Boron and barium activated lithium iron phosphate anode material

Abstract

The invention discloses a boron and barium activated lithium iron phosphate anode material. The chemical general formula of the boron and barium activated lithium iron phosphate anode material can be expressed as LiBxBayFePO4, wherein x is equal to 0.00002-0.00005, y is equal to 0.0003-0.003, and the mol ratio of Li, B, Ba, Fe and P is 1:0.00002-0.00005:0.0003-0.003:1:1. Because a small quantity of replaced boron and barium is doped, the feature and the diameter diameter of a product are contributed to controlling to obtain stable lithium iron phosphate compound. The crystal lattice of the boron and barium activated lithium iron phosphate anode material is activated, a lithium ion diffusion coefficient is improved, and the first discharging volume of the anode materials reaches 160.52mAh / g; the voltage of the charging and discharging platform of the anode material is 3.5V relative to the potential of the lithium electrode, an initial discharging volume exceeds 168mAh / g, and volume is attenuated by about 1.2% after charging and discharging circulation for 100 times; and compared with an non-doped LiFePO4 contrast embodiment, the specific capacity and the cyclical stability are greatly improved.

Description

technical field [0001] The boron 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 coati...

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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