Novel green lithium iron phosphate precursor as well as preparation method and application thereof

Abstract

The invention discloses a novel green lithium iron phosphate precursor as well as a preparation method and application thereof. The preparation method of the lithium iron phosphate precursor comprises the following steps: S1, reacting a mixture of an iron source and a phosphoric acid solution, and grinding after the reaction is completed to obtain a product A; reacting a mixture of an organic acid solution, a lithium source and a carbon source to obtain a product B after the reaction is completed; wherein the preparation sequence of the product A and the product B is not limited; and S2, grinding the mixture of the product A and the product B to obtain the lithium iron phosphate precursor. In the preparation process of the lithium iron phosphate precursor, the solid content can be greatly increased, the energy consumption of the subsequent process is small, and the preparation method is simple; the cost is low; and the prepared lithium iron phosphate precursor is extremely small in particle size and high in charge-discharge rate.

Description

technical field [0001] The invention provides a novel green lithium iron phosphate precursor and its preparation method and application. Background technique [0002] In recent decades, people around the world have actively developed lithium-ion power battery materials for use in transportation tools, such as electric vehicles and electric bicycles. The research on the power battery as vehicle power has become the main bottleneck in the development of power vehicles. Based on cost-effective considerations, lithium-ion batteries have great advantages. Lithium iron phosphate (LiFePO 4 ), also known as lithium iron phosphate, due to factors such as cycleability, price, safety, and specific energy, LiFePO 4 The material has many advantages such as stable structure, rich source of raw materials, environmental friendliness and low cost, 170mAh / g theoretical capacity, 3.5V stable discharge platform, etc., especially its safety performance and cycle life are unmatched by other ma...

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Problems solved by technology

[0009] The present invention aims to solve the problem in the prior art that when iron phosphate is used as raw material to prepare lithium iron phosphate, the solid content is relatively low, resulting in high process cost; when iron powder is used as raw material to prepare lithium iron phosphate, the solid content is difficult to control so that the reaction It can be carried out smoothly, and the energy consumption of the follow-up process can be reduced, and a new type of green lithium iron phosphate precursor and its preparation method and application are provided.

[0010] The inventors have found that when the iron source is used as the raw material in the preparation method of lithium iron phosphate in the prior art, for the smooth progress of the reaction, the solid content is inevitably too low, which leads to the defect of high energy consumption in the subsequent process ; And if the solid content is increased, it will cause the problem that the viscosity is too high and cannot be stirred

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