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CN-119695105-B - Preparation method and application of nickel disulfide/copper sulfide/carbon composite hollow sphere

CN119695105BCN 119695105 BCN119695105 BCN 119695105BCN-119695105-B

Abstract

The invention relates to the field of batteries, and discloses a preparation method and application of nickel disulfide/copper sulfide/carbon composite hollow spheres. The invention uses hollow sphere Ni-MOF as a precursor, and combines the following ion exchange, PDA coating, glucose coating, carbonization and vulcanization to prepare the nickel disulfide/copper sulfide/carbon composite hollow sphere. The material inherits the Ni-MOF porous hollow structure, can provide a high-speed effective transmission channel for ion diffusion in the electrode material, simultaneously relieves the volume change effect and prolongs the cycle life of the sodium ion battery. In addition, a proper amount of copper ions are controllably introduced through ion exchange to form a nickel-copper bimetallic sulfide heterostructure, so that ion diffusion kinetics can be accelerated, an ion diffusion barrier can be reduced, and structural stability can be enhanced. Finally, the nitrogen-doped carbon derived from carbonization of polydopamine in the middle layer improves the conductivity of the composite material, increases the active site for sodium storage, and the carbon layer derived from carbonization of glucose in the outermost layer further enhances the structural stability of the composite material.

Inventors

  • YANG YEFENG
  • WANG SHUAI
  • SUN JUNJIE
  • HUANG ZHENNI
  • SONG SHANSHAN
  • YAO ZHUJUN

Assignees

  • 浙江理工大学

Dates

Publication Date
20260505
Application Date
20241216

Claims (8)

  1. 1. The preparation method of the nickel disulfide/copper sulfide/carbon composite hollow sphere is characterized by comprising the following steps of: (1) Mixing and dissolving nickel salt and organic ligand trimesic acid and a surfactant in a solvent, and performing solvothermal reaction to obtain Ni-MOF hollow spheres; (2) Mixing and dispersing the Ni-MOF hollow spheres and copper salt in a solvent, stirring, reacting and centrifuging to obtain CuNi-MOF, wherein the mass ratio of the Ni-MOF hollow spheres to the copper salt is 1 (2-7); (3) Dispersing CuNi-MOF in a buffer solution, adding dopamine hydrochloride (PDA), stirring for reaction, and centrifuging to obtain CuNi-MOF/PDA, wherein the mass ratio of the CuNi-MOF to the dopamine hydrochloride is 1 (5-10); (4) Dispersing CuNi-MOF/PDA in a solvent, adding glucose, stirring, and performing solvothermal reaction to obtain CuNi-MOF/PDA/C 6 H 12 O 6 , wherein the mass ratio of the CuNi-MOF/PDA to the glucose is 1 (10-30); (5) Calcining CuNi-MOF/PDA/C 6 H 12 O 6 in nitrogen or argon atmosphere, and heating to 400-600 ℃ at a heating rate of 2-5 ℃ per minute for calcining for 1-3 hours to obtain a CuNi/NC/C hollow sphere; (6) And (3) carrying out gas-phase vulcanization on the CuNi/NC/C hollow sphere to obtain the nickel disulfide/copper sulfide/carbon composite hollow sphere, wherein the gas-phase vulcanization condition is that the mass ratio of the CuNi/NC/C hollow sphere to the sulfur powder is 1 (3-6), the vulcanization temperature is 300-500 ℃, and the heating rate is 2-5 ℃.
  2. 2. The process according to claim 1, wherein in step (1), The mass ratio of the nickel salt to the organic ligand to the surfactant is 1 (0.3-0.5) (2-6); the surfactant is polyvinylpyrrolidone; The nickel salt is nickel nitrate hexahydrate, nickel chloride or nickel sulfate heptahydrate.
  3. 3. The preparation method of claim 1, wherein in the step (1), the solvent is a mixed solution of water, anhydrous ethanol and N, N-dimethylformamide in a volume ratio of (0.8-1.2).
  4. 4. The method according to claim 1, wherein in the step (1), the solvothermal reaction is carried out at 130 to 170 ℃ for 10 to 16 hours.
  5. 5. The process according to claim 1, wherein in step (2), The copper salt is copper sulfate pentahydrate, copper nitrate trihydrate or copper chloride; the solvent is methanol, absolute ethyl alcohol or N, N-dimethylformamide.
  6. 6. The method of claim 1, wherein in step (4), the solvent is ethylene glycol or N, N-dimethylformamide.
  7. 7. The method according to claim 1, wherein in the step (4), the solvothermal reaction is carried out at 130 to 170 ℃ for 5 to 10 hours.
  8. 8. Use of the nickel disulfide/copper sulfide/carbon composite hollow sphere prepared by the preparation method according to any one of claims 1-7 as a negative electrode material of a sodium ion battery.

Description

Preparation method and application of nickel disulfide/copper sulfide/carbon composite hollow sphere Technical Field The invention belongs to the field of batteries, and particularly relates to a preparation method and application of a nickel disulfide/copper sulfide/carbon composite hollow sphere. 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 resource sources, 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. Nickel disulfide is a potential negative electrode material of a sodium ion battery due to the characteristics of high theoretical specific capacity (870 mAh g -1), relatively low voltage platform and the like. However, the problems of low electronic conductivity, easy agglomeration in the preparation process, serious volume change in the electrochemical process and the like of nickel disulfide prevent the further development and application of the nickel disulfide in sodium ion batteries. Aiming at the problems, researchers mainly adopt strategies for improvement of (1) material nanocrystallization design (such as quantum dots, nanowires, nanosheets and the like), (2) compounding with materials with good conductivity (such as graphene, carbon nanotubes and the like), and (3) constructing a bimetallic sulfide heterojunction. Among them, the construction of heterostructures is a strategy with outstanding advantages. The heterostructure formed by different materials not only integrates the energy storage advantages of two or more materials, but also forms rich defects at the heterogeneous interface, thereby being beneficial to increasing Na + storage sites. In addition, the built-in electric field spontaneously formed at the heterogeneous interface plays a positive role in enhancing the kinetics of sodium storage reaction. The advantage of different component materials can be exerted to the maximum extent through the heterostructure which is reasonably designed and prepared, but the preparation method of the heterostructure is often quite complex and difficult to control. The prior invention patent CN116588974A discloses a NiS 2/MoS2/C composite negative electrode material for a sodium ion battery, which is prepared by (1) mixing nickel salt with a complexing agent, preparing a carbon frame composite material by adopting a hard template method, (2) mixing the carbon frame composite material, ammonium heptamolybdate and thiourea, preparing a carbon-loaded MoS x nano-sheet composite material through hydrothermal reaction, and (3) roasting the carbon-loaded MoS x nano-sheet composite material under the action of a vulcanizing agent to prepare the carbon-loaded MoS 2 nano-sheet and NiS 2 nano-crystal composite material. The prepared composite material is in a lamellar structure, so that 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 method is relatively complex, the proportion of two metal ions cannot be accurately controlled, and the molybdenum in the raw material is used as rare metal, so that the cost of the raw material is high. Disclosure of Invention Aiming at the defects and problems existing in the prior art, the invention provides a preparation method and application of a nickel disulfide/copper sulfide/carbon composite hollow sphere. The invention prepares the nickel disulfide/copper sulfide/carbon composite hollow sphere by taking hollow spherical Ni-MOF synthesized by a simple solvothermal method as a precursor and combining ion exchange, dopamine hydrochloride (PDA) and glucose double-layer cladding, carbonization and vulcanization. The prepared nickel disulfide/copper sulfide/carbon composite hollow sphere composite material inherits a porous hollow structure of Ni-MOF, can provide a high-speed effective transmission channel for Na + ion diffusion in an electrode material, simultaneously relieves volume expansion and contraction, and prolongs the cycle life of a sodium ion battery. In addition, a proper amount of copper ions are controllably introduced through ion exchange to form a nickel-copper bimetallic sulfide heterostructure, so that ion diffusion kinetics can be accelerated, an ion diffusion barrier is reduced, structural stability is enhanced, finally, the nitrogen doped carbon derived from carbonization of polydopamine in the middle layer improves conductivity of the composite material, s