Preparation method of coated lithium iron phosphate positive electrode material

Abstract

The invention relates to a preparation method of a coated lithium iron phosphate positive electrode material. According to the method provided by the invention, the lithium iron phosphate positive electrode material is prepared by adopting a plasma high-temperature melting technology; a complete coating material coats the lithium iron phosphate positive electrode material by adopting a liquid-phase coating method, so that the conductivity is improved. The method provided by the invention is simple and easy to operate, the cost is low, and time consumption is short; the obtained lithium iron phosphate material has a regular shape and is in a highly spherical shape; components of the lithium iron phosphate material are uniform and are not agglomerated, and the lithium iron phosphate material has stable electrochemical performance, relatively good conductivity and circulating performance, relatively high specific capacity and relatively long service life.

Description

technical field [0001] The invention relates to the field of battery materials, in particular to a method for preparing a coated lithium iron phosphate cathode material. Background technique [0002] Lithium-ion batteries are a new generation of green high-energy batteries. They have many advantages such as high voltage, high energy density, good cycle performance, small self-discharge, no memory effect, and wide operating temperature range. They are widely used in phones, laptops, and power tools. It also has good application prospects in electric vehicles, and is considered to be an important high-energy technology product in the 21st century. [0003] The current commercial lithium-ion cathode materials are mainly lithium iron phosphate (LiFePO4), ternary materials (nickel-cobalt-manganese ternary material NCM, nickel-cobalt-aluminum ternary material NCA) and lithium manganese oxide (LiMn2O4), among which The cycle life of lithium manganate battery is short and the cycle...

AI Technical Summary

Problems solved by technology

However, when the conventional high-temperature solid-phase synthesis method is used to prepare lithium iron phosphate, a large amount of inert protective gas is required, and the cost of the inert gas is relatively high.

[0005] In addition, the ionic and electronic conductivity of lithium iron phosphate is poor. In the prior art, technologies such as carbon coating, nanonization of material particles, and metal ion doping are generally used to improve the rate performance of the battery and improve its cycle stability. sex

However, nanonization makes the processing performance of the material worse, and the doping modification process is more complicated, which needs to be improved and developed.