Carbon shell coated NiS classification microsphere and preparation method and application thereof

Abstract

The invention provides a carbon shell coated NiS classification microsphere and a preparation method and application thereof. A diameter of the carbon shell coated NiS classification microsphere is 3-4 micrometers. The NiS classification microsphere comprises a NiS microsphere core and a carbon shell coating the outer layer of the NiS microsphere. A clearance exists between the inner surface of the carbon shell and the outer surface of the NiS microsphere. The diameter of the NiS microsphere is 2-3 micrometers. According to the carbon shell coated NiS classification microsphere, the preparation method and the application, a carbon shell coated NiS classification microsphere electrode material is prepared through adoption of a solvothermal reaction-coating-calcining-etching four-step method. According to the carbon shell coated NiS classification microsphere, the preparation method and the application, on the basis that expansion coefficients of different dielectric materials are different, materials with different strain capacities are combined; when the carbon shell coated NiS classification microsphere is used as a sodium-ion battery anode material, the relatively high reversible capacity and excellent cycling stability are shown; the carbon shell coated NiS classification microsphere is a potential application material of a high-capacity and long-service-life sodium-ion battery; the cost of raw materials is low; a synthesis technology is simple; a condition is mild; a green chemical demand satisfied; and industrial application and popularization are facilitated.

Description

Technical field [0001] The invention belongs to the technical field of nanomaterials and electrochemistry, and specifically relates to a carbon shell-coated NiS hierarchical microsphere and a preparation method and application thereof. Background technique [0002] In recent years, with the development of industry and the extensive use of fossil fuels, environmental pollution has become more and more serious. Finding new green and clean energy has become an urgent problem to be solved, and energy storage systems have been the bottleneck in the development of clean energy. The preparation of high-efficiency and large-capacity energy storage systems is the key to energy transformation and green applications. Lithium-ion batteries are one of the most potential energy storage systems, but with the large-scale application of lithium-ion batteries, metal lithium resources are dropping sharply. According to statistics, at the current consumption rate, the existing lithium resources can...

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Problems solved by technology

However, this electrode material has a technical problem of irreversible phase transition due to its electrochemical conversion reaction, serious volume expansion, and difficulty in maintaining the structure, resulting in capacity fading and cycle life decline.

Therefore, how to improve the stability of transition metal sulfides in electrochemical reactions has become a research hotspot in recent years. The main strategy is to synthesize electrode materials with porous hierarchical structures and build core-shell structures. However, the general synthesis method has cumbersome synthesis steps. , low yield of synthetic products, etc., and the method of synthesizing carbon shell-coated NiS hierarchical microspheres through a simple four-step method of solvothermal reaction-coating-calcination-etching has not been reported so far.

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