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CN-121974401-A - Preparation method of carbon fiber-tungsten sulfide-graphene compound for sodium ion battery

CN121974401ACN 121974401 ACN121974401 ACN 121974401ACN-121974401-A

Abstract

The embodiment of the specification discloses a preparation method of a carbon fiber-tungsten sulfide-graphene composite for a sodium ion battery, which comprises the steps of S1, dissolving sodium tungstate, hydroxylamine hydrochloride, thiourea and sodium hydroxide in deionized water, uniformly stirring to prepare a reaction solution, S2, mixing the reaction solution obtained in the step S1 with carbon fibers and graphene in a reaction kettle, performing hydrothermal reaction at a constant temperature, S3, filtering, cleaning and drying a product obtained in the step S2 to obtain a composite precursor, and S4, calcining the composite precursor at 800-950 ℃ in an inert gas atmosphere to obtain the carbon fiber-tungsten sulfide-graphene composite.

Inventors

  • WANG YAOHUI
  • XIA YANGFENG
  • ZHENG ZHE
  • SUN YANLI
  • ZHOU YOUJIE
  • CHEN JINMAO
  • HUANG LONG
  • WANG XUDONG
  • XU WANLI
  • SU XING
  • AN GAOJUN
  • XU XIMENG

Assignees

  • 军事科学院系统工程研究院军事新能源技术研究所

Dates

Publication Date
20260505
Application Date
20251229

Claims (9)

  1. 1. The preparation method of the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery is characterized by comprising the following steps of: S1, dissolving sodium tungstate, hydroxylamine hydrochloride, thiourea and sodium hydroxide in deionized water, and uniformly stirring to prepare a reaction solution; S2, mixing the reaction liquid obtained in the step S1 with carbon fibers and graphene in a reaction kettle, and performing hydrothermal reaction at a constant temperature; S3, filtering, cleaning and drying the product obtained in the step S2 to obtain a composite material precursor; And S4, calcining the composite material precursor at 800-950 ℃ in an inert gas atmosphere to obtain the carbon fiber-tungsten sulfide-graphene composite material.
  2. 2. The method for preparing the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery according to claim 1, wherein in the reaction solution in the step S1, the concentration of sodium tungstate is 0.05-0.2 mol/L, the concentration of hydroxylamine hydrochloride is 0.1-0.6 mol/L, the concentration of sodium hydroxide is 0.01-0.2 mol/L, and the concentration of thiourea is 0.1-0.9 mol/L.
  3. 3. The method for preparing the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery according to claim 1, wherein the hydrothermal reaction in the step S2 is performed under the pressure of 1.5-4.0 MPa, and the reaction temperature is a constant temperature of 180-240 ℃.
  4. 4. The method for preparing the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery according to any one of claims 1-3, wherein the method further comprises the step of repeating the reaction step after the step S3, wherein the step of repeating the reaction step is carried out for 1-5 times after the step of mixing and reacting the composite material precursor with the newly prepared reaction liquid in the step S1 and then washing and drying the reaction liquid.
  5. 5. The carbon fiber-tungsten sulfide-graphene composite material is characterized by being prepared by the preparation method of the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery according to any one of claims 1-4.
  6. 6. The carbon fiber-tungsten sulfide-graphene composite material according to claim 5, wherein tungsten sulfide is 100-200 nm nanoparticles, and the tungsten sulfide and graphene are anchored on the surface of the carbon fiber.
  7. 7. The carbon fiber-tungsten sulfide-graphene composite material according to claim 5 or 6, wherein the density of the carbon fiber is 1.7-1.9 g/.
  8. 8. A negative electrode for a sodium ion battery, characterized by comprising the carbon fiber-tungsten sulfide-graphene composite material according to any one of claims 5 to 7.
  9. 9. A sodium ion battery comprising a carbon fiber-tungsten sulfide-graphene composite material prepared by the preparation method of any one of claims 1 to 4, or a negative electrode for a sodium ion battery prepared by the carbon fiber-tungsten sulfide-graphene composite material of any one of claims 5 to 7.

Description

Preparation method of carbon fiber-tungsten sulfide-graphene compound for sodium ion battery Technical Field The invention relates to the technical field of battery materials, in particular to a preparation method of a carbon fiber-tungsten sulfide-graphene compound for a sodium ion battery. Background In recent years, the energy storage field has increasingly stringent requirements for secondary batteries with abundant resources and low cost. Sodium ion batteries and potassium ion batteries, which are similar to lithium ion battery energy storage mechanisms but have wider raw material sources, have become research hotspots for new generation electrochemical energy storage technologies. Electrode materials, particularly negative electrode materials, are one of the key factors in determining the performance of sodium/potassium ion batteries. Currently, researchers have explored a variety of negative electrode material systems, mainly including carbon-based materials (e.g., graphite, hard carbon), alloy-based materials, metal oxides, phosphides, organic compounds, and the like. Among them, metal sulfides are attracting attention due to their unique physicochemical properties, and are considered as extremely potential candidates for negative electrode materials, which are mainly due to the advantages of (1) relatively good reaction kinetics in which the bond energy of the metal-sulfur bond (M-S) is generally lower than that of the metal-oxygen bond (M-O) compared with the corresponding metal oxide, which makes the bonding easier to break and recombine in electrochemical reactions, facilitating the diffusion and reaction of alkali metal ions (Na +/K+). (2) The metal sulfide can store ions through various mechanisms including intercalation reaction, conversion reaction and even alloying reaction, and meanwhile, the metal sulfide is accompanied by remarkable pseudocapacitance behavior, and the mechanisms jointly contribute to the higher theoretical specific capacity. (3) Suitable interlayer channels are formed by a plurality of lamellar metal sulfides with larger interlayer spacing, which provide convenient channels for reversible intercalation and deintercalation of sodium/potassium ions with larger volume and are beneficial to realizing rapid ion transmission. Nevertheless, metal sulfide cathodes still face significant challenges on the way to practical use. First, its intrinsic electron conductivity is still generally low, limiting the improvement of the rate capability. Second, during charge and discharge, particularly when the conversion reaction occurs, the material undergoes significant volume expansion/contraction, resulting in pulverization of the electrode structure, separation of the active material from the current collector, and rapid decay of capacity. Disclosure of Invention The invention provides a preparation method of a carbon fiber-tungsten sulfide-graphene compound for a sodium ion battery, which aims to solve the problems of poor conductivity and ion diffusivity, slow interface/surface reaction kinetics and obvious volume expansion in the sodium ion storage process of the existing metal sulfide-based electrode material. In order to achieve the above object, the present invention provides the following solutions: the preparation method of the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery comprises the following steps: S1, dissolving sodium tungstate, hydroxylamine hydrochloride, thiourea and sodium hydroxide in deionized water, and uniformly stirring to prepare a reaction solution; S2, mixing the reaction liquid obtained in the step S1 with carbon fibers and graphene in a reaction kettle, and performing hydrothermal reaction at a constant temperature; S3, filtering, cleaning and drying the product obtained in the step S2 to obtain a composite material precursor; And S4, calcining the composite material precursor at 800-950 ℃ in an inert gas atmosphere to obtain the carbon fiber-tungsten sulfide-graphene composite material. Further, in the reaction solution in the step S1, the concentration of sodium tungstate is 0.05-0.2 mol/L, the concentration of hydroxylamine hydrochloride is 0.1-0.6 mol/L, the concentration of sodium hydroxide is 0.01-0.2 mol/L, and the concentration of thiourea is 0.1-0.9 mol/L. Further, the hydrothermal reaction in the step S2 is performed under the pressure of 1.5-4.0 MPa, and the reaction temperature is a constant temperature of 180-240 ℃. Further, the method further comprises a repeated reaction step after the step S3, wherein the composite material precursor and the newly prepared reaction liquid in the step S1 are mixed for reaction, and then are washed and dried, and the repeated reaction step is carried out for 1-5 times. The invention also provides a carbon fiber-tungsten sulfide-graphene composite material, which is prepared by the preparation method of the carbon fiber-tungsten sulfide-graphene composite for the sodium ion battery.