Method for preparing reduction carbon nano tube coated lithium iron phosphate cathode material

Abstract

The invention relates to a method for preparing a reduction carbon nano tube coated lithium iron phosphate cathode material, which is characterized by comprising the following preparation process of: heating citric acid and ethylene glycol to perform polymerization reaction, then carrying out air isolation presintering, cooling and grinding and sintering at a temperature of 400 DEG C in the air atmosphere to obtain a carbon compound; mixing the prepared carbon compound and a mixture of reducing agents to obtain a reduction carbon compound; carrying out mixing and ball milling on the reduction carbon compound, a lithium source compound, a ferrous source compound, a phosphoric acid source compound and a wet grinding medium and carrying out vacuum drying to obtain dry powder; and placing the dry powder in the inert atmosphere or the weakly reducing atmosphere, cooling, grinding and sieving the dry powder after sintering the dry powder at a temperature of 300 DEG C, placing the obtained powder in the inert atmosphere or the weakly reducing atmosphere again and obtaining the reduction carbon nano tube coated lithium iron phosphate cathode material by adopting a two-phase sintering method. The electrode material prepared by the method disclosed by the invention has uniform composition and has excellent discharge performance, particularly excellent discharge circulating performance under the condition of large current.

Description

technical field

[0001] The invention belongs to the technical field of lithium ion battery electrode materials, and relates to a preparation method of a lithium ferrous phosphate cathode material coated with reduced carbon nanotubes that can be used for lithium ion batteries, lithium batteries, polymer lithium ion batteries and supercapacitors. technical background

[0002] As a new-generation energy system, lithium-ion batteries are widely used in electric vehicles, satellites, aerospace and military fields. Numerous studies have shown that LiFeP0 4 It may become one of the most promising cathode materials for lithium-ion batteries. However, since LiFeP0 4 Due to the limitation of its own structure, the material has low electronic conductivity and poor ionic conductivity, resulting in poor high-rate charge-discharge performance, and cannot meet the requirements of practical applications without modification. In order to overcome the shortcomings of lithium iron phosphate...

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