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CN-122000326-A - Preparation method of silicon-based anode material coated by mixed biomass carbon

CN122000326ACN 122000326 ACN122000326 ACN 122000326ACN-122000326-A

Abstract

The invention provides a preparation method of a silicon-based anode material coated by mixed biomass carbon, wherein the biomass carbon is mainly derived from prolamin, glutenin and high-activity yeast. The prolamine and the glutenin form a reticular structure when meeting water under the catalysis of high-activity yeast, and the flexibility of the carbonized porous anode material can be adjusted by adding different proportions, so that the flexible porous nitrogen-doped carbon-coated silicon-based anode material can be obtained, the problem of volume expansion in the electrochemical process of the silicon anode is relieved, the conductivity is improved, and excellent electrochemical performance is shown. The porous silicon-based negative electrode material with controllable flexibility is obtained through drying and high-temperature annealing, the method is simple and effective, the cost is low, and the prepared composite silicon-based negative electrode material has excellent performance and is suitable for mass production.

Inventors

  • HOU LIJUAN
  • LIU QI
  • CHEN XINYUAN
  • CHEN RENJIE
  • LI LI

Assignees

  • 北京理工大学

Dates

Publication Date
20260508
Application Date
20260205

Claims (7)

  1. 1. The silicon-based anode material coated by the mixed biomass carbon is characterized by being prepared by the following steps: (1) Mixing and grinding prolamin, glutenin and high-activity yeast according to the mass ratio of 1:x (1+x)/2 to obtain mixed powder I; (2) Adding silicon negative electrode powder into the mixed powder I, further grinding, adding a proper amount of deionized water, and performing ultrasonic dispersion to obtain a uniform mixed solution; (3) Drying the obtained uniform mixed solution to obtain a precursor material; (4) And carrying out high-temperature annealing treatment on the obtained precursor material to obtain the silicon-based anode material coated with the mixed biomass carbon.
  2. 2. The hybrid biomass carbon coated silicon-based anode material of claim 1, wherein in step (1), x in 1:x (1+x)/2 is 0.5-2.
  3. 3. The mixed biomass carbon coated silicon-based anode material of claim 1, wherein in the step (2), the addition amount of the silicon anode is determined by a silicon-carbon mass ratio, and the silicon-carbon mass ratio is 0.2-10.
  4. 4. A mixed biomass carbon coated silicon-based anode material as claimed in claim 1 wherein in step (3), the drying method is freeze drying or spray drying until the material is in powder form.
  5. 5. The silicon-based anode material coated with mixed biomass carbon as claimed in claim 1, wherein in the step (4), the high-temperature annealing device is a tube furnace, argon is introduced in the annealing process, and the air flow is 50-300 cfm.
  6. 6. The mixed biomass carbon coated silicon-based anode material according to claim 1, wherein in the step (4), the high-temperature annealing temperature is 600-800 ℃, and the annealing time is 0.5-5 h.
  7. 7. A lithium ion battery is characterized in that a silicon-based anode material coated by mixed biomass carbon according to any one of claims 1-6 is adopted as an anode material of the battery.

Description

Preparation method of silicon-based anode material coated by mixed biomass carbon Technical Field The invention relates to a preparation method of a silicon-based anode material coated by mixed biomass carbon, and belongs to the technical field of lithium ion batteries. Background In recent years, with the rapid development of electric vehicles and 3C electronic products, the demand for high-energy density and high-rate batteries is rising year by year. How to improve the energy density, the multiplying power performance and the safety of battery materials has become a problem to be solved. The theoretical capacity of the graphite material adopted by the commercial negative electrode is 372 mAh/g, and the requirement of a lithium ion battery with high energy density is difficult to meet. Silicon anodes have been attractive because of their excellent theoretical capacity (4200 mAh/g) and low cost. When silicon is used as a negative electrode of a lithium ion battery to participate in the reaction, an energy storage mechanism is alloying reaction, the volume expansion rate reaches approximately 300% in the circulation process, the generated internal stress can cause collapse and crushing of a material structure, the generation of a solid electrolyte interface film (SEI) is accelerated, and finally, the battery capacity is reduced, the circulation performance is deteriorated and the initial efficiency is low. The problem of volume expansion of silicon anodes has become a great obstacle to their commercial application in the field of lithium ion batteries. By compounding silicon with a carbon material having excellent structural stability and ductility, the volume expansion phenomenon of silicon in the charge-discharge process can be controlled and reduced, and the high conductivity of the carbon material can further improve the electrochemical performance of the composite material. Common carbon materials can be divided into two types, one is conductive materials such as carbon nanotubes and reduced graphene oxide, and the other is organic carbon materials (sugar, pitch, polymers, etc.), which require pyrolysis to form a coating material. Some nitrogen-containing polymers are often used for pyrolysis to produce nitrogen-containing carbon sources, and numerous experimental and theoretical studies have demonstrated that nitrogen-doped amorphous carbon has higher conductivity and ion mobility than the original carbon material. The nitrogen doped in the carbon source not only acts as an electron donor, but also provides electron carriers, which can enhance electron conduction between the carbon layer and the adjacent silicon particles. However, the common nitrogen source is expensive and even toxic, which hinders the environmental protection and mass production, and the natural biomass nitrogen-containing carbon source has become an important research direction. Disclosure of Invention In view of the above, the present invention aims to provide a method for preparing a silicon-carbon anode material coated with mixed biomass carbon. In order to achieve the above purpose, the technical scheme of the invention is as follows: The silicon-based anode material coated by the mixed biomass carbon is characterized by being prepared by the following steps: (1) Mixing and grinding prolamin, glutenin and high-activity yeast according to the mass ratio of 1:x (1+x)/2 to obtain mixed powder I; (2) Adding silicon negative electrode powder into the mixed powder I, further grinding, adding a proper amount of deionized water, and performing ultrasonic dispersion to obtain a uniform mixed solution; (3) Drying the obtained uniform mixed solution to obtain a precursor material; (4) And carrying out high-temperature annealing treatment on the obtained precursor material to obtain the silicon-based anode material coated with the mixed biomass carbon. Preferably, in the step (1), x in the ratio of 1:x (1+x)/2 is 0.5-2. Preferably, in the step (2), the addition amount of the silicon negative electrode is determined by a silicon-carbon mass ratio, and the silicon-carbon mass ratio is 0.2-10. Preferably, in step (3), the drying method is freeze drying or spray drying until the material is in powder form. Preferably, in the step (4), the high-temperature annealing device is a tube furnace, argon is introduced in the annealing process, and the air flow is 50-300 cfm. Preferably, in the step (4), the high-temperature annealing temperature is 600-800 ℃ and the annealing time is 0.5-5 h. The invention discloses a lithium ion battery, and a negative electrode material of the battery adopts a silicon-based negative electrode material coated by mixed biomass carbon. Advantageous effects The invention provides a preparation method of a silicon-based anode material coated by mixed biomass carbon, wherein the biomass carbon is mainly derived from prolamin, glutenin and high-activity yeast. The prolamine and the glutenin form a reticular structure when