The invention discloses a method for preparing a
cathode material of a
sodium-
ion battery, namely
sodium vanadium fluorophosphates. The method comprises the following steps: using a
vanadium source, a
phosphorus source and a
carbon source as main synthetic raw materials; dissolving into deionized water according to the
molar ratio 1:1:1.2 of
vanadium:
phosphorus: carbon, heating in water bath, and continuously stirring to obtain light green pulp; after
vacuum drying,
grinding, then transferring into a
tube furnace, preburning in an
inert atmosphere at a certain temperature
rise rate, cooling and then taking out to obtain black VPO4 / C precursor
powder; mixing the VPO4 / C with NaF according to a stoichiometric ratio, ball-milling for 3 hours, sending into the
tube furnace, then
roasting in the
inert atmosphere at the certain temperature
rise rate, and cooling along with the furnace to obtain a positive active material NaVPO4F / C. According to the invention, cheap and easily-obtained pentavalent
vanadium oxide or trivalent
vanadium oxide is used as the main raw materials to prepare the
sodium vanadium fluorophosphates
cathode material through a
sol gel activated auxiliary two-step high-temperature
solid phase method, and the sodium vanadium fluorophosphates
cathode material has the advantages of good stability, uniform particle size and good electrochemical performance. Meanwhile, the method has the advantages of simple synthesis process, short period and low cost and is convenient for large-scale production.