Vanadium and barium activated lithium iron phosphate anode material

Abstract

The invention discloses a vanadium and barium activated lithium iron phosphate anode material. The chemical general formula of the vanadium and barium activated lithium iron phosphate anode material can be formulated to be LiVxBayFePO4, wherein x is equal to 0.00002-0.00005; y is equal to 0.0003-0.003; and the mol ratio of Li to V to Ba to Fe to P is 1: 0.00002-0.00005: 0.0003-0.003: 1: 1. As a little impurity is doped to replace vanadium and barium, the appearance and the particle size of a product are controlled beneficially; stable lithium iron phosphate compound is obtained; crystal lattices of the lithium iron phosphate anode material are activated; the diffusion coefficient of lithium ions is improved; the first discharge capacity of the lithium iron phosphate anode material reaches 160.52 mAh/g; the electric potential of a charging/discharging platform of the lithium iron phosphate anode material relative to a lithium electrode is about 3.5 V; the initial discharge capacity exceeds 168 mAh/g; the capacity is approximately attenuated for about 1.2% after 100 times of charging/discharging circulation; and compared with an undoped LiFePO4 contrast embodiment, the specific capacity and the circulation stability are improved more greatly.

Description

technical field [0001] The vanadium 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