Synthesis method of lithium iron phosphate lithium ion battery cathode material

Abstract

The invention discloses a synthesizing method of anode material lithium iron phosphate of a lithium ion battery, and mainly aims to ensure conductivity and improve processing performance of an electrode material. The method comprises the following steps of: synthesizing a precursor, sintering to obtain the composite material of LiFePO4 and C, performing a low-temperature oxidation reaction, and performing a high-temperature reduction reaction to obtain the anode material lithium iron phosphate of the lithium ion battery. Compared with the prior art, through high-temperature treatment and the reduction reaction, the carbon in the lithium iron phosphate material is consumed, so that the content of the carbon in the lithium iron phosphate material is reduced, the uniformity of a carbon coating layer in the lithium iron phosphate material is improved, the conductivity is ensured, the carbon content is reduced, the utilization ratio of the carbon in the lithium iron phosphate material is increased, the specific surface area of the material is decreased, and the processing performance of the material is improved.

Description

technical field [0001] The invention relates to a method for synthesizing a positive electrode material of a lithium ion battery, in particular to a method for synthesizing lithium iron phosphate. Background technique [0002] Lithium-ion battery lithium iron phosphate cathode material has been widely used in various power lithium-ion batteries. Since lithium iron phosphate has the defect of low electronic conductivity and ionic conductivity, in order to overcome this defect, the current general method is to decompose the amorphous carbon layer material coated on the surface of lithium iron phosphate material through organic matter. Coating carbon on the surface of lithium iron phosphate materials has three main effects on lithium iron phosphate materials or in its synthesis process: 1. Reduction of ferric ions, ferric iron or other forms of ferric iron in raw materials; 2. Preventing The particles grow up to ensure high ion conductivity and increase the lithium ion transmi...

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Problems solved by technology

For the same type of material, although the increase of carbon content or specific surface area can improve the electronic conductivity of the material and reduce the internal resistance of the battery, but at the same time, the surface energy is large, and the tendency of particles to aggregate during the electrode slurrying process is strong. Overcoming the surface energy The force required for dispersion increases correspondingly, the material is easy to agglomerate and difficult to disperse, and the uniformity of the slurry is relatively poor

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