The invention discloses a preparation method of
anode material
lithium iron (II)
phosphate for a
lithium ion cell. The preparation method mainly comprises the following two steps: (1) synthesis of precursor Li3Fe2(PO4)3, blending a
lithium source, an
iron source and a
phosphorus source according to that the
molar ratio of Li to Fe to P is 3:2:3, taking deionized water, absolute
ethanol or
acetone as a medium, ball-milling for 0.5-24 h,
drying the obtained
slurry, thermally treating for 3-24 hours at the temperature of 500-900 DEG C to obtain the precursor Li3Fe2(PO4)3; and (2) blending the obtained precursor Li3Fe2(PO4)3 and
iron powder according to the
molar ratio of 1:1, taking deionized water, absolute
ethanol or
acetone as the medium, ball-milling for 0.5-24 h,
drying the obtained
slurry, placing the dried
slurry into a high-temperature furnace, under the
atmosphere of inoxidizability, baking the dried slurry for 5-24 h at the temperature of 500-800 DEG C, and at last preparing the lithium iron (II)
phosphate material. By adopting the principle that the lithium iron (II)
phosphate material is synthesized by
oxidation reduction between zero-valent iron and
ferric iron source Li3Fe2(PO4)3 at high temperature, firstly, the pure phase Li3Fe2(PO4)3 intermediate is synthesized in advance, and then reacted with the zero-valent iron to synthesize the lithium iron (II) phosphate, so that the reaction process is easy to control. The synthesized product Li3Fe2(PO4)3 is high in
chemical purity, good in electrochemical performance and high in batch stability.