Preparation method and application of a heteroelement-doped carbon nanotube-encapsulated metal sulfide composite negative electrode material

Abstract

The invention discloses a preparation method and application of a heteroelement-doped carbon nanotube-encapsulated metal sulfide composite negative electrode material. Disperse transition metal salts, fructose, cyanoamine, etc. in a solvent and mix them uniformly, then undergo rotary evaporation treatment, fully dry the obtained powder, and sinter at high temperature in an inert atmosphere, and heat-treated powder. Thioacetamide hydrothermal vulcanization treatment can obtain heteroelement-doped carbon nanotube-encapsulated metal sulfide materials. The composite electrode prepared by encapsulating metal sulfide materials with heteroelement-doped carbon nanotubes, according to the characteristics of the negative electrode materials of sodium ion batteries in the charge-discharge cycle, encapsulates and coats a uniform carbon layer on the outside of the active material, and the carbon nanotubes The one-dimensional structure is conducive to improving electron conduction, thereby effectively improving and enhancing the electrochemical performance of electrode materials. The preparation and operation process of the invention is simple, the yield is high, the charge and discharge performance of the material is excellent, and the industrial production is convenient.

Description

technical field

[0001] The invention relates to the technical field of negative electrode materials for sodium ion batteries, in particular to a preparation method and application of heteroelement-doped carbon nanotube-encapsulated metal sulfide composite negative electrode materials. Background technique

[0002] The working principle of sodium-ion batteries is similar to that of lithium-ion batteries, using the intercalation process of sodium ions between the positive and negative electrodes to achieve charge and discharge. Compared with lithium-ion batteries, sodium-ion batteries have the following advantages: (1) Na-salt raw materials are rich in reserves and low in price. Compared with lithium-ion battery ternary cathode materials, the cost of raw materials is reduced by half by using iron-manganese-nickel-based cathode materials; 2) Due to the characteristics of sodium salt, it is allowed to use low-concentration electrolyte (with the same concentration electrolyte, th...

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