Method for preparing vanadium and barium activated lithium iron phosphate anode material

Abstract

The invention relates to a method for preparing a vanadium and barium activated lithium iron phosphate anode material, which comprises the steps of mixing lithium source raw materials, iron source raw materials, phosphate radical source raw materials, vanadium source raw materials and barium source raw materials in the proportion of 1mol Li: 0.00002-0.00005mol V: 0.0003-0.003mol Ba: 1mol Fe: 1molP prior to ball milling in an absolute ethyl alcohol medium at a high revolution speed of 200r / min for 20h, obtaining a precursor after drying at the temperature ranging from 105 DEG C to 120 DEG C, and placing the obtained precursor by means of drying into a high-temperature furnace prior to being calcinated in an ordinary pure nitrogen atmosphere at the high temperature ranging from 500 DEG C to 750 DEG C for 24h, so that the vanadium and barium activated lithium iron phosphate anode material is obtained. By the aid of a small amount of substituted vanadium and barium which are doped, the shape and the grain size of a product can be controlled beneficially, and a stable lithium iron phosphate compound is obtained, so that crystal lattices of the stable lithium iron phosphate compound are activated, lithium-ion diffusion coefficient is increased, the first discharge capacity is as high as 160.52mAh / g, a charge-discharge platform is about 3.5V relative to a lithium electrode potential, the initial discharge capacity exceeds 168mAh / g, and the capacity is attenuated by about 1.2% after one hundred times of cycle. Compared with an embodiment of undoped LiFePO4, the vanadium and barium activated lithium iron phosphate anode material is higher in specific capacity and cyclical stability.

Description

technical field [0001] The method for preparing a positive electrode material of vanadium and barium activated lithium iron phosphate according to the invention belongs to a method for preparing a positive electrode material of a lithium battery, and in particular relates to a method for preparing a positive electrode material for a lithium iron phosphate battery. Background technique [0002] At present, the research status of lithium iron phosphate doping modification: lithium iron phosphate LiFePO4 is non-toxic, environmentally friendly, high in safety, rich in raw materials, high in specific capacity, stable in cycle performance, and low in price. The stable discharge platform with a theoretical capacity of 3.5V, the lithium iron phosphate material has high energy density, low price, and excellent safety, and is especially suitable for power batteries. But it has a higher resistivity. Due to lithium iron phosphate, the kinetics of LiFePO4 is not good at room temperature...

AI Technical Summary

Problems solved by technology

[0005] At present, there is a consensus that lithium iron phosphate has the advantages of good safety, no pollution, stable cycle performance, high specific capacity and low price, but it also has poor conductivity and the disadvantage of lower tap density