Preparation method of copper-barium-activated lithium iron phosphate anode material

Abstract

The invention relates to a preparation method of a copper-barium-activated lithium iron phosphate anode material. The preparation method comprises the following steps of: mixing raw materials, such as a lithium source, an iron source, a phosphate radical source, a copper source and a barium source according to a mol ratio of 1 of Li to Cu to Ba to Fe to P of 1: (0.00002-0.00005):0.0003:1:1; performing high-speed ball milling at a rotating speed of 200r / min for 20 hours in an absolute ethyl alcohol medium; drying at 105-120 DEG C to obtain a precursor; and placing the precursor obtained by drying into a high-temperature furnace, and calcining the precursor at 500-750 DEG C for 24 hours in an ordinary pure nitrogen atmosphere to obtain the copper-barium-activated lithium iron phosphate anode material. Because a small amount of substituting copper and barium are doped, the shape and the particle size of the copper-barium-activated lithium iron phosphate anode material can be conveniently controlled to obtain a stable lithium iron phosphate compound, the crystal lattice of the lithium iron phosphate compound is activated, the diffusion coefficient of lithium ions is increased, and the first-time discharge capacity of the obtained material reaches 160.52mAh / g; the electric potential of a charging and discharging platform of the copper-barium-activated lithium iron phosphate anode material relative to a lithium electrode is about 3.5V, the initial discharge capacity is more than 168mAh / g, and after 100 times of charging and discharging circulation, the capacity is approximately attenuated by about 1.2 percent; and compared with a contrast embodiment without doping of LiFePO4, the copper-barium-activated lithium iron phosphate anode material has the advantage that: the specific capacity and the cycle stability are greatly improved.

Description

technical field [0001] The method for preparing a positive electrode material of copper 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, ...

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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