CN110112364B - Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery - Google Patents

Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery Download PDF

Info

Publication number
CN110112364B
CN110112364B CN201910345513.9A CN201910345513A CN110112364B CN 110112364 B CN110112364 B CN 110112364B CN 201910345513 A CN201910345513 A CN 201910345513A CN 110112364 B CN110112364 B CN 110112364B
Authority
CN
China
Prior art keywords
silicon
carbon
precursor
multilayer composite
multilayer
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
Application number
CN201910345513.9A
Other languages
Chinese (zh)
Other versions
CN110112364A (en
Inventor
赖冠全
申红光
刘城
彭冲
李俊义
徐延铭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhuhai Cosmx Battery Co Ltd
Original Assignee
Zhuhai Cosmx Battery Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Zhuhai Cosmx Battery Co Ltd filed Critical Zhuhai Cosmx Battery Co Ltd
Priority to CN201910345513.9A priority Critical patent/CN110112364B/en
Publication of CN110112364A publication Critical patent/CN110112364A/en
Application granted granted Critical
Publication of CN110112364B publication Critical patent/CN110112364B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • 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
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M2004/026—Electrodes composed of, or comprising, active material characterised by the polarity
    • H01M2004/027—Negative electrodes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Composite Materials (AREA)
  • Inorganic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Battery Electrode And Active Subsutance (AREA)
  • Silicon Compounds (AREA)

Abstract

A multilayer composite negative electrode material and a preparation method thereof, a negative plate and a lithium battery are provided, wherein the preparation steps of the multilayer composite negative electrode material are as follows: preparing a multilayer precursor by taking silicon, silicon dioxide and carbon as raw materials, mixing a silicon material with a binder to obtain a first precursor layer mixture, mixing the silicon dioxide, a carbon material and the binder to obtain a second precursor layer mixture, and mixing the carbon material with the binder to obtain a third precursor layer mixture; carrying out compression molding on the mixture of the first, second and third precursor layers according to the sequence of the silicon layer, the silicon dioxide/carbon mixed layer and the carbon layer, and then carrying out sintering treatment to obtain a multilayer precursor; and reducing the silicon dioxide in the multilayer precursor into simple substance silicon to obtain the multilayer composite cathode material. The invention can generate a more compact solid electrolyte interface film in the first charge-discharge process, and simultaneously inhibit the volume expansion effect of the silicon material in the charge-discharge process, thereby improving the first efficiency, the specific capacity of the negative electrode and the cycle performance of the battery.

Description

Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery
Technical Field
The invention belongs to the technical field of power lithium ion batteries, and particularly relates to a composite negative electrode material of a power lithium ion battery.
Background
Along with the popularization of new energy electric vehicles, people have higher and higher requirements on the endurance capacity of power electric vehicles. The use of the positive and negative electrode materials with high specific capacity on the power battery plays an extremely important role in improving the endurance capacity of the battery. At present, the negative electrode material of the lithium ion power battery is mainly a graphite material, the theoretical specific capacity of graphite is 372mAh/g, the specific capacity of the graphite negative electrode material which is produced in mass at the present stage reaches more than 360mAh/g, the upper limit of the graphite material is basically reached, and the requirement of people on the high-energy density battery at the present stage is difficult to meet.
In recent years, various novel anode materials having high specific capacity have been developed. The silicon material has the advantages of high specific capacity, abundant resources, similar potential to the carbon material and the like, and thus, the silicon material becomes a research hotspot of a novel lithium ion battery cathode material. However, the silicon material has a serious volume effect (volume expansion is more than 400%) under high-degree lithium removal/insertion, which can cause silicon particles to break and pulverize, cause the structure of the negative electrode material to collapse and be separated from a conductive grid, and the internal resistance to be increased rapidly, finally cause the specific capacity of the negative electrode material to be attenuated rapidly, and the cycle performance of the battery to be poor.
In order to improve the volume expansion problem of the silicon material and improve the conductivity of the electrode material, the chinese patent application with publication number CN108110233A discloses a carbon-silicon composite material, which uses silicon dioxide and carbon as initial materials, mixes and sinters the two materials to obtain a precursor, and then reduces the silicon dioxide in the precursor to elemental silicon to obtain the carbon-silicon composite material. After the composite material compounds the elemental silicon and the carbon material together, the problem of volume expansion of the electrode material can be relieved, the first charge-discharge efficiency and the energy density of the battery are improved to a certain extent, the specific capacity of the battery is increased, and an improved space still exists.
Disclosure of Invention
The invention aims to provide a negative electrode material with a multilayer structure, high specific capacity, high first efficiency and long cycle life, which is composed of silicon, silicon dioxide and carbon, a preparation method thereof, and a negative plate and a lithium battery using the negative electrode material.
In order to achieve the purpose, the invention adopts the following technical solutions:
a preparation method of a multilayer composite anode material comprises the following steps:
preparing a multilayer precursor by taking a silicon material, silicon dioxide and a carbon material as raw materials, mixing the silicon material with a binder to obtain a first precursor layer mixture, mixing the silicon dioxide, the carbon material and the binder to obtain a second precursor layer mixture, and mixing the carbon material with the binder to obtain a third precursor layer mixture;
the first precursor layer mixture, the second precursor layer mixture and the third precursor layer mixture are subjected to compression molding according to the sequence of a silicon layer, a silicon dioxide/carbon mixed layer and a carbon layer;
sintering the mixture subjected to compression molding to obtain a multilayer precursor;
and reducing the silicon dioxide in the multilayer precursor into simple substance silicon to obtain the multilayer composite cathode material.
Further, the silicon material accounts for 2-35% by mass, the silicon dioxide material accounts for 3-75% by mass, and the carbon material accounts for 20-94% by mass.
Further, the silicon material is nanowire silicon, and/or the carbon material is one or a mixture of more of artificial graphite, natural graphite, hard carbon, soft carbon and mesocarbon microbeads.
Further, the first precursor layer mixture, the second precursor layer mixture and the third precursor layer mixture are respectively pressed into a sheet shape under the pressure of 5 MPa-36 MPa, and a multilayer mixture is pressed by stacking and pressing a silicon layer, a silicon dioxide/carbon mixed layer and a carbon layer in sequence.
Further, the sintering treatment comprises the following steps: and sintering the mixture for 1-36 hours at the temperature of 600-1400 ℃ in an inert atmosphere or under a vacuum condition.
Further, reducing the silicon dioxide in the multilayer precursor into simple substance silicon by adopting an electrochemical reduction method.
Further, the steps of reducing silicon by an electrochemical reduction method are as follows: and taking the multilayer precursor as a cathode, a graphite rod as an anode and molten salt as electrolyte, carrying out an electrolytic reaction under the protection of inert gas, and cleaning and drying a cathode electrolytic product after the electrolysis is finished to obtain the multilayer composite cathode material.
Further, during the electrolytic reaction, the electrolytic temperature is 500-1400 ℃, the electrolytic voltage is 1.2-3.2V, and the electrolytic time is 4-96 hours.
Further, after the electrolysis is finished, the cathode electrolysis product is sequentially subjected to deionized water washing, acid washing, deionized water washing and finally drying.
Furthermore, hydrochloric acid with the concentration of 5-40% is adopted during acid cleaning.
The invention also provides a multilayer composite anode material which is prepared by adopting the method.
The invention also provides the negative plate which comprises the signed multilayer composite negative material.
The invention also provides a lithium battery which comprises a positive plate and a negative plate, wherein the negative plate is a signed negative plate.
According to the technical scheme, the composition of the negative electrode material of the lithium ion power battery is optimized, different precursor layers are respectively formed by adopting silicon, silicon dioxide, carbon and carbon to form a multilayer composite structure, and after the silicon dioxide is reduced into simple substance silicon, the (nano wire) silicon is compounded with the silicon dioxide and the carbon, the (nano wire) silicon grows on the silicon dioxide and the (nano) carbon, so that a more compact solid electrolyte interface film (SEI film) can be generated in the first charge-discharge process, the first efficiency and the negative electrode specific capacity of the battery are improved, the compounding of the silicon and the carbon can also play a role in inhibiting the volume expansion effect of the silicon material in the charge-discharge process, and the cycle performance of the battery is improved. The invention can also reduce the preparation cost of the silicon-carbon cathode material and improve the problem of environmental pollution in the production process of the traditional silicon-based cathode material.
Drawings
FIG. 1 is a flow chart of an embodiment of the present invention;
fig. 2 is a schematic diagram of silicon reduction by an electrochemical reduction method according to an embodiment of the present invention.
The following detailed description of the present invention will be made with reference to the accompanying drawings
Detailed Description
In order to make the aforementioned and other objects, features and advantages of the invention more apparent, embodiments of the invention are described in detail below.
The silicon/silicon dioxide/carbon multilayer composite cathode material is a multilayer composite material prepared by compounding three materials of silicon, silicon dioxide and carbon, and the multilayer structure comprises a silicon layer, a silicon dioxide/carbon mixed layer and a carbon layer, wherein the mass percent of the silicon material is 2-35%, the mass percent of the silicon dioxide material is 3-75%, and the mass percent of the carbon material is 20-94%.
As shown in fig. 1, the preparation method of the silicon/silica/carbon multilayer composite material of the present invention comprises the following steps:
preparing a multilayer precursor; respectively taking silicon, silicon dioxide, carbon and carbon as initial raw materials to prepare a first precursor layer, a second precursor layer and a third precursor layer, wherein the first precursor layer is a silicon layer formed by pressing pure silicon, preferably nanowire silicon, the second precursor layer is a carbon layer formed by pressing a carbon material, preferably a nanocarbon material, the third precursor layer is a silicon dioxide/carbon mixed layer formed by mixing and pressing silicon dioxide and the carbon material serving as the initial raw materials, preferably nano polycrystalline silicon dioxide and the nanocarbon material; proportioning the use amount of each layer of material according to a target product, respectively adding a proper amount of binder to perform ball milling (ball milling for 2-36 hours) to obtain initial powder of each layer of precursor, then respectively pressing into sheet-shaped objects under the condition of 5-36 MPa, sequentially laminating silicon layers, silicon dioxide/carbon layers and carbon layers, pressing into mixed sheet-shaped objects with a sandwich structure, and sintering the mixed sheet-shaped objects obtained by pressing at 600-1400 ℃ for 1-36 hours under an inert atmosphere or a vacuum condition to obtain a multi-layer precursor with certain strength; the addition amount of the binder is determined according to the mass of the powder raw materials of each layer and the compactness of the precursor, and is an empirical value, generally 2-50% of the mass of the powder raw materials of each layer; the silicon dioxide and the carbon material in the silicon dioxide/carbon mixed layer do not need to be matched according to a specific proportion, the silicon dioxide and the carbon material can be mixed according to any proportion to prepare the silicon dioxide/carbon mixed layer, and then the dosage of the other two layers of materials is matched according to the dosage of the silicon dioxide/carbon mixed layer;
a silicon reduction step; silicon dioxide in the precursor can be reduced into silicon by adopting an electrochemical reduction method, namely, the multilayer precursor is used as a cathode, a graphite rod is used as an anode, molten salt is used as an electrolyte, and electrolytic reaction is carried out under the protection of inert gas, and the method comprises the following specific steps: as shown in fig. 2, a multilayer precursor is used as a cathode, for example, the multilayer precursor is wrapped by nickel foam in a sandwich manner and then connected with an iron-chromium-aluminum wire to prepare a cathode system, a high-purity graphite rod is used as an anode, the cathode and the anode are placed in a crucible, the crucible is used as an electrolytic cell, heating equipment is a crucible resistance furnace, a power supply is a direct-current stabilized voltage power supply, an electrolytic reaction is carried out in an electrolytic furnace under the protection of inert gas at the electrolytic temperature of 500-1400 ℃ and the electrolytic voltage of 1.2-3.2V, and the electrolytic time is 4-96 hours;
cleaning and drying; and after the electrolysis is finished, cooling the cathode electrolysis product to room temperature (the whole process of electrolysis and cooling is protected by inert gas), taking out the cathode electrolysis product, sequentially washing with deionized water, pickling and washing with deionized water, and drying at 80-200 ℃ in the air to obtain the silicon/silicon dioxide/carbon multilayer composite material.
The silicon dioxide used in the invention can be an analytical pure material, and the carbon material can be one or a mixture of more of materials such as artificial graphite, natural graphite, hard carbon, soft carbon, mesocarbon microbeads and the like. The inert gas used may be argon. The crucible used in the electrolysis reaction can be a corundum crucible or a stainless steel crucible, and the molten salt used in the electrolysis reaction can be one or a mixture of more of calcium chloride, magnesium chloride, potassium chloride and sodium chloride. Hydrochloric acid with the concentration of 5-40% can be adopted during acid cleaning.
The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The present invention will be further illustrated by the following specific examples and comparative examples. The reagents, materials and instruments used in the following description are all conventional reagents, conventional materials and conventional instruments, which are commercially available, and the reagents may be synthesized by a conventional synthesis method, if not specifically described.
Example 1
Mixing 0.209g of silicon dioxide and 1.800g of artificial graphite, adding 0.05g of polyvinyl butyral (binder), then carrying out ball milling uniformly to obtain uniform powder serving as silicon/silicon dioxide layer precursor powder, and mixing SiO2Pressing the/C mixed powder into a sheet, respectively pressing 0.200g of pure silicon and 0.900g of pure carbon powder into a sheet, and then pressing according to Si | SiO2the/C | C is sequentially molded into a sheet-shaped object with a multilayer structure, then the mixed sheet-shaped object is placed into a sintering furnace, argon is filled, the temperature is raised to 680 ℃, and sintering is carried out for 13 hours to prepare a multilayer precursor;
connecting and leading out a multilayer precursor as a cathode by using an electronic conducting material, taking a high-purity graphite rod as an anode, weighing 380 g of calcium chloride (fused salt) in an electrolytic furnace by taking a corundum crucible as an electrolytic tank, putting the fused salt into a ceramic crucible, introducing argon into a crucible resistance furnace, heating to 1000 ℃ to melt the fused salt, putting the cathode and the anode into the ceramic crucible, connecting a direct-current stabilized power supply with the anode and the cathode, electrifying for 2.8V, and carrying out an electrolytic reaction for 46 hours;
and after the electrolysis is finished, washing the cathode electrolysis product with deionized water, ultrasonically assisting 36% (mass fraction) hydrochloric acid, washing with deionized water in sequence, and drying at 120 ℃ in air to obtain the silicon/silicon dioxide/carbon multilayer composite cathode material.
Example 2
Mixing 0.618g of silicon dioxide and 2.600g of artificial graphite, adding 0.18g of polyvinyl butyral, and then carrying out ball milling uniformly to obtain uniform powderFor the silicon/silicon dioxide layer precursor powder, SiO2Pressing the/C mixed powder into a sheet, respectively pressing 0.800g of pure silicon and 0.200g of pure carbon powder into a sheet, and then pressing according to SiO2|SiO2the/C | C is sequentially molded into a sheet-shaped object with a three-layer structure, then the mixed sheet-shaped object is placed into a sintering furnace, argon is filled, the temperature is raised to 850 ℃ and sintering is carried out for 8 hours to prepare a multilayer precursor;
connecting and leading out a multilayer precursor by using an electronic conductive material to be used as a cathode, using a high-purity graphite rod as an anode, weighing 400g of calcium chloride in an electrolytic cell by using a stainless steel crucible as an electrolytic tank, putting the calcium chloride into the stainless steel crucible, introducing argon into a crucible resistance furnace, heating to 1000 ℃ to melt the calcium chloride, putting the cathode and the anode into the stainless steel crucible, connecting a direct-current stabilized power supply with the anode and the cathode, electrifying for 3.0V, and carrying out an electrolytic reaction for 32 hours;
and after the electrolysis is finished, washing the cathode electrolysis product with deionized water, ultrasonically assisting 36% hydrochloric acid pickling and deionized water washing in sequence, and drying in air at 120 ℃ to obtain the silicon/silicon dioxide/carbon multilayer composite cathode material.
Example 3
Mixing 0.991g of silicon dioxide and 2.800g of artificial graphite, adding 0.22g of polyvinyl butyral, then carrying out ball milling uniformly to obtain uniform powder serving as silicon/silicon dioxide layer precursor powder, pressing SiO2/C mixed powder into sheets, respectively pressing 0.100g of pure silicon and 0.400g of pure carbon powder into sheets, and then pressing according to SiO2|SiO2the/C | C is sequentially molded into a sheet-shaped object with a three-layer structure, then the sheet-shaped object is placed into a sintering furnace, argon is filled, the temperature is increased to 920 ℃, and sintering is carried out for 7 hours to prepare a multilayer precursor;
connecting and leading out a multilayer precursor by using an electronic conductive material as a cathode, using a high-purity graphite rod as an anode, weighing 400g of sodium chloride in an electrolytic cell by using a corundum crucible as an electrolytic tank, putting the sodium chloride into a ceramic crucible, introducing argon into a crucible resistance furnace, heating to 1300 ℃ to melt the sodium chloride, putting the cathode and the anode into the ceramic crucible, connecting a direct-current stabilized power supply with a positive electrode and a negative electrode, electrifying for 3.1V, and carrying out an electrolytic reaction for 40 hours;
and after the electrolysis is finished, washing the cathode electrolysis product with deionized water, ultrasonically assisting 32% hydrochloric acid pickling and deionized water washing in sequence, and drying in the air at 150 ℃ to obtain the silicon/silicon dioxide/carbon multilayer composite cathode material.
Comparative example
The comparative example adopts the method provided by the patent application of CN108110233A Chinese invention to prepare the carbon-silicon composite anode material, and the specific preparation scheme is as follows:
weighing 0.6 g of silicon dioxide, 2.52 g of soft carbon powder and 0.08 g of polyvinyl butyral, uniformly mixing to form a mixture (in the mixture, the mass fraction of the silicon dioxide is 18.75%, the mass fraction of the soft carbon powder is 78.75% and the mass fraction of the polyvinyl butyral is 2.5%), pressing and molding the mixture under the pressure of 10MPa to form a sheet-shaped object, putting the sheet-shaped object into a sintering furnace, filling argon, heating to 600 ℃, and sintering for 12 hours to obtain a precursor;
connecting and leading out a precursor as a cathode by using an electronic conducting material, using a high-purity graphite rod as an anode, taking a ceramic crucible as an electrolytic tank in an electrolytic furnace, weighing 60 g of potassium chloride, 150 g of magnesium chloride and 90 g of sodium chloride (potassium chloride: magnesium chloride: sodium chloride: 0.2: 0.5: 0.3), putting the potassium chloride, the magnesium chloride and the sodium chloride into the ceramic crucible, introducing argon into a crucible resistance furnace, heating to 700 ℃ to melt molten salt, putting a cathode and an anode into the ceramic crucible, connecting a direct-current stabilized power supply with a positive electrode and a negative electrode, electrifying for 2.8V, and carrying out an electrolytic reaction for 60 hours;
and after the electrolytic reaction is finished, washing the cathode electrolytic product with deionized water, ultrasonically assisting 36% hydrochloric acid pickling and deionized water washing in sequence, and finally drying in the air at 150 ℃ to obtain the silicon-carbon composite material.
The composite materials prepared in the examples 1-3 and the comparative example are used as negative electrode materials, and the negative electrode sheet is prepared by adopting a conventional negative electrode sheet preparation process, namely the composite materials, the conductive agent and the binder are uniformly mixed and then coated on copper foil to obtain a negative electrode sheet, and the negative electrode sheet is matched with a conventional ternary material positive electrode sheet to assemble a full cell with the model number of 2025.
Batteries fabricated using the negative electrode materials of examples 1-3 and comparative example were subjected to specific capacity and cycle performance tests, the results of which are shown in the following table:
Figure BDA0002042153570000071
as can be seen from Table 1, the silicon/silicon dioxide/carbon multi-layer multi-component composite material prepared by the method of the invention has higher specific capacity and first charge-discharge efficiency and longer cycle life compared with the single-layer silicon/carbon composite material. The invention adopts different materials to prepare the cathode material with a multilayer structure, the material layers with different components have different expansion degrees in the circulation process, each layer of material not only can inhibit the volume expansion of the cathode in the circulation process and improve the circulation performance of the battery, but also can obtain the cathode material with high capacity by respectively preparing the silicon layer and the carbon layer on the two sides of the silicon/carbon layer, thereby improving the energy density of the battery. The composite cathode material can accurately obtain the required cathode materials with different proportions of components by pressing for multiple times and controlling the conditions such as reaction time, reaction temperature, voltage and the like, thereby improving the first efficiency and the electrical property of the cathode material.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (13)

1. The preparation method of the multilayer composite anode material is characterized by comprising the following steps of:
preparing a multilayer precursor by taking a silicon material, silicon dioxide and a carbon material as raw materials, mixing the silicon material with a binder to obtain a first precursor layer mixture, mixing the silicon dioxide, the carbon material and the binder to obtain a second precursor layer mixture, and mixing the carbon material with the binder to obtain a third precursor layer mixture;
pressing the first precursor layer mixture into a silicon layer sheet, pressing the second precursor layer mixture into a silicon dioxide/carbon layer sheet, pressing the third precursor layer mixture into a carbon layer sheet, and carrying out compression molding according to the sequence of the silicon layer sheet, the silicon dioxide/carbon mixed layer sheet and the carbon layer sheet to obtain a sheet with a multilayer structure;
sintering the multi-layer structure sheet-shaped object subjected to compression molding to obtain a multi-layer precursor;
and reducing the silicon dioxide in the multilayer precursor into simple substance silicon to obtain the multilayer composite cathode material.
2. The method of preparing a multilayer composite anode material according to claim 1, wherein: the silicon material accounts for 2-35% by mass, the silicon dioxide material accounts for 3-75% by mass, and the carbon material accounts for 20-94% by mass.
3. The method for producing a multilayer composite anode material according to claim 1 or 2, characterized in that: the silicon material is nano-wire silicon, and/or the carbon material is one or a mixture of more of artificial graphite, natural graphite, hard carbon, soft carbon and mesocarbon microbeads.
4. The method for producing a multilayer composite anode material according to claim 1 or 2, characterized in that: and respectively pressing the first precursor layer mixture, the second precursor layer mixture and the third precursor layer mixture into sheets under the pressure of 5-36 MPa, and stacking and pressing a silicon layer, a silicon dioxide/carbon mixed layer and a carbon layer in sequence to form a multilayer mixture.
5. The method for producing a multilayer composite anode material according to claim 1 or 2, characterized in that: the sintering treatment comprises the following steps: and sintering the mixture for 1-36 hours at the temperature of 600-1400 ℃ in an inert atmosphere or under a vacuum condition.
6. The method for producing a multilayer composite anode material according to claim 1 or 2, characterized in that: and reducing the silicon dioxide in the multilayer precursor into simple substance silicon by adopting an electrochemical reduction method.
7. The method of preparing a multilayer composite anode material according to claim 6, wherein: the steps of reducing silicon by an electrochemical reduction method are as follows:
and taking the multilayer precursor as a cathode, a graphite rod as an anode and molten salt as electrolyte, carrying out an electrolytic reaction under the protection of inert gas, and cleaning and drying a cathode electrolytic product after the electrolysis is finished to obtain the multilayer composite cathode material.
8. The method of preparing a multilayer composite anode material according to claim 7, wherein: during the electrolytic reaction, the electrolytic temperature is 500-1400 ℃, the electrolytic voltage is 1.2-3.2V, and the electrolytic time is 4-96 hours.
9. The method for preparing a multilayer composite anode material according to claim 7 or 8, wherein: and after the electrolysis is finished, sequentially washing the cathode electrolysis product with deionized water, pickling, washing with deionized water, and finally drying.
10. The method of preparing a multilayer composite anode material according to claim 9, wherein: hydrochloric acid with the concentration of 5-40% is adopted during acid cleaning.
11. A multilayer composite anode material, characterized in that: the multilayer composite anode material is prepared by the preparation method of the multilayer composite anode material as claimed in any one of claims 1 to 10.
12. A negative plate is characterized in that: the negative electrode sheet comprises the multilayer composite negative electrode material according to claim 11.
13. A lithium battery comprises a positive plate and a negative plate, and is characterized in that: the negative electrode sheet according to claim 12.
CN201910345513.9A 2019-04-26 2019-04-26 Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery Active CN110112364B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910345513.9A CN110112364B (en) 2019-04-26 2019-04-26 Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910345513.9A CN110112364B (en) 2019-04-26 2019-04-26 Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery

Publications (2)

Publication Number Publication Date
CN110112364A CN110112364A (en) 2019-08-09
CN110112364B true CN110112364B (en) 2021-02-19

Family

ID=67486984

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910345513.9A Active CN110112364B (en) 2019-04-26 2019-04-26 Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery

Country Status (1)

Country Link
CN (1) CN110112364B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112542572A (en) * 2019-09-23 2021-03-23 珠海冠宇电池股份有限公司 Novel lithium ion battery positive pole piece and preparation method and application thereof
CN114195152B (en) * 2020-09-02 2023-06-16 北京清创硅谷科技有限公司 Carbon-silicon composite material for lithium ion battery cathode material and preparation method thereof

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104319402A (en) * 2014-10-28 2015-01-28 上海交通大学 Preparation method for multi-layer carbon hollow sphere anode material
CN107293700A (en) * 2016-03-31 2017-10-24 比亚迪股份有限公司 A kind of lithium ion battery anode active material and preparation method thereof, negative pole and battery

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20170040598A1 (en) * 2015-08-07 2017-02-09 Enevate Corporation Surface modification of silicon particles for electrochemical storage
CN103794769B (en) * 2014-02-18 2016-05-04 江苏华东锂电技术研究院有限公司 The preparation method of lithium ion battery negative material
CN104218213B (en) * 2014-08-15 2017-02-22 中山大学 Multilayer membrane electrode and preparation method and application thereof
CN106654185B (en) * 2015-11-03 2020-05-22 宝山钢铁股份有限公司 Silicon-based negative electrode active material for lithium ion battery and preparation method thereof
CN106571451A (en) * 2016-10-26 2017-04-19 浙江天能能源科技股份有限公司 Lithium ion battery anode material, and preparation method thereof
CN106784700B (en) * 2016-12-27 2020-02-18 电子科技大学 Multilayer silicon/graphene composite lithium battery cathode material and preparation method thereof
CN108110233A (en) * 2017-12-07 2018-06-01 银隆新能源股份有限公司 A kind of Si-C composite material and preparation method thereof, negative plate, lithium battery
CN108717975A (en) * 2018-08-14 2018-10-30 银隆新能源股份有限公司 A kind of preparation method of negative material, battery and its negative material
CN109585785A (en) * 2018-11-22 2019-04-05 江苏科技大学 A method of Si/CNF/C composite material and lithium ion battery negative electrode material are prepared based on waste plastics

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104319402A (en) * 2014-10-28 2015-01-28 上海交通大学 Preparation method for multi-layer carbon hollow sphere anode material
CN107293700A (en) * 2016-03-31 2017-10-24 比亚迪股份有限公司 A kind of lithium ion battery anode active material and preparation method thereof, negative pole and battery

Also Published As

Publication number Publication date
CN110112364A (en) 2019-08-09

Similar Documents

Publication Publication Date Title
EP2778130B1 (en) Nano-silicon/carbon composite material and preparation method therefor
CN103515657B (en) Battery
CN105098138B (en) Negative electrode for lithium ion battery piece and preparation method thereof
CN110518254B (en) Negative current collector for lithium metal battery and preparation method and application thereof
CN102496704B (en) Lithium titanate/titanium black anode material and preparation method thereof
CN102569757B (en) Process for preparing materials of negative electrodes of copper-silicon-aluminum nano-porous lithium-ion batteries
KR101762275B1 (en) Method for preparing solid elecrolyte by low temperature sintering process and method for manufacturing all-solid-state lithium secondary battery comprising the same
CN103560233A (en) Carbon coated silicon graphite cathode material of lithium ion battery and preparation method thereof
CN104852028A (en) Lithium titanate/graphene composite cathode material for lithium ion battery
CN107732170A (en) A kind of efficiently lithium metal composite and preparation method thereof and the application as negative pole
CN110767891B (en) Preparation method of porous spherical silicon-based composite anode material
CN110112364B (en) Multilayer composite negative electrode material, preparation method thereof, negative plate and lithium battery
CN106099095A (en) The preparation method of fluorine nitrogen co-doped carbon cladding lithium titanate nanometer sheet
CN103236528A (en) Germanium-carbon-graphene composite material, and preparation method and application thereof
CN103579627A (en) Graphene-tin composite material, preparation method of graphene-tin composite material, lithium ion battery and preparation method of lithium ion battery
CN108110233A (en) A kind of Si-C composite material and preparation method thereof, negative plate, lithium battery
CN103531776B (en) The lithium ion battery and its positive electrode and chemical synthesizing method of high security extra long life
CN207719320U (en) A kind of modified lithium battery electrode structure, lithium battery structure
CN108963237B (en) Preparation method of sodium ion battery negative electrode material
CN104638248A (en) Method for preparing graphene/lead compound composite material
CN104157877A (en) Lithium ion battery electrical core and preparation method thereof
CN111705315B (en) Preparation method of modified copper three-dimensional framework and application of modified copper three-dimensional framework in lithium battery
CN109546081A (en) A kind of blended anode pole piece and preparation method thereof, lithium ion battery
CN107611461A (en) A kind of preparation method of SOFC
CN114188521B (en) Light coating layer on surface of graphite anode material of double-ion battery and preparation method

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
CB02 Change of applicant information
CB02 Change of applicant information

Address after: 519180 No. 209, Pearl Peak Avenue, Jingan Town, Doumen District, Zhuhai City, Guangdong Province (South First Floor of A Factory Building)

Applicant after: Zhuhai CosMX Battery Co.,Ltd.

Address before: 519180 No. 209, Pearl Peak Avenue, Jingan Town, Doumen District, Zhuhai City, Guangdong Province (South First Floor of A Factory Building)

Applicant before: ZHUHAI COSLIGHT BATTERY Co.,Ltd.

GR01 Patent grant
GR01 Patent grant