Method for preparing lithium iron phosphate

Abstract

The invention relates to a method for preparing lithium iron phosphate; wherein, the method includes mixing the water solutions of a ferric salt, a phosphoric acid and / or a phosphate, and an ammonia and / or an organic amine with the carbon atom number of 1 to 4 to acquire a mixture; drying the spray of the mixture to acquire a solid powder body; roasting the solid powder body with a temperature of 300- 900 DEG C and a time of 2- 24 hours to acquire an iron phosphate powder body; mixing the acquired iron phosphate powder body with a lithium salt and a carbon source uniformly and sintering thereof under an inert gas and / or a reducing gas. The first discharging capacity of a battery made by adopting the lithium iron phosphate prepared by the invention is remarkably higher than that of a battery made by the lithium iron phosphate prepared by the prior art.

Description

technical field [0001] The invention relates to a preparation method of lithium iron phosphate. Background technique [0002] As a chemical power source with high specific capacity, lithium-ion batteries have been widely used in mobile communications, notebook computers, video cameras, cameras, portable instruments and other fields. . LiFePO 4 It is a research hotspot of positive electrode active materials for lithium-ion batteries. Preliminary studies have shown that lithium iron phosphate (LiFePO 4 ) concentrated LiCoO 2 , LiNiO 2 , LiMnO 4 The respective advantages of such materials: no precious metals, cheap raw materials, extremely rich resources; moderate working voltage (3.4V); good platform characteristics, stable voltage, large theoretical capacity (170mAh / g); stable structure, good safety performance ( O and P are firmly combined with strong covalent bonds, which makes the material difficult to decompose by oxygen evolution); high temperature performance and...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to overcome the disadvantages of low initial discharge specific capacity of the battery made of lithium ferrous phosphate prepared in the prior art, complex preparation method of lithium ferrous phosphate, numerous procedures, and difficulty in controlling the shape and particle size, and to provide a battery made of lithium iron phosphate The first discharge specific capacity after the battery is high, the method is simple, the process is less, and the preparation method of lithium ferrous phosphate is easy to control the shape and particle size