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

A technology of lithium ferrous phosphate and cathode material, applied in battery electrodes, electrical components, circuits, etc., can solve the problems of difficult control of nanotube growth efficiency, uneven distribution of carbon nanotubes, unstable electrochemical performance, etc. The effect of increased voltage platform, simple preparation process and good cycle performance

Active Publication Date: 2013-01-02
贵州唯特高新能源科技有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the uneven distribution of carbon transported in the gas phase on the sample, the growth efficiency of nanotubes grown from carbon sources is difficult to control, and the grown nanotubes may not be in good contact with the lithium iron phosphate composite material, resulting in poor electrochemical performance of the prepared samples. Instability, and in the preparation of the sample, the carbon nanotubes will be unevenly distributed on the lithium iron phosphate, and there are shortcomings such as unstable batch performance of the prepared sample

Method used

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

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] 1) Preparation of carbon compounds

[0031] Mix citric acid and ethylene glycol in a molar ratio of 1:4, and stir at 45°C for 2 hours; place under the conditions of pressure of 10Pa and temperature of 125°C and stir for 5h to carry out the polymerization reaction; vacuum under the conditions of temperature of 175°C and pressure of 10Pa dry. The ethylene glycol that did not participate in the polymerization reaction was removed to obtain a brown mucus. The brown mucilage was placed in a tube furnace, heated to 300 °C isolated from air, and sintered at 300 °C for 3 hours; cooled to room temperature, and pulverized into a powdered precursor with a particle size of 20 meshes; the powdered precursor was placed in Al 2 O 3 In a porcelain boat, the carbon compounds were prepared by sintering at 400 °C for 8 h in an air atmosphere, and then naturally cooled to room temperature.

[0032] 2) Preparation of reduced carbon compounds

[0033] According to Na 2 SO 3 Weigh Na in...

Embodiment 2

[0037] 1) Preparation of carbon compounds

[0038] The citric acid and ethylene glycol were mixed according to the molar ratio of 1:4, stirred at 70 °C for 2 hours, placed under the conditions of a pressure of 10132 Pa and a temperature of 175 °C and stirred for 5 hours to carry out the polymerization reaction. Under the conditions of temperature 175 ℃ and pressure 1013Pa, vacuum drying to remove ethylene glycol that did not participate in the polymerization reaction to obtain brown mucilage; heat the brown mucilage to 300 ℃ isolated from air, and sinter at 300 ℃ for 3 hours; cool to room temperature, and pulverize into particle size 200 mesh powder precursor; place the powder precursor in Al 2 O 3 In a porcelain boat, the carbon compounds were prepared by sintering at 400 °C for 8 hours in an air atmosphere, and then cooling naturally.

[0039] 2) Preparation of reduced carbon compounds

[0040] Weigh sodium borohydride according to the weight ratio of sodium borohydride t...

Embodiment 3

[0044] 1) Preparation of carbon compounds

[0045] Mix citric acid and ethylene glycol in a molar ratio of 1:4, stir at 60 °C for 2 h, place at 1013Pa and stir at 165 °C for 5 h to carry out the polymerization reaction; vacuum dry at 175 °C under a pressure of 1013Pa, remove those that do not participate in the polymerization reaction. Ethylene glycol, to get brown slime. The brown mucilage was heated to 300 °C in isolation from the air, sintered at 300 °C for 3 h, cooled to room temperature, and pulverized into a powdery precursor with a particle size of 100 mesh; the powdered precursor was placed in Al 2 O 3 In a porcelain boat, the carbon compounds were prepared by sintering at 400 °C for 8 h in an air atmosphere, and then cooling to room temperature naturally.

[0046] 2) Preparation of reduced carbon compounds

[0047] Triethylsilane was weighed at 1:100 in weight ratio of triethylsilane to carbon compound. The triethylsilane solution was prepared by dissolving trieth...

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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...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/58
CPCY02E60/12Y02E60/10
Inventor 童庆松黄娟韩铭姜祥祥周慧蔡斌王浪
Owner 贵州唯特高新能源科技有限公司
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