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CN-121976328-A - Preparation method and application of porous carbon fiber network based on polymer precursor

CN121976328ACN 121976328 ACN121976328 ACN 121976328ACN-121976328-A

Abstract

The invention discloses a preparation method of a porous carbon fiber network based on a polymer precursor, which is characterized by comprising the following steps of S1, preparing a gas-phase polymer precursor, directly conveying the gas-phase polymer precursor through carrier gas, S2, receiving the conveyed gas-phase polymer precursor, carrying out electrostatic spinning treatment to obtain a target product, S3, carbonizing the target product to form a porous carbon fiber network with self-supporting characteristics, preparing the polymer precursor through a gas-phase polymer precursor preparation unit, forming a fiber precursor through an electrostatic spinning unit, carbonizing the fiber precursor through a carbonization treatment unit to generate a porous carbon fiber network, and finally carrying the self-supporting porous carbon fiber network through a silicon deposition substrate.

Inventors

  • MENG FANCHANG
  • WANG MENG
  • CHEN WEIDONG

Assignees

  • 浙江嘉兴星汉纳米科技有限公司

Dates

Publication Date
20260505
Application Date
20251224

Claims (9)

  1. 1. A method for preparing a porous carbon fiber network based on a polymer precursor, the method comprising the steps of: s1, preparing a gas-phase polymer precursor, and directly conveying the gas-phase polymer precursor through carrier gas; s2, receiving the conveyed gas-phase polymer precursor, and carrying out electrostatic spinning treatment to obtain a target product; and S3, carbonizing the target product to form a porous carbon fiber network with self-supporting characteristics.
  2. 2. The method for preparing a porous carbon fiber network based on a polymer precursor according to claim 1, wherein the preparation of the polymer precursor in the step S1 comprises the following sub-steps: S11, selecting a polymer precursor material, wherein the polymer precursor material is at least one of polyacrylonitrile, polyimide or polyvinyl alcohol; And S12, heating the selected polymer precursor material to 250-350 ℃ and completely gasifying to form a gaseous polymer precursor.
  3. 3. The preparation method of the porous carbon fiber network based on the polymer precursor according to claim 1, wherein in the step S2, the electrostatic spinning is performed at a spinning voltage of 10-30 kV, a receiving distance of 10-15 cm, a spinning solution flow rate of 0.5-1.5 mL/h, an ambient temperature of 15-35 ℃, an ambient humidity of 30-60%, a fiber diameter of 100-500 nm and a porosity of 60-80%.
  4. 4. The method for preparing the porous carbon fiber network based on the polymer precursor according to claim 1, wherein during the carbonization treatment in the step S3, the carbonization atmosphere is one of nitrogen and argon, the carbonization temperature is 800-1400 ℃, the carbonization time is 1-1.5 h, and the heating rate in the carbonization process is 2-10 ℃ per minute.
  5. 5. The preparation method of the porous carbon fiber network based on the polymer precursor according to claim 1, wherein the porous carbon fiber network has a porosity of 60-90% and a specific surface area of 500-1500 m2/g.
  6. 6. The method for preparing the porous carbon fiber network based on the polymer precursor according to claim 1, wherein the target product is pre-oxidized between the step S2 and the step S3 to stabilize the fiber structure, wherein the pre-oxidation temperature is 150-300 ℃, and the atmosphere is air or nitrogen-oxygen mixed gas.
  7. 7. The preparation method of the porous carbon fiber network based on the polymer precursor according to claim 6, wherein in the pre-oxidation treatment, the temperature rising rate of the pre-oxidation treatment is 1-5 ℃ per minute, and the heat preservation time is 30-120 min.
  8. 8. The application of a porous carbon fiber network based on a polymer precursor is characterized in that the porous carbon fiber network is prepared by the preparation method of the porous carbon fiber network based on the polymer precursor according to any one of claims 1-7, and a silicon/carbon composite material is prepared by placing a substrate bearing the porous carbon fiber network in a reaction cavity, introducing silicon source gas and reducing gas, and carrying out deposition reaction for 1-4 h at the temperature of 600-900 ℃.
  9. 9. The application of the porous carbon fiber network based on the polymer precursor according to claim 8, wherein the silicon source gas is silane or silicon tetrachloride, the reducing gas is hydrogen, and the molar ratio of the silicon source gas to the reducing gas is 1:3-1:8.

Description

Preparation method and application of porous carbon fiber network based on polymer precursor Technical Field The invention relates to the technical field of nano materials, in particular to a preparation method and application of a porous carbon fiber network based on a polymer precursor. Background In the field of lithium ion battery anode materials, silicon is considered as an ideal choice for next generation anode materials due to its high theoretical specific capacity (about 4200 mAh/g). However, silicon has serious volume expansion (about 300%) during charge and discharge, resulting in pulverization of an electrode structure and falling of active materials, thereby remarkably reducing the cycle stability and coulombic efficiency of the battery. In the prior art, a silicon material and a carbon material are generally compounded to relieve the volume expansion problem, but the traditional silicon deposition substrate is complex in preparation process, an adhesive and a conductive agent are required to be additionally added, the bonding force between the substrate and the silicon material is weak, and the practical application requirement of the high-performance silicon-based negative electrode material is difficult to meet. In addition, the existing preparation methods of carbon fiber base materials mostly adopt a liquid-phase spinning or template method, and have the problems of low porosity, insufficient specific surface area, poor mechanical strength and the like, so that the silicon material has limited load capacity and the volume expansion of silicon cannot be effectively buffered. Therefore, how to develop a simple and efficient porous carbon fiber network preparation method, which can be directly used as a self-supporting silicon deposition substrate to improve the electrochemical performance of silicon-based materials is a technical problem to be solved in the field. Disclosure of Invention The invention aims to provide a preparation method and application of a porous carbon fiber network based on a polymer precursor, and aims to solve the problems of low porosity, insufficient specific surface area, lack of self-supporting property and the like of the existing carbon fiber material, which are proposed in the background art. In order to achieve the aim, the invention provides the following technical scheme that the preparation method of the porous carbon fiber network based on the polymer precursor is characterized by comprising the following steps of: s1, preparing a gas-phase polymer precursor, and directly conveying the gas-phase polymer precursor through carrier gas; s2, receiving the conveyed gas-phase polymer precursor, and carrying out electrostatic spinning treatment to obtain a target product; and S3, carbonizing the target product to form a porous carbon fiber network with self-supporting characteristics. Preferably, the preparation of the polymer precursor in the step S1 includes the following sub-steps: S11, selecting a polymer precursor material, wherein the polymer precursor material is at least one of polyacrylonitrile, polyimide or polyvinyl alcohol; And S12, heating the selected polymer precursor material to 250-350 ℃ and completely gasifying to form a gaseous polymer precursor. Preferably, in the step S2, the electrostatic spinning is performed at a spinning voltage of 10-30 kV, a receiving distance of 10-15 cm, a spinning solution flow rate of 0.5-1.5 mL/h, an ambient temperature of 15-35 ℃, an ambient humidity of 30-60%, a fiber diameter of 100-500 nm, and a porosity of 60-80%. Preferably, during the carbonization in the step S3, the carbonization atmosphere is one of nitrogen and argon, the carbonization temperature is 800-1400 ℃, the carbonization time is 1-1.5 h, and the temperature rising rate in the carbonization process is 2-10 ℃ per minute. Preferably, the porosity of the porous carbon fiber network is 60-90%, and the specific surface area is 500-1500 m2/g. Preferably, the target product is pre-oxidized between the step S2 and the step S3 to stabilize the fiber structure, wherein the pre-oxidation temperature is 150-300 ℃, and the atmosphere is air or nitrogen-oxygen mixed gas. Preferably, in the pre-oxidation treatment, the temperature rising rate of the pre-oxidation treatment is 1-5 ℃ per minute, and the heat preservation time is 30-120 minutes. The application of the porous carbon fiber network based on the polymer precursor is that a porous carbon fiber network bearing substrate is placed in a reaction cavity, silicon source gas and reducing gas are introduced, and deposition reaction is carried out for 1-4 hours at the temperature of 600-900 ℃, so that the silicon/carbon composite material is prepared. Preferably, the silicon source gas is silane or silicon tetrachloride, the reducing gas is hydrogen, and the molar ratio of the silicon source gas to the reducing gas is 1:3-1:8. The invention has the beneficial effects that: 1. Preparing a polymer precursor throug