Preparation method of carbon nanotube composite lithium iron phosphate anode material

Abstract

The invention belongs to the technical field of lithium ion battery anode materials, and particularly relates to a preparation method of a carbon nanotube composite lithium iron phosphate anode material. According to the method, a lithium source and an iron phosphate source are stirred and mixed in pure water according to an equimolar ratio, an organic carbon source, a carbon nanotube and a dispersing agent are added to carry out stirring and mixing, and the mixture is grinded through a stirring ball mill and a sand mill in sequence to obtain precursor slurry; the precursor slurry undergoes spray drying granulation to obtain spherical precursor powder; and the precursor powder is placed in a sintering furnace with a protection atmosphere for sintering, and then cooled to room temperature and grinded to obtain a product. According to the method, the dispersing agent is added to ensure that the carbon nanotube is uniformly dispersed in the waterborne slurry; and by adoption of a grindingmanner, the long-chain carbon nanotube is broken into a short chain to carry out carbon cladding on primary particles of lithium iron phosphate. The carbon cladding combined by amorphous carbon formed by pyrolysis of the organic carbon source and the carbon nanotube generates a synergistic effect, so that the rate discharging and low-temperature performance of the products is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of lithium ion battery cathode materials, in particular to a preparation method of carbon nanotube composite lithium iron phosphate cathode materials. Background technique [0002] Energy, information, and materials are juxtaposed as the three major symbols of modern human civilization. Entering the 21st century, batteries, as the most convenient mobile energy source, will penetrate into every corner of society, and they will be used all the time and everywhere. On the one hand, as the energy source of mobile electronic terminal equipment such as mobile phones, notebook computers, and cameras, low-power batteries have made great progress. Especially after the advent of lithium-ion batteries representing the most advanced technology of contemporary chemical power sources in 1990, they quickly occupied the "3C" due to their advantages such as high voltage, small size, high energy density, good cycle performan...

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Problems solved by technology

Cathode material LiCoO 2 The first problem is that the structure is not stable enough, and it will decompose when it is overcharged or overheated, which may cause the battery to explode. LiCoO 2 Application in Power Batteries

However, lithium iron phosphate has the following obvious disadvantages: (1) the electrical conductivity of lithium iron phosphate itself is low, resulting in poor high-rate charge and discharge performance; (2) LiFePO4

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