Amorphous nano-spherical active iron phosphate hydrate and its preparation method and application

Abstract

The invention relates to an amorphous nanospherical active ferric phosphate hydrate, and a preparation method and an application thereof. The preparation method of the amorphous nanospherical active ferric phosphate hydrate comprises the following steps: 1, preparing a sustained release agent solution 1; 2, preparing a surfactant solution 2; 3, mixing the sustained release agent solution 1 with the surfactant solution 2 to obtain a solution A; 4, preparing a ferric nitrate nonahydrate solution; 5, dropwise adding the ferric nitrate nonahydrate solution into the solution A to prepare a solution B; 6, adding a phosphoric acid solution into the solution B to prepare a solution C; and 7, transferring the solution C into a polytetrafluoroethylene lined reaction kettle, carrying out a hydrothermal reaction, cooling the obtained reaction product, and carrying out separation and drying to obtain white powder which is the amorphous nanospherical active ferric phosphate hydrate. The method has the advantages of short reaction time, small and uniform product particle sizes, lithium iron phosphate obtained through the lithiation of the ferric phosphate hydrate prepared through the method has large tap density, and a battery product finally obtained through using the hydrate has good high-rate charge and discharge performances.

Description

technical field [0001] The invention relates to the technical field of cathode materials for lithium batteries, in particular to an amorphous nano-spherical active iron phosphate hydrate and a preparation method and application thereof. Background technique [0002] Lithium iron phosphate batteries are widely used because of their safety and stability, cheap raw materials and abundant reserves, but at the same time, their application range is affected to a certain extent due to their relatively low conductivity. In order to improve the electrical conductivity, it is usually necessary to synthesize nano-scale lithium iron phosphate, but after the material is made to the nano-scale, the tap density of the material is reduced, thereby reducing the energy density of the final battery product (that is, to improve the electrical conductivity rate, it is necessary to make the particle size of the material smaller, and making the particle size smaller will lead to a decrease in the ...

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Problems solved by technology

However, this method needs to be reacted for 2 days under the condition of 100°C water bath (or 2-8 hours under the condition of 150-200°C oil bath, the oil bath reaction is too fast, and the particle size uniformity of the obtained spherical ferric phosphate is slightly poor and the average particle size is larger than The water bath is slightly larger), and the average particle size of spherical ferric phosphate (ferric phosphate hydrate) formed by nanosheets in the above patent is 1.5 μm, and the long reaction time limits the industrial application of this method to a certain extent

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