Lithium vanadium phosphate cathode material as well as preparation method and application thereof

Abstract

The invention discloses a lithium vanadium phosphate cathode material which is mainly composed of lithium vanadium phosphate single crystal nanowires and lithium vanadium phosphate nanofibers in a crossed manner; wherein the lithium vanadium phosphate cathode material adopts a three-dimensional network structure. A preparation method for the lithium vanadium phosphate cathode material comprises the following steps: preparing a lithium vanadium phosphate sol spinning solution; then adding nickel nitrate or nickel acetate into the lithium vanadium phosphate sol spinning solution, and stirring until the nickel nitrate or nickel acetate is completely dissolved; finally, dropwise adding a polyacrylonitrile-N, N-dimethylformamide sol into the solution, and stirring to obtain a clear sol; conducting spinning on the clear sol to obtain a precursor fiber membrane; finally conducting pre-oxidation treatment on the precursor fiber membrane to be placed into a N2 atmosphere furnace to conduct heat treatment so as to obtain the lithium vanadium phosphate cathode material. The lithium vanadium phosphate single crystal nanowires and the lithium vanadium phosphate nanofibers are utilized and combined to form the three-dimensional network structure, so that the electron conductivity and the lithium ion diffusibility as well as the high-rate performance and the cyclic stability of the material are improved.

Description

technical field [0001] The invention belongs to the field of positive electrode materials for lithium ion batteries, and in particular relates to a lithium vanadium phosphate positive electrode material and a preparation method and application thereof. Background technique [0002] The lithium vanadium phosphate with monoclinic structure has attracted great attention in recent years because of its good electrical conductivity, high theoretical specific capacity, high operating voltage platform, and good safety and stability. Lithium vanadium phosphate has a three-dimensional skeleton structure, which creates a large three-dimensional transport channel for lithium ions. However due to its two [VO 6 ] The arrangement in which the octahedral structure is separated results in poor electron transport capability inside lithium vanadium phosphate, which limits its rate capability. Therefore, lithium vanadium phosphate needs to be modified to improve its rate performance. Current ...

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Problems solved by technology

Lithium vanadium phosphate nanofibers and nanorods have also attracted attention. At present, the research on lithium vanadium phosphate nanofibers and nanorods uses the traditional coating method to prepare electrodes. The coating method requires additional binders and conductive agents, which not only reduces the The content of the active material is reduced, and the combination between the active material and the current collector is affected by the volume change during the charging and discharging process, so the traditional method of preparing electrodes by coating film method greatly reduces the due to lithium vanadium phosphate nanofibers and nanorods. characteristic

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