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CN-118598115-B - Preparation method of iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball and application of iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball in sodium ion battery anode material

CN118598115BCN 118598115 BCN118598115 BCN 118598115BCN-118598115-B

Abstract

The invention relates to a preparation method of an iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball and application of the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball in a negative electrode material of a sodium ion battery, and belongs to the technical field of sodium ion batteries. The method comprises the steps of taking the prepared Prussian blue as a functional precursor, and carrying out one-step gas-phase sulfur-phosphorus treatment under an inert protective atmosphere to obtain the iron trisulfide-phosphorus-compound/nitrogen-doped carbon composite flower ball. Compared with the traditional FePS 3 preparation method, the preparation method provided by the invention is simple, convenient and controllable in morphology, and can obtain the flower-ball-shaped iron trisulfide phosphide/carbon composite material consisting of dispersed FePS 3 nano sheets without stripping, wherein the thickness of the FePS 3 nano sheets is 10-30 nm. The composite material has the advantage of being beneficial to the structure of the composite material, and when the composite material is used as a negative electrode material of a sodium ion battery, the iron trisulfide and phosphorus iron/nitrogen doped carbon composite flower ball has excellent electrochemical performance.

Inventors

  • YANG YEFENG
  • TANG TIANTIAN
  • Ren Gaoya
  • YAO ZHUJUN

Assignees

  • 浙江理工大学

Dates

Publication Date
20260505
Application Date
20240613

Claims (6)

  1. 1. The preparation method of the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball is characterized by comprising the following steps of: (1) Adding an iron source and polyvinylpyrrolidone into dilute hydrochloric acid, and uniformly stirring to obtain a solution A, wherein the mass ratio of the iron source to the polyvinylpyrrolidone is 1 (1-40), and the iron source is any one of potassium ferricyanide, potassium ferrocyanide and sodium ferrocyanide; (2) Carrying out solvothermal reaction on the solution A to obtain a blue suspension B, wherein the solvothermal reaction temperature is 80-120 ℃ and the reaction time is 10-36 hours; (3) Centrifuging and washing the blue suspension B, and drying to obtain blue powder C, wherein the mass ratio of the blue powder C to the phosphorus source to the sulfur source is 1:1 (1-5); (4) Grinding the blue powder C, the phosphorus source and the sulfur source uniformly to obtain mixed powder D; (5) And carrying out one-step gas-phase vulcanization and phosphating treatment on the powder D to obtain the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball which is composed of a plurality of nano-flakes and has the thickness of 10-30 nm.
  2. 2. The method of claim 1, wherein in the step (1), the concentration of the dilute hydrochloric acid is 0.05-0.2 mol/L.
  3. 3. The process according to claim 1, wherein in step (4), The phosphorus source is any one of sodium hypophosphite and red phosphorus; The sulfur source is any one of sulfur powder, thioacetamide and thiourea.
  4. 4. The preparation method of the catalyst according to claim 1, wherein in the step (5), the temperature of the one-step gas-phase vulcanization and phosphorization treatment is 300-700 ℃, the temperature rising rate is 1-10 ℃ per minute, and the heat preservation time is 1-6 hours; the one-step gas-phase sulfur-phosphating atmosphere is nitrogen, argon or argon-hydrogen.
  5. 5. The use of the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball obtained by the preparation method according to one of claims 1-4 as a negative electrode material of a sodium ion battery.
  6. 6. The sodium ion battery comprises a positive electrode, a negative electrode, a diaphragm and electrolyte, wherein the negative electrode comprises a negative electrode current collector and a negative electrode material layer coated on the surface of the current collector, and the negative electrode material layer comprises a negative electrode active substance, a conductive agent and a binder, and is characterized in that the negative electrode active substance is the iron trisulfide-phosphorus compound flower ball obtained by the preparation method according to one of claims 1-4.

Description

Preparation method of iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball and application of iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball in sodium ion battery anode material Technical Field The invention relates to the technical field of sodium ion batteries, in particular to a preparation method of an iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball and application of the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball in a sodium ion battery accessory material. Background Sodium ion batteries are considered as candidates for a new generation of large-scale energy storage devices because of the advantages of abundant sodium resources, low cost, high safety and the like. The electrochemical performance of sodium ion batteries depends largely on the choice of electrode materials. For the negative electrode side, na + has a large ionic radius and cannot be effectively intercalated into commercial lithium battery negative electrode materials such as graphite, so that development of a sodium storage negative electrode material with high specific capacity, high multiplying power and long cycle life is urgently needed. Ternary metal phosphorus sulfide MPS x (m= Fe, mn, ni, co, etc.) becomes a potential novel negative electrode material due to its unique two-dimensional layered structure, fully exposed surfaces, adjustable morphology and expandable channels. At the same time, the electronic tunability of MPS x is able to induce its chemical diversity and intrinsic activity, thus achieving faster charge conduction properties than single phosphorus/sulfide or binary layered materials. Among the numerous MPS x materials, iron trisulfide (FePS 3) has a higher theoretical specific capacity (1318 mAh g -1) and a large interlayer spacingIs considered to be an ideal electrode material for achieving rapid Na + deintercalation. However, fePS 3 has higher theoretical specific capacity as a negative electrode of a sodium ion battery, but the problems of serious volume expansion, low first-circle coulomb efficiency, rapid capacity decay and the like still exist in practical application. In addition, in the traditional preparation method, the synthesis condition of FePS 3 is usually harsh, and high-temperature high-pressure and long-time reaction conditions are needed, so that not only are the energy consumption and the cost of material preparation increased, but also certain potential safety hazards exist, and the practical application of FePS 3 is limited. The prior invention patent CN111261857A discloses a FePS 3/NC composite anode material for a sodium ion battery, the prepared composite material is in a lamellar structure, carbon is uniformly attached to the surface, the volume expansion of the anode material in the sodium storage reaction process is effectively buffered, and the rapid transfer of electrons/ions is promoted. However, the preparation process of the composite anode material is complex, the yield is low, and the composite anode material is not suitable for mass production. Another invention patent CN111403730a discloses a FePS 3 @mxene nanocomposite anode material for sodium ion battery and a preparation method thereof, the material has a unique 2D/2D hybrid structure, can promote rapid transfer of electrons/ions, and inhibits volume expansion of the electrode. But the cycle life is short and the capacity of the electrode material begins to decay significantly after 50 cycles. In addition, the preparation process is quite complicated, and involves steps of etching, two solid-liquid separations, preparation of FePS 3 crystals and the like. Therefore, it is necessary to further design and optimize FePS 3 preparation process to improve the specific sodium storage capacity, multiplying power and cycle performance. Disclosure of Invention In order to solve the technical problems, the invention provides a preparation method of an iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball and application of the iron trisulfide and phosphorus oxide/nitrogen doped carbon composite flower ball in a sodium ion battery accessory material. According to the invention, prussian blue with a nano-cube structure is used as a functional precursor, and cubic Prussian blue is converted into a flower-spherical ferric trisulfide phosphate/nitrogen doped carbon composite material in situ through one-step gas-phase sulfur-phosphorus treatment, and the material can show excellent electrochemical performance when being used as a negative electrode of a sodium ion battery. The technical scheme of the invention is as follows: Firstly, the invention provides a preparation method of iron trisulfide and phosphorus compound carbon-doped flower ball, which comprises the following steps of (1) adding an iron source and polyvinylpyrrolidone into dilute hydrochloric acid, and uniformly stirring