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CN-121516861-B - Preparation method of porous carbon based on aerogel method, porous carbon and application thereof

CN121516861BCN 121516861 BCN121516861 BCN 121516861BCN-121516861-B

Abstract

The invention provides a preparation method of porous carbon based on an aerogel method, porous carbon and application thereof, and belongs to the technical field of porous carbon material preparation. The preparation method comprises the steps of mixing polyhydroxy phenol, aromatic aldehyde, acrylamide, graphene oxide and lithium salt according to the mass ratio of 100:50-200:5-5:1-5, performing hydrothermal reaction at 100-200 ℃ for 1-6 hours and freeze-drying at 40 ℃ to obtain a hydrogel precursor, carbonizing the precursor in 500-800 ℃ organic heteroatom gas, mixing the intermediate with alkali according to 100:100-500 ℃, activating at 900-1100 ℃, and performing acid washing and drying to obtain the porous carbon. The product improves the conductivity by means of graphene, lithium salt and hetero atoms, and the aerogel method is large in aperture, has the characteristics of low impedance, high first efficiency and small charge-discharge expansion, and can be effectively applied to silicon-carbon materials.

Inventors

  • HU AIGUO
  • LIU RUIZHENG
  • CHEN GONG
  • LI SHUZHEN

Assignees

  • 国科炭美新材料(湖州)有限公司

Dates

Publication Date
20260512
Application Date
20260115

Claims (9)

  1. 1. The preparation method of the porous carbon based on the aerogel method is characterized by comprising the following steps: uniformly mixing polyhydroxy phenol, aromatic aldehyde, acrylamide, graphene oxide and a lithium salt compound, and then performing hydrothermal reaction to obtain a hydrothermal product; carbonizing the hydrogel precursor under organic heteroatom gas to obtain an intermediate material; Uniformly mixing the intermediate material with an alkali compound, and then carrying out activation treatment to obtain an activated product; The acrylamide comprises one or more of N-methyl-2-acrylamide, N-isopropyl methacrylamide, N-butoxy methacrylamide or N, N' -methylenebisacrylamide; The organic heteroatom gas comprises one or more of ethylene oxide, methylamine, dimethyl ether, or methyl chloride.
  2. 2. The preparation method according to claim 1, wherein the mass ratio of the polyhydric phenol, the aromatic aldehyde, the acrylamide, the graphene oxide and the lithium salt compound is 100 (50-200): (5-30): (1-5): (1-5).
  3. 3. The preparation method according to claim 1, wherein the hydrothermal reaction is carried out at a temperature of 100-200 ℃ for a reaction time of 1-6 hours.
  4. 4. The method of preparing as claimed in claim 1, wherein carbonizing the hydrogel precursor under an organic heteroatom gas to obtain an intermediate material comprises: heating the hydrogel precursor to 500-800 ℃, introducing organic heteroatom gas according to the flow rate of 100-500mL/min, and carbonizing for 60-600min in the organic heteroatom gas environment to obtain an intermediate material.
  5. 5. The method of claim 1, wherein the polyhydric phenol comprises one or more of catechol, hydroquinone, resorcinol, phloroglucinol, or t-butylcatechol; the aromatic aldehyde comprises one or more of benzaldehyde, salicylaldehyde, cinnamaldehyde, amyl cinnamaldehyde, 4-hydroxy-3-methoxybenzaldehyde or p-methoxybenzaldehyde; the lithium salt compound comprises one or more of lithium acetate, lithium oxalate, lithium lactate, lithium triflate, lithium stearate or lithium benzoate.
  6. 6. The method of preparation of claim 1, wherein the alkali compound comprises one or more of potassium hydroxide, potassium carbonate, sodium hydroxide, or magnesium hydroxide; the mass ratio of the intermediate material to the alkali compound is 100 (100-500).
  7. 7. The method according to claim 1, wherein the activation treatment is performed at a temperature of 900 to 1100 ℃ for a time of 1 to 6 hours.
  8. 8. A porous carbon produced by the production method according to any one of claims 1 to 7.
  9. 9. Use of the porous carbon of claim 8 in a silicon carbon material.

Description

Preparation method of porous carbon based on aerogel method, porous carbon and application thereof Technical Field The invention relates to the technical field of porous carbon material preparation, in particular to a preparation method of porous carbon based on an aerogel method, porous carbon and application thereof. Background The porous carbon is used as a key material for preparing the silicon-carbon composite material, and the preparation method mainly comprises a physical activation method (steam, carbon dioxide and the like) and a chemical activation method (KOH and the like). However, the porous carbon prepared by the method has poor electronic conductivity and many defects, so that the porous carbon material has low first efficiency and large powder resistance, and the rate capability is poor in the application process. Although researchers have improved electron conductivity and reduced defects by doping or depositing conductive materials with heteroatoms, there is some improvement in the first-time efficiency and reduction in powder resistance. However, the porous carbon material prepared by the conventional physical or chemical activation method still has the problems of more defects, uneven pore size distribution and the like, and the first efficiency of the porous carbon material still needs to be improved. Disclosure of Invention In order to improve the first efficiency and reduce the impedance of the porous carbon, the invention is based on an aerogel method, graphene oxide and lithium salt compounds are doped in a phenolic resin precursor, and the porous carbon with large aperture, low expansion and high conductivity is obtained by combining hydrothermal, carbonization and chemical activation, so that the first efficiency of the porous carbon is improved. The invention aims at providing a preparation method for preparing porous carbon based on an aerogel method, which comprises the following steps: uniformly mixing polyhydroxy phenol, aromatic aldehyde, acrylamide, graphene oxide and a lithium salt compound, and then performing hydrothermal reaction to obtain a hydrothermal product; carbonizing the hydrogel precursor under organic heteroatom gas to obtain an intermediate material; And (3) uniformly mixing the intermediate material with an alkali compound, performing activation treatment to obtain an activated product, and performing acid washing and drying on the activated product to obtain the porous carbon. Preferably, the mass ratio of the polyhydroxy phenol to the aromatic aldehyde to the acrylamide to the graphene oxide to the lithium salt compound is 100 (50-200): 5-30): 1-5. Preferably, the temperature of the hydrothermal reaction is 100-200 ℃ and the reaction time is 1-6h. Preferably, the carbonizing the hydrogel precursor under the organic heteroatom gas to obtain an intermediate material includes: heating the hydrogel precursor to 500-800 ℃, introducing organic heteroatom gas according to the flow rate of 100-500mL/min, and carbonizing for 60-600min in the organic heteroatom gas environment to obtain an intermediate material. Preferably, the polyhydric phenol comprises one or more of catechol, hydroquinone, resorcinol, phloroglucinol, or t-butylcatechol; the aromatic aldehyde comprises one or more of benzaldehyde, salicylaldehyde, cinnamaldehyde, amyl cinnamaldehyde, 4-hydroxy-3-methoxybenzaldehyde or p-methoxybenzaldehyde; The acrylamide comprises one or more of N-methyl-2-acrylamide, N-isopropyl methacrylamide, N-butoxy methacrylamide or N, N' -methylenebisacrylamide; the lithium salt compound comprises one or more of lithium acetate, lithium oxalate, lithium lactate, lithium triflate, lithium stearate or lithium benzoate. Preferably, the organic heteroatom gas comprises one or more of ethylene oxide, methylamine, dimethyl ether or methyl chloride. Preferably, the alkali compound comprises one or more of potassium hydroxide, potassium carbonate, sodium hydroxide or magnesium hydroxide; the mass ratio of the intermediate material to the alkali compound is 100 (100-500). Preferably, the temperature of the activation treatment is 900-1100 ℃, and the time of the activation treatment is 1-6h. The second object of the invention is to provide a porous carbon prepared by the preparation method. The invention further aims to provide application of the porous carbon to silicon-carbon materials. The invention has the beneficial effects that: According to the preparation method, graphene oxide and lithium salt compounds are doped in phenols and aldehydes compounds, and graphene/lithium salt doped porous carbon is prepared through hydrothermal reaction pretreatment, and the graphene/lithium salt doped porous carbon has the advantages of high electronic conductivity, high ionic conductivity of lithium salt compounds, capability of reducing defects and irreversible capacity of the porous carbon, improving first efficiency and diffusion coefficient thereof and improving rate capability, and me