The invention relates to a method for preparing a
barium-activated
lithium iron phosphate cathode material. The method is characterized by comprising the steps of: mixing raw materials of a
lithium source, a ferrum source, a
phosphate source and a
barium source according to the proportion of Li:Ba:Fe:P of 1mol:(0.0003mol):1mol:1mol, performing high-speed ball-milling (at the rotating speed of 200r / min) on the mixed raw materials in an absolute ethyl
alcohol (AR) medium and
drying at 105-120 DEG C to obtain a precursor; and placing the dried precursor in a high-temperature furnace and calcining for 24h at a high temperature of 500-750DEG C in an ordinary pure
nitrogen atmosphere to obtain the
barium-activated
lithium iron phosphate cathode material. The chemical general formula of the material can be represented as Li Ba FePO4. As a bit of
substituent barium is doped, the appearance and the particle size of the product are favorably controlled, and a stable
lithium iron phosphate compound is obtained.
Barium ions replace lithium ions in an occupation manner, the
crystal lattice of the compound is activated, the
diffusion coefficient of the lithium ions is increased, and the first
discharge capacity of the
cathode material reaches 145.52mAh / g. The potential of a charge-
discharge platform of the
cathode material is about 3.5V compared with that of a
lithium electrode, the initial
discharge capacity exceeds 162mAh / g, and the capacity is attenuated by about 3.2% after 100 times of charge-discharge circles. Compared with the undoped LiFePO4 contrast embodiment, the
cathode material has greatly increased specific capacity and cyclical stability. As the price of barium is more than 100 times lower than the price of lithium, the production cost can be reduced by more than 10 times.