Preparation method of lithium manganese phosphate and carbon nanotube nanocomposite

Abstract

The invention relates to a preparation method for a manganese-lithium phosphate and carbon nano tube nanocomposite. The method comprises the following processes: dripping phosphoric acid into a lithium hydroxide solution to prepare lithium phosphate, then adding manganese salt and ferric salt into a lithium phosphate dispersing solution and stirring uniformly to obtain a precursor solution, conducting a heat seal reaction to obtain manganese-lithium phosphate or iron-doped manganese-lithium phosphate, adding the manganese-lithium phosphate or iron-doped manganese-lithium phosphate and cobalt nitrate into deionized water, mixing, then dripping a sodium hydroxide solution, and washing, filtering in a suction manner, grinding, calcinating, reducing and growing a precipitate to obtain the manganese-lithium phosphate and carbon nano tube nanocomposite or an iron-doped manganese-lithium phosphate and carbon nano tube nanocomposite. According to the nanocomposite prepared with the method, a carbon nano tube grows uniformly on the manganese-lithium phosphate, the degree of graphitization is high, the process is simple, the defect of low electronic conductivity of manganese-lithium phosphate or iron-doped manganese-lithium phosphate is overcome, the charge and discharge properties of the nanocomposite are improved, and the application prospect is broad.

Description

technical field [0001] The invention relates to a preparation method of a lithium manganese phosphate and carbon nanotube nanocomposite material, belonging to the technical field of cathode materials for lithium ion batteries. Background technique [0002] With the rapid development of modern integrated circuits, electronic instruments continue to develop in the direction of small and light weight, which puts forward higher requirements for small chemical power supplies: higher capacity, smaller size, lighter weight and longer use Lifespan etc. Traditional secondary batteries, such as lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, etc. are difficult to meet these requirements. Lithium-ion secondary batteries are favored by people because of their outstanding advantages such as high working voltage, high specific energy, large capacity, small self-discharge, good cycle performance, long service life, light weight, small size, no pollution, an...

AI Technical Summary

Problems solved by technology

[0005] Patent 200410051045.8 discloses a method of directly adding carbon nanotubes to lithium iron phosphate cathode material to improve electrical conductivity, but carbon nanotubes have the disadvantages of serious agglomeration and extremely difficult dispersion, and cannot be effectively and uniformly mixed with lithium iron phosphate

Patent 201110397625.2 discloses a method of using Fe, Co or Ni compounds as catalysts and doping elements to catalyze pyrolyzed hydrocarbon gas to prepare in-situ carbon nanotube composite lithium manganese phosphate materials. The catalytic activity is low, and the prepared carbon nanotubes have a low degree of graphitization and contain a large amount of amorphous carbon, which cannot effectively improve the conductivity of lithium manganese phosphate

Summarizing the relevant patents in recent years, it is found that a method for in-situ synthesis of carbon nanotubes with a high degree of graphitization on lithium manganese phosphate has not been reported in the art

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