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CN-118145624-B - Preparation method and application of fluorocarbon material with high fluorocarbon ratio

CN118145624BCN 118145624 BCN118145624 BCN 118145624BCN-118145624-B

Abstract

The invention discloses a preparation method and application of a fluorocarbon material with high fluorocarbon ratio, which belong to the field of fluorocarbon material preparation, and comprise the following steps of S1, crushing tea stems, filtering and separating the crushed tea stems, S2, stirring the dried crushed tea stems and acid liquor for 2-4h at 100-130 ℃, cleaning the crushed tea stems until the pH value of an aqueous solution is 6-8, S3, heating the crushed tea stems to 140-160 ℃ in an inert gas atmosphere, keeping the temperature for 1.5-2.5h, carbonizing for 2-4h at 1100-1400 ℃, cooling to obtain a pyrolytic carbon material, S4, washing the pyrolytic carbon material to be neutral, grinding the pyrolytic carbon material into powder after drying, S5, putting the powder into a container, vacuumizing, introducing fluorine-containing gas, keeping the pressure of 0.3-0.7MPa, reacting for 12-72h at 280-360 ℃, and cooling to room temperature after the reaction is finished to obtain the fluorocarbon material with high fluorocarbon ratio. The invention takes tea stems as raw materials, and prepares the fluorocarbon material with high fluorocarbon ratio by using a high-pressure low-temperature fluorination process, wherein the fluorocarbon ratio is more than or equal to 1.0.

Inventors

  • CHEN HUIXIN
  • YUE HONGJUN
  • YAN KE
  • ZOU YAN

Assignees

  • 中国科学院福建物质结构研究所

Dates

Publication Date
20260505
Application Date
20231020

Claims (9)

  1. 1. The preparation method of the fluorocarbon material with the high fluorocarbon ratio is characterized by comprising the following steps of: s1, crushing tea stems, filtering and separating out the crushed tea stems, and cleaning and drying; S2, stirring the dried crushed tea stems and acid liquor for 2-4 hours at 100-130 ℃, and then cleaning the crushed tea stems until the pH value of the aqueous solution is 6-8; S3, crushing the tea stems cleaned in the step S2, heating to 140-160 ℃ in an inert gas atmosphere, maintaining the temperature for 1.5-2.5h, carbonizing for 2-4h at 1100-1400 ℃, and cooling to obtain pyrolytic carbon materials; S4, washing the pyrolytic carbon material obtained in the step S3 to be neutral, drying and grinding into powder; S5, placing the powder obtained in the step S4 into a container, vacuumizing, introducing fluorine-containing gas, keeping the pressure at 0.3-0.7MPa, reacting for 12-72h at 280-360 ℃, and cooling to room temperature after the reaction is finished to obtain the fluorocarbon material with high fluorocarbon ratio.
  2. 2. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S1: Crushing by adopting a wall breaking machine; filtering with a sieve with 0.2-0.5mm mesh; and (5) cleaning by adopting deionized water and ethanol.
  3. 3. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S2: The acid liquor is hydrochloric acid with the concentration of 0.8-1.2 mol/L; And cleaning the crushed tea stems by deionized water.
  4. 4. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S3: The inert gas is one or a combination of more of nitrogen, argon, neon and helium.
  5. 5. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S3: the crushed tea stalks are heated to 140-160 ℃ at a heating rate of 4-6 ℃ per minute under the flowing inert gas atmosphere.
  6. 6. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S4: The drying temperature is 70-90 ℃, the drying time is 2-4h, and deionized water is adopted for washing.
  7. 7. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein in step S5: the powder reacts with fluorine-containing gas in a fluorination furnace, wherein the fluorine-containing gas is one or a combination of more of xenon difluoride, nitrogen trifluoride, fluorine gas, boron trifluoride and fluorine-argon mixed gas.
  8. 8. The method for producing a fluorocarbon material having a high fluorocarbon ratio as claimed in claim 1, wherein: further comprising S6: grinding the fluorocarbon material with high fluorocarbon ratio obtained in the step S5 to 30-250 meshes.
  9. 9. Use of a high fluorocarbon ratio fluorocarbon material prepared by the method of any one of claims 1 to 8 in a battery positive electrode material.

Description

Preparation method and application of fluorocarbon material with high fluorocarbon ratio Technical Field The invention belongs to the field of preparation of fluorocarbon materials, and particularly relates to a preparation method and application of a fluorocarbon material with a high fluorocarbon ratio. Background Carbon fluoride is a carbon derivative having a C-F bond formed by fluorination of a carbonaceous material and a fluorinating agent under certain conditions. The chemical formula of the fluorocarbon is CFx, wherein x is the atomic ratio of fluorocarbon, and is generally between 0 and 1. The fluorocarbon material is one of the novel carbon-based material research hot spots with high technology, high performance and high benefit internationally, and has excellent performance, unique quality and a plurality of distinctive performances. Fluorocarbon materials were first widely used in the field of solid lubricants, and in recent years, applications as lithium primary batteries have been further developed. The carbon source and the fluorination process are two important factors influencing the performance of the carbon fluoride, so that the selection of the carbon source, the structural design of the biomass carbon material and the fluorination process technology are key and indispensable for preparing the high-performance biomass carbon-based carbon fluoride cathode material. The existing biomass carbon materials have the defects of quite different structural morphology, good performance, poor fluorination effect, uneven fluorination degree of fluorinated products and the like, so that the fluorinated biomass carbon materials developed by the prior art are difficult to achieve excellent performance and stable preparation. For example, patent CN 110875475A discloses a method for preparing biomass carbon by using fruit shells and then carrying out fluorination by a fluorination process, the yield of the prepared material is low, and the requirement of kilogram level cannot be met, which is related to the biomass carbon material used by the method and the fluorination process. The tea stalk is leaf stalk of tea tree. At present, china does not have a competitive fluorocarbon cathode material product, mainly the prepared fluorocarbon has low degree of fluorination and low specific energy. Many biomass hard carbons prepared at present have poor performance, have no higher specific surface area and proper pore diameter, so that the traditional low-temperature low-pressure fluorination process cannot be used for preparing the fluorocarbon materials with high degree of fluorination, and the degree of fluorination (CFx) x is more than or equal to 1.0, which is generally considered to be higher. Disclosure of Invention The invention aims to provide a preparation method and application of a fluorocarbon material with high fluorocarbon ratio, so as to overcome at least one defect in the prior art. To achieve the purpose, the invention adopts the following technical scheme: The invention provides a preparation method of a fluorocarbon material with high fluorine-carbon ratio, which comprises the following steps of S1, crushing tea stems, filtering and separating out the crushed tea stems, cleaning and drying, S2, stirring the crushed tea stems and acid liquor for 2-4h at 100-130 ℃, cleaning the crushed tea stems until the pH value of an aqueous solution is 6-8, S3, heating the crushed tea stems cleaned in the step S2 to 140-160 ℃ in an inert gas atmosphere, keeping the temperature for 1.5-2.5h, carbonizing at 1100-1400 ℃ for 2-4h, cooling to obtain a pyrolytic carbon material, S4, washing the pyrolytic carbon material obtained in the step S3 to neutrality, drying and grinding the pyrolytic carbon material into powder, S5, placing the powder obtained in the step S4 into a container, vacuumizing, introducing fluorine-containing gas, keeping the pressure of 0.3-0.7MPa, reacting for 12-72h at 280-360 ℃, and cooling to room temperature after the reaction is finished to obtain the fluorocarbon material with high fluorine-carbon ratio. Preferably, in the step S1, a wall breaking machine is adopted for crushing, a screen with a screen mesh of 0.2-0.5mm is adopted for filtering, and deionized water and ethanol are adopted for cleaning. Preferably, in the step S2, the acid liquor is 0.8-1.2mol/L hydrochloric acid, and deionized water is used for cleaning the crushed tea stems. Preferably, in the step S3, the inert gas is one or a combination of more of nitrogen, argon, neon and helium. Preferably, in step S3, the crushed tea stalks are heated to 140-160 ℃ at a heating rate of 4-6 ℃ per minute under a flowing inert gas atmosphere. Preferably, in the step S4, the drying temperature is 70-90 ℃, the drying time is 2-4 hours, and deionized water is used for washing. Preferably, in step S5, the powder is reacted with a fluorine-containing gas in a fluorination furnace, wherein the fluorine-containing gas is one or a combination