Preparation method of 3D micro/nano-structure spherical active iron phosphate

Abstract

The invention relates to a preparation method of 3D micro / nano-structure spherical active iron phosphate, which comprises the following steps: (1) preparing a surfactant solution; (2) preparing an iron nitrate nonahydrate solution; (3) dropwisely adding the iron nitrate nonahydrate solution into the surfactant solution to obtain a solution A; (4) weighing a H3PO4 solution, adding the phosphoric acid solution into the solution A, stirring and mixing for 30-240 minutes to obtain a clear transparent solution B; (5) reacting the obtained clear transparent solution B under the 80-100 DEG C water bath condition for 2-4 days or under the 150-200 DEG C oil bath condition for 2-8 hours; and (6) cooling, carrying out solid-liquid separation, washing, carrying out centrifugal separation to obtain a white precipitate, and drying the white precipitate at 80-110 DEG C. The iron phosphate material can be prepared into a LiFePO4 positive pole material after being lithiated, and has the advantages of favorable high-magnification charging / discharging performance and favorable tap density.

Description

technical field [0001] The invention relates to a method for preparing iron phosphate, in particular to a method for preparing spherical active iron phosphate with a 3D micro-nano structure. Background technique [0002] At present, the conductivity of lithium iron phosphate batteries is relatively low. In order to improve the conductivity, the material is made into nanoscale, but after the material is made into nanoscale, the tap density of the material is reduced, which reduces the power of the final battery product. . Moreover, currently in LiFePO 4 In the synthesis, in order to ensure product quality, expensive ferrous iron is often used (commonly used ferrous iron raw material: FeSO 4 ; FeCl 2 ; NH 4 FeSO 4 ), self-assembly of nanomaterials into micron materials, this method can improve performance to a certain extent, but it is often expensive, or the steps are complicated, or the final performance is not satisfactory, which has become an important reason for the ...

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Problems solved by technology

[0002] At present, the conductivity of lithium iron phosphate batteries is relatively low. In order to improve the conductivity, the material is made into nanoscale, but after the material is made into nanoscale, the tap density of the material is reduced, which reduces the power of the final battery product.

Moreover, currently in LiFePO 4 In the synthesis, in order to ensure product quality, expensive ferrous iron is often used (commonly used ferrous iron raw material: FeSO 4 ; FeCl 2 ; NH 4 FeSO 4 ), self-assembly of nanomaterials into micron materials, this method can improve performance to a certain extent, but it is often either expensive, or the steps are complicated, or the final performance is not satisfactory, which has become an important reason for the high price of the final product

Using the microwave method, the product performance is relatively poor and the equipment is expensive; the hydrothermal method needs to use a high-pressure hydrothermal kettle, the equipment is expensive, the synthesis steps are complicated, and the safety is poor, and accidents are easy to occur; the performance of the product prepared by the doping method is difficult to be simultaneously Good high rate charge and discharge performance and high tap density

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