Nitrogen-doped porous carbon-loaded iron-based fluoride three-dimensional nanometer anode material for lithium ion battery and preparation method thereof

Abstract

The invention discloses a nitrogen-doped porous carbon-loaded iron-based fluoride three-dimensional nanometer anode material for a lithium ion battery and a preparation method thereof. The material includes nitrogen-doped porous carbon-coated ferric fluoride. The nitrogen-doped porous carbon coating is in situ performed on the surface of the ferric fluoride. The method comprises the following steps: utilizing an ionic liquid of fluoborate as a fluorine source, ferric salt soluble in alcohol as a ferric source and ethyl alcohol as a dispersing agent; dispersing the prepared nitrogen-doped porous carbon into an ethyl alcohol solution and fully dispersing; adding the ferric source, ultrasonically stirring, adding the fluorine source drop by drop and continuously stirring; after completely dropwise adding, controlling a certain reaction temperature and continuously stirring; centrifugally cleaning and drying; performing thermal treatment under low temperature, thereby acquiring a final material. The prepared nanometer composite material has a special morphological structure and an excellent electrochemical performance.

Description

technical field [0001] The invention belongs to the field of lithium ion batteries, and in particular relates to a lithium ion battery cathode material and a preparation method thereof. Background technique [0002] In the past few decades, lithium-ion batteries have been extensively and deeply studied by scientists due to their high energy density, high operating voltage and long cycle life, and are becoming more and more important in modern people's lives. The current commercial cathode material is LiCoO through intercalation reaction 2 and LiFePO 4 , but their capacity is limited, and it is difficult to meet the needs of rapidly developing electric vehicles and mobile devices. Iron-based fluorides are a promising class of cathode materials due to their high specific capacity and high operating voltage. Fluoride has been continuously studied since Arai et al. and Badway et al. used it as a cathode material for lithium batteries around 2000. Among them, FeF 3 With ult...

AI Technical Summary

Problems solved by technology

Due to the low carbon content (5-10%), and the carbon nanotubes are in the form of strips, this leads to the fact that carbon cannot be well coated on the surface of ferric fluoride

Serious contact between ferric fluoride and electrolyte, more side reactions

2. Since the carbon nanotubes are not doped with heteroatoms, the performance may be affected; 3. The material obtained by centrifugation has not been heat-treated at low temperature, and there will be residual ionic liquid on the surface, which will affect the electrochemical performance

[0012] 2. The material rate performance is poor, which is not conducive to the charge and discharge of large current

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