Preparation method of cobalt/barium activated lithium iron phosphate anode material

Abstract

The invention relates to a preparation method of a cobalt / barium activated lithium iron phosphate anode material, which comprises the following steps: mixing a lithium source, an iron source, a phosphate radical source, a cobalt source and a barium source at a ratio of 1mol Li : (0.00002-0.00005) mol Co : 0.0003 mol Ba : 1mol Fe : 1 mol P, performing high-speed ball milling in an anhydrous alcohol medium at a rotation speed of 200 r / min for 20 h, drying at 105-120 DEG C to obtain a precursor, placing the precursor obtained via the drying into a high-temperature furnace, and performing high-temperature calcination in a nitrogen atmosphere at 500-750 DEG C for 24 h to obtain the cobalt / barium activated lithium iron phosphate anode material. The doping of a small amount of cobalt / barium is helpful for controlling the morphological form and particle size of product and obtaining stable lithium iron phosphate compound, the crystal lattice of the cobalt / barium activated lithium ironphosphate anode material is activated so as to improve the lithium ion diffusion coefficient, and the initial discharge capacity of the obtained material is up to 160.52 mAh / g; the lithium electrode potential of the charging / discharging platform for the method is about 3.5 V, the initial discharging capacity is over 168 mAh / g, and the capacity after 100 cycles of charging / discharging is attenuated by about 1.2%; and comparing with the non-doped LiFePO4 comparison example, the specific capacity and cycle stability of the obtained material are greatly improved.

Description

technical field [0001] The invention relates to a method for preparing a positive electrode material activated by cobalt and barium iron phosphate, which belongs to a method for preparing a positive electrode material for 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, and ...

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