphite-silicon/silicon oxide-carbon composite anode material prepared in this example, wherein it can be seen that a thin silicon oxide layer is formed on the surface of the nano-silicon, and Li is formed on the silicon oxide layer during the charge and discharge processes4SiO4And the like, so that the volume expansion of the nano silicon in the discharge process can be further buffered, and the cycle performance of the material is improved.
Assembling the battery: uniformly mixing the graphite-silicon/silicon oxide-carbon composite negative electrode material with sodium carboxymethylcellulose and Super P according to the mass ratio of 8:1:1, coating the mixture on a copper foil to form a composite material with consistent thickness, drying the composite material in a drying box at the temperature of 80 ℃, and slicing the composite material to form the electrode plate. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell. And testing the charge and discharge performance of the battery within the voltage range of 0.01-1V. The cycle performance curve of the graphite-silicon/silicon oxide-carbon composite anode material, as shown in FIG. 4, is at 1A g-1Under the circulating current, the specific discharge capacity of the first circle reaches 1046.3mAh/g, after the circulation is carried out for 200 circles, the specific discharge capacity can reach 938.5mAh/g, and the coulombic efficiency is basically kept above 99% in the circulating process, which shows that the material has stable structure and good charging and discharging performance.
Example 2
Placing 5g of graphite and 10g of nano-silicon into a ball mill for ball milling at the rotating speed of 800rad/s, the ball-material ratio of 10:1 and the ball milling time of 3h to synthesize graphite-silicon/silicon oxide composite particles; putting 1g of graphite-silicon/silicon oxide composite particles into 300ml of absolute ethyl alcohol, and adding 0.67g of asphalt into the absolute ethyl alcohol to form a mixed solution; placing the mixed solution in a magnetic stirrer at 60 ℃, stirring at the speed of 200r/min for 20min to obtain a graphite-silicon/silicon oxide-asphalt composite material; and carrying out high-temperature heat treatment on the obtained graphite-silicon/silicon oxide-asphalt composite material at 600 ℃ in an argon atmosphere for 2h to obtain the graphite-silicon/silicon oxide-carbon composite negative electrode material. In the graphite-silicon/silicon oxide composite particles obtained in this embodiment, the nano-silicon particles can be well adsorbed on the surface of the graphite particles, and the amorphous carbon coated on the surface of the material is thin and incomplete.
Assembling the battery: the graphite-silicon/silicon oxide-carbon composite negative electrode material, sodium carboxymethylcellulose and Super P are uniformly mixed according to the mass ratio of 8:1:1, then the mixture is coated on a copper foil to form a composite material with consistent thickness, and the composite material is dried in a drying box at the temperature of 80 ℃ and sliced to form an electrode plate. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell. And testing the charge and discharge performance of the battery within the voltage range of 0.01-1V. The cycle performance curve of the graphite-silicon/silicon oxide-carbon composite negative electrode material shows that the first-turn specific discharge capacity is 1865.7mAh/g under the current density of 1A/g, after 200 cycles, the specific discharge capacity is still 569.5mAh/g, and the coulombic efficiency is basically kept above 99% in the cycle process, which indicates that the structural stability of the composite material is general.
Example 3
Placing 3g of graphite and 1g of nano-silicon in a ball mill for ball milling at the rotating speed of 800rad/s, the ball-material ratio of 15:1 and the ball milling time of 4h to synthesize graphite-silicon/silicon oxide composite particles; putting 1g of graphite-silicon/silicon oxide composite particles into 300ml of absolute ethyl alcohol, and adding 2g of asphalt into the absolute ethyl alcohol to form a mixed solution; placing the mixed solution in a magnetic stirrer at 100 ℃, stirring at the speed of 300r/min for 150min to obtain a graphite-silicon/silicon oxide-asphalt composite material; and carrying out high-temperature heat treatment on the obtained graphite-silicon/silicon oxide-asphalt composite material at 800 ℃ for 3h in an argon atmosphere to obtain the graphite-silicon/silicon oxide-carbon composite negative electrode material. In the graphite-silicon/silicon oxide composite particles obtained in the embodiment, nano silicon particles can be well adsorbed on the surfaces of graphite particles, and the amorphous carbon coating on the surfaces of the graphite particles is relatively complete.
Assembling the battery: the graphite-silicon/silicon oxide-carbon composite negative electrode material, sodium carboxymethylcellulose and Super P are uniformly mixed according to the mass ratio of 8:1:1, then the mixture is coated on a copper foil to form a composite material with consistent thickness, and the composite material is dried in a drying box at 120 ℃ and sliced to form an electrode plate. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell. And testing the charge and discharge performance of the battery within the voltage range of 0.01-1V. According to a cycle performance curve of the graphite-silicon/silicon oxide-carbon composite negative electrode material, under the current density of 1A/g, the first-turn specific discharge capacity is 679.1mAh/g, after 200 cycles, the specific discharge capacity is still 420.6mAh/g, and the coulombic efficiency is basically kept above 99% in the cycle process, so that the structural stability of the composite material is better.
Example 4 (comparative example)
Placing 5g of graphite and 10g of nano-silicon into a ball mill for ball milling at the rotating speed of 800rad/s, the ball-material ratio of 10:1 and the ball milling time of 3h to synthesize graphite-silicon/silicon oxide composite particles; putting 1g of graphite-silicon/silicon oxide composite particles into 300ml of absolute ethyl alcohol, and adding 0.1g of asphalt into the absolute ethyl alcohol to form a mixed solution; placing the mixed solution in a magnetic stirrer at 100 ℃, stirring at the speed of 200r/min for 150min to obtain a graphite-silicon/silicon oxide-asphalt composite material; and carrying out high-temperature heat treatment on the obtained graphite-silicon/silicon oxide-asphalt composite material at 600 ℃ in an argon atmosphere for 2h to obtain the graphite-silicon/silicon oxide-carbon composite negative electrode material. In the graphite-silicon/silicon oxide composite particles obtained in the embodiment, the nano silicon particles can be better adsorbed on the surfaces of the graphite particles, and the amorphous carbon on the surfaces of the graphite particles is coated, so that the integrity of the formed amorphous carbon is lower due to the fact that the amount of asphalt is less and the heat treatment temperature is lower.
Assembling the battery: the graphite-silicon/silicon oxide-carbon composite negative electrode material, sodium carboxymethylcellulose and Super P are uniformly mixed according to the mass ratio of 8:1:1, then the mixture is coated on a copper foil to form a composite material with consistent thickness, and the composite material is dried in a drying box at 120 ℃ and sliced to form an electrode plate. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell. And testing the charge and discharge performance of the battery within the voltage range of 0.01-1V. According to a cycle performance curve of the graphite-silicon/silicon oxide-carbon composite negative electrode material, under the current density of 1A/g, the first-turn specific discharge capacity is 1453.6mAh/g, after 200-turn circulation, only 486.6mAh/g of specific discharge capacity remains, although the first-turn specific discharge capacity is higher, the coulomb efficiency is poorer in the cycle process.
Example 5 (comparative example)
Placing 5g of graphite and 5g of nano-silicon in a ball mill for ball milling at the rotating speed of 800rad/s, the ball-material ratio of 10:1 and the ball milling time of 3h to synthesize graphite-silicon/silicon oxide composite particles; putting 1g of graphite-silicon/silicon oxide composite particles into 300ml of absolute ethyl alcohol, and adding 5g of asphalt into the absolute ethyl alcohol to form a mixed solution; placing the mixed solution in a magnetic stirrer at 100 ℃, stirring at the speed of 200r/min for 150min to obtain a graphite-silicon/silicon oxide-asphalt composite material; and carrying out high-temperature heat treatment on the obtained graphite-silicon/silicon oxide-asphalt composite material for 3h at 750 ℃ in an argon atmosphere to obtain the graphite-silicon/silicon oxide-carbon composite negative electrode material. In the graphite-silicon/silicon oxide composite particles obtained in the embodiment, nano silicon particles can be well adsorbed on the surfaces of graphite particles, and thick amorphous carbon coatings are formed on the surfaces of the graphite particles.
Assembling the battery: the graphite-silicon/silicon oxide-carbon composite negative electrodeThe electrode material, sodium carboxymethyl cellulose and Super P are uniformly mixed according to the mass ratio of 8:1:1, then the mixture is coated on a copper foil to form a composite material with consistent thickness, and the composite material is dried in a drying oven at 120 ℃ and sliced to form the electrode slice. In a sealed glove box filled with argon, an electrode plate loaded with active materials is taken as a working electrode, a microporous polypropylene membrane is taken as a diaphragm, and 1.0M LiPF6The mixed solvent of Ethylene Carbonate (EC) and dimethyl carbonate (DMC) which are dissolved in the volume ratio of 1:1 and 5 percent of VC is taken as electrolyte, and a metal lithium sheet is taken as a counter electrode to assemble the CR2025 button cell. And testing the charge and discharge performance of the battery within the voltage range of 0.01-1V. According to a cycle performance curve of the graphite-silicon/silicon oxide-carbon composite negative electrode material, under the current density of 1A/g, the first circle of discharge specific capacity is 635.1mAh/g, after 200 circles of circulation, the discharge specific capacity is still 386.9mAh/g, the coulombic efficiency is lower in the cycle process, the surface amorphous coated carbon layer of the material is thicker due to more asphalt adding amount, more holes can be generated on the thick amorphous carbon layer, the conductivity is lower than normal, and the first specific capacity and the coulombic efficiency are lower.
Claims (10)
1. A preparation method of a graphite-silicon/silicon oxide-carbon composite material is characterized by comprising the following steps: the method comprises the following steps:
1) carrying out ball milling treatment on graphite powder and nano silicon to obtain graphite-silicon/silicon oxide composite particles;
2) dispersing the graphite-silicon/silicon oxide composite particles into an organic solvent, adding asphalt, heating, stirring and mixing to obtain a graphite-silicon/silicon oxide-asphalt composite material;
3) and carrying out pyrolysis treatment on the graphite-silicon/silicon oxide-asphalt composite material to obtain the graphite-silicon/silicon oxide-carbon composite material.
2. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the particle size range of the graphite powder is 0.3-8 mu m; the particle size range of the nano silicon is 10 nm-200 nm.
3. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the mass ratio of the graphite powder to the nano silicon is 0.5-10: 1.
4. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the ball milling treatment conditions are as follows: the rotating speed is 300-1200 rad/s, the ball-to-material ratio is 5-25: 1, the ball milling time is 0.5-6 h.
5. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the mass ratio of the graphite-silicon/silicon oxide composite particles to the organic solvent is 1: 50-600; the organic solvent is absolute ethyl alcohol.
6. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the addition amount of the asphalt is 0.5-4 times of the mass of the graphite-silicon/silicon oxide composite particles.
7. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the heating and stirring conditions are as follows: the temperature is 50-150 ℃, the stirring speed is 100-500 r/min, and the stirring time is 10-150 min.
8. The method for preparing a graphite-silicon/silicon oxide-carbon composite material according to claim 1, wherein: the pyrolysis treatment conditions are as follows: the temperature is 500-950 ℃, and the time is 0.5-5 h; the atmosphere is an inert atmosphere.
9. A graphite-silicon/silicon oxide-carbon composite material, characterized in that: the preparation method of any one of claims 1 to 8.
10. The use of a graphite-silicon/silicon oxide-carbon composite according to claim 9, wherein:
the material is applied as a negative electrode material of a lithium ion battery.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111216321.1A CN114105133B (en) | 2021-10-19 | 2021-10-19 | Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111216321.1A CN114105133B (en) | 2021-10-19 | 2021-10-19 | Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114105133A true CN114105133A (en) | 2022-03-01 |
| CN114105133B CN114105133B (en) | 2023-09-05 |
Family
ID=80376483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111216321.1A Active CN114105133B (en) | 2021-10-19 | 2021-10-19 | Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114105133B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115020684A (en) * | 2022-07-26 | 2022-09-06 | 蜂巢能源科技股份有限公司 | Graphite, silicon oxide and silicon composite negative electrode material and application thereof |
Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008025188A1 (en) * | 2006-08-22 | 2008-03-06 | Btr Energy Materials Co., Ltd. | A silicon-carbon composite negative material for lithium ion battery and the preparation method of the same |
| US20100009261A1 (en) * | 2008-07-14 | 2010-01-14 | Koichiro Watanabe | Negative electrode material, making method, lithium ion secondary battery, and electrochemical capacitor |
| WO2013067956A1 (en) * | 2011-11-10 | 2013-05-16 | 北京有色金属研究总院 | Nano-silicon/carbon composite material and preparation method therefor |
| CN103730644A (en) * | 2013-12-12 | 2014-04-16 | 天津巴莫科技股份有限公司 | Preparation method of silicon-silicon oxide-carbon composite negative pole material of lithium ion battery |
| CN104466141A (en) * | 2013-09-17 | 2015-03-25 | 北京有色金属研究总院 | Preparation method of Si / graphite / C composite material for lithium ion battery |
| JP2015106563A (en) * | 2013-11-29 | 2015-06-08 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | SIOx BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL, PREPARATION METHOD AND BATTERY |
| JP2015118911A (en) * | 2013-12-19 | 2015-06-25 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | Silicon-based composite negative electrode material for lithium ion secondary batteries, manufacturing method, and battery |
| US20160211511A1 (en) * | 2015-01-20 | 2016-07-21 | Shenzhen Btr New Energy Materials Inc. | Nano-silicon composite negative electrode material used for lithium ion battery, process for preparing the same and lithium ion battery |
| WO2017008494A1 (en) * | 2015-07-10 | 2017-01-19 | 田东 | Method for fabricating graphite silicon-based composite negative-electrode material |
| CN106935836A (en) * | 2017-04-26 | 2017-07-07 | 宁夏博尔特科技有限公司 | Lithium ion battery Si oxide and carbon compound cathode materials and preparation method thereof |
| WO2018032974A1 (en) * | 2016-08-15 | 2018-02-22 | 福建新峰二维材料科技有限公司 | Method of preparing material of negative electrode of lithium ion battery |
| CN110085842A (en) * | 2019-05-10 | 2019-08-02 | 山西大学 | A kind of silicon-carbon composite cathode material and preparation method thereof |
| KR20190142177A (en) * | 2018-06-15 | 2019-12-26 | 주식회사 테라테크노스 | Method to manufacture silicon oxide cathode material of lithium battery |
| WO2020107672A1 (en) * | 2018-11-27 | 2020-06-04 | 广州汽车集团股份有限公司 | Silicon-based composite negative electrode material and preparation method thereof, and negative electrode of lithium ion battery |
| CN111755678A (en) * | 2020-07-06 | 2020-10-09 | 马鞍山科达普锐能源科技有限公司 | Silicon-carbon negative electrode material for lithium ion battery and preparation method thereof |
-
2021
- 2021-10-19 CN CN202111216321.1A patent/CN114105133B/en active Active
Patent Citations (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2008025188A1 (en) * | 2006-08-22 | 2008-03-06 | Btr Energy Materials Co., Ltd. | A silicon-carbon composite negative material for lithium ion battery and the preparation method of the same |
| US20100009261A1 (en) * | 2008-07-14 | 2010-01-14 | Koichiro Watanabe | Negative electrode material, making method, lithium ion secondary battery, and electrochemical capacitor |
| WO2013067956A1 (en) * | 2011-11-10 | 2013-05-16 | 北京有色金属研究总院 | Nano-silicon/carbon composite material and preparation method therefor |
| CN104466141A (en) * | 2013-09-17 | 2015-03-25 | 北京有色金属研究总院 | Preparation method of Si / graphite / C composite material for lithium ion battery |
| JP2015106563A (en) * | 2013-11-29 | 2015-06-08 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | SIOx BASED COMPOSITE NEGATIVE ELECTRODE MATERIAL, PREPARATION METHOD AND BATTERY |
| CN103730644A (en) * | 2013-12-12 | 2014-04-16 | 天津巴莫科技股份有限公司 | Preparation method of silicon-silicon oxide-carbon composite negative pole material of lithium ion battery |
| JP2015118911A (en) * | 2013-12-19 | 2015-06-25 | 深▲セン▼市貝特瑞新能源材料股▲ふん▼有限公司 | Silicon-based composite negative electrode material for lithium ion secondary batteries, manufacturing method, and battery |
| US20160211511A1 (en) * | 2015-01-20 | 2016-07-21 | Shenzhen Btr New Energy Materials Inc. | Nano-silicon composite negative electrode material used for lithium ion battery, process for preparing the same and lithium ion battery |
| WO2017008494A1 (en) * | 2015-07-10 | 2017-01-19 | 田东 | Method for fabricating graphite silicon-based composite negative-electrode material |
| WO2018032974A1 (en) * | 2016-08-15 | 2018-02-22 | 福建新峰二维材料科技有限公司 | Method of preparing material of negative electrode of lithium ion battery |
| CN106935836A (en) * | 2017-04-26 | 2017-07-07 | 宁夏博尔特科技有限公司 | Lithium ion battery Si oxide and carbon compound cathode materials and preparation method thereof |
| KR20190142177A (en) * | 2018-06-15 | 2019-12-26 | 주식회사 테라테크노스 | Method to manufacture silicon oxide cathode material of lithium battery |
| WO2020107672A1 (en) * | 2018-11-27 | 2020-06-04 | 广州汽车集团股份有限公司 | Silicon-based composite negative electrode material and preparation method thereof, and negative electrode of lithium ion battery |
| CN110085842A (en) * | 2019-05-10 | 2019-08-02 | 山西大学 | A kind of silicon-carbon composite cathode material and preparation method thereof |
| CN111755678A (en) * | 2020-07-06 | 2020-10-09 | 马鞍山科达普锐能源科技有限公司 | Silicon-carbon negative electrode material for lithium ion battery and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 李媛媛;满意;林荣英;洪若瑜;: "锂离子电池碳包硅/石墨复合材料的制备及其电化学性能研究", 化工新型材料, no. 06 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115020684A (en) * | 2022-07-26 | 2022-09-06 | 蜂巢能源科技股份有限公司 | Graphite, silicon oxide and silicon composite negative electrode material and application thereof |
| CN115020684B (en) * | 2022-07-26 | 2023-10-20 | 蜂巢能源科技股份有限公司 | Graphite, silicon oxide and silicon composite negative electrode material and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114105133B (en) | 2023-09-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107507972B (en) | Preparation method of silicon-carbon negative electrode material, silicon-carbon negative electrode material and lithium ion battery | |
| CN107611406B (en) | Preparation method of silicon/graphene/carbon composite negative electrode material | |
| CN106784707B (en) | A kind of preparation method of nano-silicon-carbon composition lithium ion battery cathode material | |
| CN110620224A (en) | Negative electrode material for lithium battery, preparation method of negative electrode material and lithium battery | |
| CN106935860A (en) | A kind of carbon intercalation V2O3Nano material, its preparation method and application | |
| CN108682820B (en) | Silicon-carbon composite negative electrode material, negative electrode plate, preparation method of negative electrode plate and lithium ion battery | |
| CN108232141B (en) | High-compaction lithium ion battery silicon-carbon composite negative electrode material and preparation method thereof | |
| CN111564612B (en) | High-thermal-conductivity and high-electrical-conductivity lithium battery positive electrode material and preparation method thereof | |
| CN110416522B (en) | Lithium-containing composite negative electrode material, preparation method thereof and application thereof in lithium secondary battery | |
| WO2022121281A1 (en) | Self-filling coated silicon-based composite material and preparation method therefor and application thereof | |
| CN112687853B (en) | Silica particle aggregate, preparation method thereof, negative electrode material and battery | |
| CN109473658A (en) | A kind of its lithium ion battery of the preparation method and application of lithium ion battery negative material | |
| CN113363473B (en) | Preparation method of high-first-efficiency SiO graphite composite negative electrode material | |
| CN112110448A (en) | Nitrogen-doped carbon and nano-silicon composite anode material and preparation method thereof | |
| US20240105941A1 (en) | Negative Electrode Material, Negative Electrode Plate, and Sodium Ion Battery | |
| CN113889594A (en) | Preparation method of boron-doped lithium lanthanum zirconate-coated graphite composite material | |
| CN111370656B (en) | Silicon-carbon composite material and preparation method and application thereof | |
| CN109686941B (en) | Method for preparing silicon-carbon negative electrode material for lithium ion power battery | |
| CN113422009B (en) | Lithium ion battery cathode material and preparation method and application thereof | |
| CN109638231B (en) | Silicon monoxide composite negative electrode material, preparation method thereof and lithium ion battery | |
| CN114105133B (en) | Graphite-silicon/silicon oxide-carbon composite material and preparation method and application thereof | |
| CN110600684A (en) | Silicon-carbon negative electrode material for lithium ion battery and preparation method thereof | |
| CN116799210A (en) | Composite lithium supplementing material and preparation method thereof, lithium supplementing coating and preparation method thereof, and lithium battery | |
| CN114843483A (en) | Hard carbon composite material and preparation method and application thereof | |
| CN115224241A (en) | Negative plate for lithium battery 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 |