A method and application of low-cost preparation of lithium iron phosphate cathode material

Abstract

The invention relates to a method for preparing a lithium iron phosphate cathode material at low cost and an application of the lithium iron phosphate cathode material in a lithium ion battery. The preparation method comprises the following steps: firstly, introducing aqueous solutions of a lithium source and a phosphorus source into a spray drying cavity at a certain flow rate by an industrial spray drying method, and enabling the two substances to quickly react at relatively high surface energy at 140-220 DEG C, so as to prepare an iron phosphate material; then respectively preparing a lithium source solution, a reducing agent solution and an iron phosphate turbid liquid; under the conditions of normal temperature and constant-speed stirring, respectively injecting the lithium source solution and the reducing agent solution into a reaction kettle filled with iron phosphate turbid liquid, performing stirring for 2-3 hours at a constant speed, and centrifuging, washing and drying a product after the reaction is finished to obtain the lithium iron phosphate material. The synthesis process is carried out at 220 DEG C or below, and inert gas shielding is not needed; the whole processis operated in air, so the operation is safe, easy and convenient, the repeatability is good, the preparation cost of the target product is low, and the method has important significance in practicalapplication.

Description

technical field [0001] The invention belongs to the technical field of synthesis and application of inorganic materials, and in particular relates to a synthesis method and application of lithium iron phosphate. A method for synthesizing lithium iron phosphate in aqueous phase with iron as a raw material and its application in lithium ion batteries. Background technique [0002] Today, lithium-ion batteries are used more and more widely, and the requirements for their technology are also getting higher and higher. Among them, lithium iron phosphate, as its positive electrode material, has attracted more and more attention due to its excellent performance such as environmental protection, non-toxicity, and high capacity. Therefore, how to prepare lithium iron phosphate has become an important research topic for its industrialization. At present, the industrial production of lithium iron phosphate, in addition to the direct synthesis method, also has intermediate conversion,...

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Problems solved by technology

Therefore, the price of lithium iron phosphate material is very high

[0003] At present, the existing technology also has a process of preparing lithium iron phosphate by using low-temperature lithiated iron phosphate, but still uses organic solvents (such as absolute ethanol, etc.), and the mother liquor is generally difficult to recycle and reuse, resulting in waste

At the same time, the lithium source used in these preparation methods for lithiation, that is, most of the lithium-containing compounds are simple inorganic substances, and the solubility in organic solvents is not high. When preparing in large quantities, a large amount of solvents or even heating are required, resulting in energy consumption and increased costs.

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