Germanium and barium activated lithium iron phosphate anode material

Abstract

The invention provides a germanium and barium activated lithium iron phosphate anode material. The chemical formula of the material can be represented as LiGexBay FePO4, wherein x is equal to 0.0000-0.00005 and y is equal to 0.0003-0.003; the mol ratio of Li, Ge, Ba, Fe and P is as follows: Li to Ge to Ba to Fe to P is equal to 1 mol to 0.00002-0.00005 mol to 0.0003-0.003 mol to 1 mol to 1 mol; as less substituted germanium and barium is doped, the appearance and the grain diameter of a product are easy to control and a stable lithium iron phosphate compound is obtained; the crystal lattice of the lithium iron phosphate compound is activated, the lithium ion diffusion coefficient is improved and the initial discharge capacity reaches 160.52 mAh / g; the potential of a charge-discharge platform corresponding to a lithium electrode is about 3.5 V, the initial discharge capacity exceeds 168 mAh / g and the capacity is attenuated by about 1.2% after 100 times of charge-discharge cycles; and compared with the undoped LiFePO4 comparing embodiment, the specific capacity and the cycling stability of the anode material are greatly improved.

Description

technical field [0001] The germanium and barium activated lithium iron phosphate positive electrode material of the invention belongs to a lithium battery positive electrode material, in particular to a lithium iron phosphate battery positive electrode material. 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, and the rate performance is extremely poor. Researchers at home and abroad have used methods such as c...

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