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
  • H01M4/38—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
  • 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
  • H01M4/362—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
  • H01M4/58—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
  • H01M4/587—Carbonaceous material, e.g. graphite-intercalation compounds or CFx for inserting or intercalating light metals
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
  • H01M4/00—Electrodes
  • H01M4/02—Electrodes composed of, or comprising, active material
  • H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
  • H01M4/628—Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• • 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
  • H01M2004/021—Physical characteristics, e.g. porosity, surface area
• • 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

Definitions

• the present invention relates to the field of lithium ion battery technology, in particular to a silicon carbon negative electrode material for lithium ion batteries and a preparation method thereof.
• Lithium-ion secondary batteries have excellent comprehensive performance such as high power characteristics. In the past ten years, it has been successfully and widely used in the field of mobile electronic terminal equipment.
• lithium-ion battery performance mainly depends on the performance of lithium intercalation and deintercalation electrode materials.
• commercial lithium-ion batteries widely use mesophase carbon microspheres and modified graphite as negative electrode materials, but there are disadvantages such as low theoretical lithium storage capacity (graphite is 372mAh/g) and organic solvent co-intercalation. Therefore, high-capacity lithium
• graphite is 372mAh/g
• organic solvent co-intercalation Therefore, high-capacity lithium
• the research and application of anode materials for ion batteries has become the key to improving battery performance.
• silicon has the highest theoretical capacity (when the mass of intercalated lithium is not included, it is approximately 4200mAh/g) and a relatively moderate lithium insertion/desorption potential (about 0.1-0.5V v s.Li/Li+), which is very suitable as a negative electrode material for lithium-ion batteries.
• silicon-based materials have serious volume effects under high-level lithium insertion and release conditions, which can easily lead to structural collapse of the material and peeling of the electrode material, causing the electrode material to lose electrical contact, resulting in a sharp decline in the cycle performance of the electrode.
• the main purpose of the present invention is to provide a silicon-carbon negative electrode material for lithium ion batteries and a preparation method thereof in view of the deficiencies in the prior art.
• the prepared silicon-carbon negative electrode material has a large first-time reversible capacity and excellent cycle performance.
• the preparation method is simple and is conducive to industrialization.
• a preparation method of silicon carbon negative electrode material for lithium ion battery includes the following steps:
• Block making Put the silicon-carbon negative electrode material precursor prepared in step (1) into a rubber mold, and place it in an isostatic press molding machine for molding at a pressure of 100-300 MPa to obtain an isostatically pressed block;
• step (3) Carbonization: Place the block obtained in step (2) in a nitrogen atmosphere protection furnace for sintering, raise it to 400-1000°C at a heating rate of 2-25°C/min and keep it for 4-18 hours, crush and screen Then the silicon carbon anode material is obtained.
• the graphite precursor is one or a mixture of artificial graphite or natural graphite, and the average particle size D50 is 5-10 ⁇ m.
• the binder in the step (1) is a mixture of one or more of coal-based or oil-based asphalt, with a softening point of 200-300 °C.
• the average particle size D50 of the nano-silicon in the step (1) is 10-100 nm.
• the mechanical fusion treatment in the step (1) is: the rotation speed is 600-1000 rpm.
• the mass ratio of the graphite precursor, the binder, and the nano silicon in the step (1) is 1:0.01-0.1:0.01-0.1.
• a silicon carbon negative electrode material for lithium ion batteries is prepared by using the aforementioned preparation method of a silicon carbon negative electrode material for lithium ion batteries.
• the present invention adopts simple block asphalt pore-making technology and uses less than 10% of the asphalt dosage to realize the integrated preparation of coating and pore-making.
• the asphalt not only coats the surface of graphite and nano silicon with a layer Uniform amorphous carbon.
• the volatilization of the pitch will cause a certain inhibition.
• the carbide produced during the carbonization of the pitch will become a pore former.
• Inside the block is the surface of nano silicon and graphite. A variety of uniform network-like pores are formed, so that the nano-silicon is under a coating layer with many pores. These pores can better alleviate the volume expansion effect of nano-silicon in the prior art, thereby first charging and discharging efficiency and cycle stability.
• the preparation method of the invention has simple process, convenient operation and few production equipment, thereby further reducing the cost, facilitating popularization and application, and being suitable for large-scale production.
• Figure 1 is an SEM image of the present invention.
• the invention discloses a preparation method of a silicon carbon negative electrode material for lithium ion batteries, which includes the following steps:
• the graphite precursor is one or a mixture of artificial graphite or natural graphite
• the average particle size D50 is 5-10 ⁇ m
• the binder is one or a mixture of coal-based or oil-based pitch
• the softening point is 200-300 °C
• the average particle size D50 of nano-silicon is 10-100nm
• the mechanical fusion treatment is: the rotation speed is 600-1000rpm.
• the mass ratio of graphite precursor, binder, and nano-silicon is 1:0.01-0.1:0.01-0.1.
• Block making Put the silicon-carbon negative electrode material precursor prepared in step (1) into a rubber mold, and place it in an isostatic pressing molding machine for molding at a pressure of 100-300 MPa to obtain an isostatic pressed block.
• step (3) Carbonization: Place the block obtained in step (2) in a nitrogen atmosphere protection furnace for sintering, raise it to 400-1000°C at a heating rate of 2-25°C/min and keep it for 4-18 hours, crush and screen Then the silicon carbon anode material is obtained.
• the invention also discloses a silicon carbon negative electrode material for lithium ion batteries, which is prepared by adopting the aforementioned preparation method of a silicon carbon negative electrode material for lithium ion batteries.
• a preparation method of silicon carbon negative electrode material for lithium ion battery includes the following steps:
• the graphite precursor is artificial graphite
• the average particle size D50 is 8 ⁇ m
• the binder is coal-based pitch
• the softening point is 250°C
• the average particle size D50 of nano-silicon is 60nm
• the mechanical fusion treatment is: the rotation speed is 900rpm.
• the mass ratio of graphite precursor, binder, and nano-silicon is 1: 0.1:0.05.
• Block making Put the silicon-carbon negative electrode material precursor prepared in step (1) into a rubber mold, and place it in an isostatic pressing machine for molding at a pressure of 250 MPa to obtain an isostatic pressed block.
• step (3) Carbonization: Place the block obtained in step (2) in a nitrogen atmosphere protection furnace for sintering, raise it to 800°C at a heating rate of 15°C/min and keep it for 10 hours. After crushing and sieving, the silicon carbon anode material is obtained .
• the invention also discloses a silicon carbon negative electrode material for lithium ion batteries, which is prepared by adopting the aforementioned preparation method of a silicon carbon negative electrode material for lithium ion batteries.
• a preparation method of silicon carbon negative electrode material for lithium ion battery includes the following steps:
• the graphite precursor is natural graphite
• the average particle size D50 is 10 ⁇ m
• the binder is oil-based pitch
• the softening point is 300°C
• the average particle size D50 of nano-silicon is 100 nm
• the mechanical fusion treatment is: the rotation speed is 1000 rpm.
• the mass ratio of graphite precursor, binder, and nano-silicon is 1:0.05: 0.1.
• Block making Put the silicon-carbon negative electrode material precursor prepared in step (1) into a rubber mold, and place it in an isostatic pressing molding machine for molding at a pressure of 300 MPa to obtain an isostatic pressed block.
• step (3) Carbonization: Place the block obtained in step (2) in a nitrogen atmosphere protection furnace for sintering, raise it to 1000°C at a heating rate of 25°C/min and keep it for 18 hours, crush and screen to obtain silicon carbon anode material .
• the invention also discloses a silicon carbon negative electrode material for lithium ion batteries, which is prepared by adopting the aforementioned preparation method of a silicon carbon negative electrode material for lithium ion batteries.
• a preparation method of silicon carbon negative electrode material for lithium ion battery includes the following steps:
• the graphite precursor is a mixture of artificial graphite and natural graphite.
• the average particle size D50 is 5 ⁇ m.
• the binder is a mixture of coal-based pitch and oil-based pitch.
• the softening point is 200°C.
• the average particle size D50 of nano-silicon is 10nm.
• the fusion treatment is: the rotation speed is 600 rpm.
• the mass ratio of graphite precursor, binder, and nano-silicon is 1:0.02:0.08.
• Block making Put the silicon-carbon negative electrode material precursor prepared in step (1) into a rubber mold, and place it in an isostatic press molding machine for molding at a pressure of 100 MPa to obtain an isostatically pressed block.
• step (3) Carbonization: Place the block obtained in step (2) in a nitrogen atmosphere protection furnace for sintering, raise it to 400°C at a heating rate of 2°C/min and keep it for 4 hours. After crushing and sieving, the silicon carbon anode material is obtained .
• the invention also discloses a silicon carbon negative electrode material for lithium ion batteries, which is prepared by adopting the aforementioned preparation method of a silicon carbon negative electrode material for lithium ion batteries.
• Comparative Example 1 The nano-silicon material directly coated with carbon on the silicon surface has only steps (1) and (3) and no step (2).
• a computer-controlled charge and discharge cabinet is used for data collection and control.
• the prepared silicon carbon anode material has excellent capacity performance, cycle performance, and first charge and discharge efficiency.
• the porous carbon layer structure formed by the volatilization of pitch plays a very important role: the uniform pore structure can effectively alleviate the volume expansion effect of silicon during the deintercalation of lithium, and inhibit the powdering of active materials.
• the design focus of the present invention is: the present invention adopts simple block asphalt pore-making technology, uses less than 10% of the asphalt dosage, and realizes the integrated preparation of coating and pore-making.
• the asphalt is not only in graphite and nanometer
• the surface of the silicon is coated with a uniform layer of amorphous carbon.
• the carbide produced during the carbonization of the pitch will become a pore former, which is also in the interior of the block. It is the surface of nano-silicon and graphite that form various uniform network-like pores, so that the nano-silicon is under a coating layer with many pores.
• the charging and discharging efficiency and cycle stability can be greatly improved.
• the preparation method of the invention has simple process, convenient operation and few production equipment, thereby further reducing the cost, facilitating popularization and application, and being suitable for large-scale production.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=72565175

Family Applications (1)

Country Status (3)

Cited By (2)

Families Citing this family (4)

Citations (6)

Family Cites Families (3)

• 2020
  • 2020-05-26 CN CN202010456796.7A patent/CN111725504B/zh active Active
• 2021
  • 2021-05-07 WO PCT/CN2021/091977 patent/WO2021238600A1/zh active Application Filing
  • 2021-05-07 KR KR1020227013148A patent/KR20220104684A/ko unknown

Patent Citations (6)

Also Published As

Similar Documents

Legal Events