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CN-121983518-A - In-situ growth construction three-dimensional porous carbon package V2O5Carbon fiber electrode of (2), preparation method and application thereof

CN121983518ACN 121983518 ACN121983518 ACN 121983518ACN-121983518-A

Abstract

The invention discloses a carbon fiber electrode for constructing a three-dimensional porous carbon package V 2 O 5 through in-situ growth, and a preparation method and application thereof, belongs to the technical field of aluminum ion battery anode materials, and aims to solve the technical problem that the kinetics of intercalation and deintercalation of AlCl 4 -in the inside of a polyacrylonitrile (Pan) based carbon fiber is blocked due to disordered graphite structure, and further the polyacrylonitrile (Pan) based carbon fiber cannot be used as an effective electrode material for an aluminum ion battery system. According to the invention, an in-situ growth technology is adopted, a three-dimensional porous carbon matrix is grown on the surface of the carbon fiber, and then an orthorhombic vanadium pentoxide (V 2 O 5 ) nanomaterial which has high theoretical specific capacity and can realize high-current charge and discharge is packaged in the three-dimensional porous carbon matrix to prepare the V 2 O 5 -based carbon fiber electrode. The electrode not only effectively lightens the electrostatic interaction between Al 3+ ions and crystal lattices, but also fully combines the structural advantage of carbon fibers and the energy storage performance of V 2 O 5 , remarkably improves the energy storage effect of the aluminum ion battery, and provides a new effective scheme for the development of electrode materials of the aluminum ion battery.

Inventors

  • YE JINRUI
  • WANG JINRUI

Assignees

  • 北京理工大学

Dates

Publication Date
20260505
Application Date
20251231

Claims (8)

  1. 1. The method for constructing the carbon fiber electrode of the three-dimensional porous carbon encapsulation V 2 O 5 by in-situ growth is characterized by comprising the following specific steps: S1, placing carbon fibers in a Soxhlet extraction device, adding an organic solvent for reflux treatment, then washing the carbon fibers with deionized water, and drying; S2, adding starch and KOH into deionized water, stirring and mixing, and then transferring the mixed solution into an oven for heat preservation to form a sol-gel solution; s3, soaking the carbon fiber treated in the step S1 in the sol-gel solution, taking out and drying, putting the dried carbon fiber in a tubular furnace under nitrogen atmosphere, heating to a target temperature, preserving heat, then cleaning and drying to obtain the 3D reticular porous carbon matrix coating flexible carbon fiber; and S4, adding the triisopropoxy vanadium oxide into isopropanol, stirring and mixing to obtain a mixed solution, immersing the 3D reticular porous carbon substrate coating flexible carbon fiber prepared in the step S3 into the mixed solution, heating for reaction, washing a sample after the reaction is finished, drying, and annealing the dried sample in air to obtain the carbon fiber electrode of the three-dimensional porous carbon encapsulation V 2 O 5 .
  2. 2. The method according to claim 1, wherein in step S1, the time of the reflow treatment is 24 to 48 hours, the time of the deionized water rinse is 6 to 12 hours, and the drying temperature is 60 to 80 ℃.
  3. 3. The method according to claim 1, wherein in the step S2, the mass ratio of the starch to the KOH is (1-4), the mass volume ratio of the starch to the deionized water is (1-4) g (10-40) mL, the heat preservation temperature of the oven is 50-70 ℃, and the heat preservation time is 20-30 hours.
  4. 4. The method according to claim 1, wherein in the step S3, the temperature of the sol-gel solution is 75-85 ℃ and the soaking time is 1-6 hours, the drying temperature after taking out is 70-90 ℃ and the drying time is 20-30 hours, the target temperature of the tube furnace is 550-650 ℃, the heating rate is 2-5 ℃ min-1 and the heat preservation time is 1-3 hours, and the drying temperature after cleaning is 70-90 ℃ and the drying time is 20-30 hours.
  5. 5. The method according to claim 1, wherein in the step S4, the volume ratio of the triisopropyloxy vanadium oxide to the isopropanol is (0.05-0.15): (35-45), the stirring time is 25-35 minutes, the reaction temperature is 170-190 ℃, the reaction time is 10-15 hours, the annealing temperature in the air is 300-350 ℃, the annealing time is 1-3 hours, and the drying time is 20-24 hours.
  6. 6. A carbon fiber electrode of three-dimensional porous carbon package V 2 O 5 made by the method of any one of claims 1to 5.
  7. 7. The use of the carbon fiber electrode of the three-dimensional porous carbon package V 2 O 5 in an aluminum ion battery.
  8. 8. The application of the three-dimensional porous carbon packaging V 2 O 5 is characterized in that a carbon fiber electrode of the three-dimensional porous carbon packaging V 2 O 5 is used as an anode, a molybdenum sheet is used as an anode lug, conductive silver paste is used for pasting the molybdenum sheet on the carbon fiber electrode of the three-dimensional porous carbon packaging V 2 O 5 , an aluminum net is used as a cathode material, the lug is reserved, a glass fiber diaphragm is used as a diaphragm, an aluminum plastic film is used as a shell of an energy storage composite material, the carbon fiber electrode, the diaphragm and the cathode are sequentially stacked in sequence, packaged in the aluminum plastic film, electrolyte is poured into a glove box, and the three-dimensional porous carbon packaging V 2 O 5 is obtained after standing for 20-30 hours.

Description

Carbon fiber electrode for in-situ growth construction of three-dimensional porous carbon package V 2O5 and preparation method and application thereof Technical Field The invention belongs to the field of anode materials of aluminum ion batteries, and particularly relates to a carbon fiber electrode for constructing a three-dimensional porous carbon package V 2O5 through in-situ growth, and a preparation method and application thereof. Background Under the background of energy transformation and rapid increase of energy storage demands, the aluminum ion battery has the characteristics of high theoretical capacity, easily available raw materials, low cost, excellent safety performance and the like, and becomes an important research and development direction in the energy storage field, and the key core of performance improvement is breakthrough of the anode material. Carbon fiber is regarded as an ideal electrode material because of high specific surface area, excellent conductivity and mechanical stability, wherein polyacrylonitrile (Pan) based carbon fiber has the potential of becoming an electrode of an aluminum ion battery in theory because of mature preparation process and controllable cost and wide application in the field of composite materials. However, carbon fibers have the characteristics of smooth inert surfaces and disordered graphite structures, which results in the blocking of intercalation and deintercalation kinetics of key carriers AlCl 4 -inside the carbon fibers during the charge and discharge of the battery. In order to solve the problem, the invention provides a composite electrode preparation technology and selects an in-situ growth technology. The technology can obviously strengthen the interface binding force between the matrix and the active material by forming the chemically bonded active substance on the surface of the carbon fiber, simultaneously ensure the continuity of the microstructure, effectively avoid the problems of easy falling of the active substance and large interface resistance in the traditional physical mixing method, and provide a feasible path for improving the performance of the carbon fiber-based composite electrode. In the field of positive electrode active materials of aluminum ion batteries, orthorhombic vanadium pentoxide (V 2O5) has high theoretical specific capacity, can adapt to the requirement of high-current charge and discharge, and becomes an active component with great potential. However, V 2O5 has a problem that the electron conductivity is poor, and the layered structure is easy to collapse due to the intercalation/deintercalation of Al 3+ during the charge and discharge processes, so that the high performance requirement of the battery is difficult to meet when the battery is used alone. Therefore, the invention prepares the composite structure by in-situ growth means, grows the three-dimensional porous carbon matrix on the carbon fiber, and encapsulates the V 2O5 nano material in the three-dimensional porous carbon matrix. The porous carbon material provides a three-dimensional continuous conductive network on the surface of the carbon fiber, the network can effectively make up for the conductive defect caused by disordered structure of the Pan-based carbon fiber graphite, isolated conductive sites are connected into a through conductive channel, and meanwhile, the three-dimensional porous structure is beneficial to realizing uniform dispersion of V 2O5, avoiding particle aggregation, maximizing exposure of active sites and improving the utilization rate of the active material. Disclosure of Invention The invention aims to provide a carbon fiber electrode for constructing a three-dimensional porous carbon package V 2O5 through in-situ growth, and a preparation method and application thereof. Based on the above purpose, the invention adopts the following technical scheme: The method for constructing the carbon fiber electrode of the three-dimensional porous carbon encapsulation V 2O5 by in-situ growth comprises the following specific steps: S1, placing carbon fibers in a Soxhlet extraction device, adding an organic solvent for reflux treatment, then washing the carbon fibers with deionized water, and drying; S2, adding starch and KOH into deionized water, stirring and mixing, and then transferring the mixed solution into an oven for heat preservation to form a sol-gel solution; s3, soaking the carbon fiber treated in the step S1 in the sol-gel solution, taking out and drying, putting the dried carbon fiber in a tubular furnace under nitrogen atmosphere, heating to a target temperature, preserving heat, then cleaning and drying to obtain the 3D reticular porous carbon matrix coating flexible carbon fiber; and S4, adding the triisopropoxy vanadium oxide into isopropanol, stirring and mixing to obtain a mixed solution, immersing the 3D reticular porous carbon substrate coating flexible carbon fiber prepared in the step S3 into the mixed solution, he