Sodium vanadium fluorophosphate, and preparation method and use thereof

Abstract

The invention provides a preparation method and a use of sodium vanadium fluorophosphate. The preparation method of the sodium vanadium fluorophosphate comprises the following steps: dissolving or dispersing the following raw materials: a sodium source compound, a vanadium source compound, a phosphorus source compound and a fluorine source compound, in an organic solvent to obtain a mixture; and 2, transferring the mixture obtained in step 1 to a reaction kettle, heating the reaction kettle to 50-140DEG C, reacting the mixture, cooling the obtained product, washing the cooled product, and drying the washed product to obtain sodium vanadium fluorophosphate powder. Compared with high-temperature and complex-flow traditional technologies, the preparation method has the following advantage: the sodium vanadium fluorophosphate with good crystallinity and good electrochemical performances can be synthesized at a low temperature of 50-140DEG C only through a solvothermal reaction and precipitate washing short technology.

Description

technical field [0001] The invention belongs to the technical field of electrode materials, in particular to a vanadium sodium fluorophosphate salt Na 3 (VO x PO 4 ) 2 f 3-2x (0≤x≤1) preparation method and use thereof. Background technique [0002] Since Exxon's first lithium-ion battery came out in the 1970s, lithium-ion batteries have attracted widespread attention due to their advantages such as small size, light weight, large specific capacity, long cycle life, and no memory effect. Its market demand is gradually increasing. However, lithium-ion batteries also have disadvantages such as low-temperature lithium precipitation, low conductivity, and easy sintering; in addition, the high raw material cost of lithium-ion batteries has also become a bottleneck restricting its rapid development. The chemical properties of sodium ions and lithium ions, which are also the main group I, have many similarities, and the raw material cost of sodium-ion batteries is low, the hal...

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Problems solved by technology

In 2010, Jiangqingzhao and others proposed the sol-gel method to prepare sodium vanadium phosphate. Although the process is simple, the heat treatment temperature is as high as 800°C

The sol-gel assisted two-stage high-temperature solid-phase method for preparing NaVPO proposed by patent CN103594716A 4 F, the process is complex, requires two calcinations, the calcination temperature is as high as 850°C, and has high requirements for the solubility of raw materials, making it difficult to achieve large-scale production

Patent CN102509789A proposes to use mechanical activation to assist one-step high-temperature solid-phase synthesis of Na 3 (VOxPO 4 ) 2 f 3-2x (0≤x≤1), although only one-step synthesis is required, but the ball milling time is long, the temperature of the high-temperature solid-state reaction process is as high as 450-1000 ° C, the roasting time is long, and the synthesis process is relatively complicated

Patent CN102306771A relates to the preparation method of sodium vanadium fluorophosphate positive electrode material, which adopts two calcinations, the calcination temperature is as high as 750°C, and the energy consumption is large, which will inevitably limit large-scale industrial application

Patent CN103022490A relates to a method for preparing sodium vanadium fluorophosphate in a short process, but the crystallization temperature of amorphous sodium vanadium phosphate is as high as 750°C, which consumes a lot of energy

Among the above methods for preparing sodium vanadium phosphate, high-temperature calcination is used without exception, and there are problems such as large energy consumption and difficult operation.

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