Preparation method and application of molybdenum phosphide/carbon fiber composite material

Abstract

The invention belongs to the technical field of transition metal phosphide composite materials. The invention provides a preparation method and application of a molybdenum phosphide / carbon fiber composite material. The preparation method comprises the steps of preparation of a spinning solution from a phosphorus source, a molybdenum source and a carbon source, electrostatic spinning, pre-oxidationand high-temperature carbonization, and the preparation method provided by the invention is simple to operate and can realize continuous production. Phosphomolybdic acid is dissolved in a phytic acidsolution to prepare the spinning solution, and the prepared spinning solution is stable and high in dispersity; the interaction force between transition metal and phosphide can be enhanced, and the phosphorus content of a product can be increased; the conductivity of the spinning solution is effectively improved, and the cycling stability and the rate capability of the molybdenum phosphide / carbonfiber composite material are improved. The molybdenum phosphide / carbon fiber composite material prepared by the invention is high in specific capacity, stable in circulation and excellent in rate capability when being applied to a negative electrode of a sodium-ion battery. The molybdenum phosphide / carbon fiber composite material still keeps the specific capacity of 100 mAh / g or above after 1000times of circulation under the current density of 1A / g, and thus is high in capacity retention rate.

Description

technical field [0001] The application belongs to the technical field of transition metal phosphide composite materials, and in particular relates to a preparation method and application of a molybdenum phosphide / carbon fiber composite material. Background technique [0002] The low cost and abundance of sodium sources and the similarity in chemical properties and electrochemical behavior between sodium and lithium make sodium-ion batteries considered to be an ideal replacement for lithium-ion batteries, but sodium-ion batteries suffer from poor cycle stability and low The capacity limits its large-scale energy storage applications. Anode is an important part of Na-ion batteries, and transition metal phosphides are promising anode materials for Na-ion batteries due to their low intercalation voltage, low polarization, and high capacity. Currently, transition metal phosphides have been synthesized by hydrothermal / solvothermal methods, high-energy ball milling, electrodeposit...

AI Technical Summary

Problems solved by technology

Among them, the most reported synthetic routes generally use organic phosphorus sources with high boiling points in the oil phase under an inert atmosphere. The disadvantages are that the reaction is flammable and corrosive at a relatively high decomposition temperature (300°C), and the long-chain organic solvents Difficult to remove

Another common synthetic route uses sodium hypophosphite to decompose at the intake end to generate phosphine, which is entrained by inert gas and reacts with metal precursors (metal oxides, hydroxides, metal organic framework compounds, etc.) to synthesize phosphides. The downside is that phosphine is extremely toxic and deadly

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