Lithium iron phosphate anode material with activating aluminum and barium

Abstract

The invention provides a lithium iron phosphate anode material with activating aluminum and barium, wherein the chemical formula can be expressed as follows: LiAlxBayFePO4, wherein X=0.002-0.005, and y=0.0003-0.003; the mol ratio of Li, Al, Ba, Fe and P is as follows: 1 mol of Li: 0.002-0.005 mol of Al: 0.0003-0.003 mol of Ba: 1 mol of Fe: 1 mol of P; after a small quantity of substituted aluminum and barium are doped, the shape and the grain diameter of a product can be preferably controlled, a stable lithium iron phosphate chemical compound can be obtained, the crystal lattice can be activated, the diffusion coefficient of lithium ions can be improved, and the first discharge capacity can reach 155.52mAh / g; the electric potential of a charge / discharge platform is about 3.5V relative to a lithium electrode, the initial discharge capacity exceeds 164mAh / g, and the capacity is attenuated by about 3.0% after 100 times of charge / discharge circulation; compared with the embodiment which is not doped with LiFePO4, the specific capacity and the cyclical stability can be greatly improved; and as the price of Ba is lower than the price of Li by more than 100 times, the production cost can be reduced by more than 10 times.

Description

technical field [0001] The aluminum 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 co...

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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