Preparation method of sodium vanadium fluorophosphate positive electrode material

Abstract

The invention provides a preparation method of a sodium vanadium fluorophosphate positive electrode material. The preparation method comprises the following steps: mixing a vanadium source, a phosphorus source, a sodium source, a fluorine source and an organic reducing agent to prepare a solution, carrying out spray pyrolysis to obtain Na3V2(PO4)2F3 microspheres, and carrying out mechanical ball milling on the Na3V2(PO4)2F3 microspheres and a carbon material to obtain a well-crystallized Na3V2(PO4)2F3/C material. Compared with the traditional ball milling method, the spray pyrolysis-mechanicalball milling method adopted by the invention has the advantages of high material synthesis speed, low energy consumption, high yield, simple process, easiness in operation and the like, and avoids the long-time sintering process of the raw materials at high temperature. The obtained Na3V2(PO4)2F3 microspheres and the final Na3V2(PO4)2F3/C material have spherical morphology and are relatively small in particle size. The prepared Na3V2(PO4)2F3/C material passes an electrochemical performance test, has relatively good specific discharge capacity, and has a relatively good application prospect ina sodium-ion battery positive electrode material.

Description

technical field [0001] The invention relates to the field of anode materials for sodium ion batteries, in particular to a preparation method for sodium vanadium fluorophosphate cathode materials. Background technique [0002] With the rapid development of the 3C field, new energy vehicles and new energy storage, lithium-ion batteries have been widely used. People are no longer satisfied with the energy density of existing devices, and the demand for lithium-ion batteries is also increasing. Since 2016, the price of lithium carbonate has continued to rise. It is worth noting that the abundance of lithium in the earth is about 0.0065%. Such a low amount of resources cannot bear the huge consumption of lithium resources. The development of lithium-ion batteries will undoubtedly be constrained by prices. Sodium-ion batteries are considered to be the best candidate power sources because sodium and lithium elements are in the same main group, adjacent in position, and have simil...

AI Technical Summary

Problems solved by technology

According to current reports, Na 3 V 2( PO 4 ) 2 f 3 The synthesis methods mainly include ball milling method, high-temperature solid-phase method, and hydrothermal method. These methods all have high temperature (600°C-700°C) and long-term (4h-12h) sintering process, so the preparation time is long and the energy consumption is high.

[0004] Chinese patent CN103594716A discloses a method for preparing sodium vanadium fluorophosphate positive electrode material through sol-gel activation-assisted two-step high-temperature solid-phase method. The material prepared by this method has the characteristics of good stability and uniform particle size, but the reaction process is long. high production cost

[0005] Chinese patent CN108682855A discloses a method for the controllable preparation of sodium vanadium fluorophosphate positive electrode material by hydrothermal method. The hydrothermal time is as long as 6 to 12 hours, the reaction process is very long, and the price of raw materials is high, which is not conducive to large-scale production.

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