Method for preparing cathode material of sodium-ion battery, namely sodium vanadium fluorophosphates

Abstract

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.

Description

technical field

[0001] The invention relates to a preparation method of sodium vanadium fluorophosphate, a positive electrode material of a sodium ion battery, that is, a method for preparing the positive electrode material of a sodium ion battery through a sol-gel-assisted two-stage high-temperature solid-phase method. The method belongs to the technical field of new energy material preparation. Background technique

[0002] At present, the research on high-performance lithium-ion batteries and their electrode materials is a hot spot in the fields of electrochemistry, material chemistry, physics, etc., and the properties of sodium ions and lithium ions, which are both the main group I of the periodic table of elements, have many similarities. At this point, it is entirely possible for sodium ions to construct a widely used secondary battery like lithium ions. Moreover, compared with lithium-ion batteries, sodium-ion batteries have lower raw material costs than lithium-ion ...

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