Preparation process of lithium iron phosphate material

Abstract

The invention discloses a preparation process of a lithium iron phosphate material. The process includes the following steps of: step 1: formulating lithium salt solution containing dispersant polyoxyethylene; step 2: putting ferric orthophosphate into the formulated lithium salt solution step by step, continuously stirring the mixed solution to fully react, mix and form colloidal solution in which the total mol rate of lithium to iron is 1.05-1.0; step 3: adding carbon source to the prepared colloidal solution with the adding amount being 20-40g / mol (Li), and drying after uniform mixing; and step 4: sintering the dried material of step 3 under the protection of nitrogen and preparing the finished product of lithium iron phosphate. After being ground and sieved, the lithium iron phosphate material produced by using the preparation process has the carbon content of 3.8-5.2%, compact density of 1.0-1.3g / mL and testing volume up to 150-160mA / h (0.2C). The volume is improved by over 15% compared with that of a solid ball milling method.

Description

technical field [0001] The invention relates to a lithium iron phosphate material, in particular to a preparation process of the lithium iron phosphate which can be used as a positive electrode material of a power lithium ion battery. Background technique [0002] Lithium iron phosphate material has the characteristics of good safety, excellent cycle performance, environmental friendliness, and wide source of raw materials. It is recognized as the preferred cathode material for the new generation of lithium-ion batteries, and has become the key research and development direction of major developed countries in the world today. Due to the complex preparation process of this material, high technical threshold and relatively slow industrialization speed, only a few companies in some developed countries have achieved mass production. [0003] There are usually two or more raw materials required for the preparation of lithium iron phosphate materials, and each material is a solid...

AI Technical Summary

Problems solved by technology

At present, most of the preparation methods of lithium iron phosphate adopt high-temperature solid-phase method, and the early mixing generally adopts solid ball milling or solid-alcohol ball milling. This kind of method can only ensure the mixing of various raw materials to the micron level, which not only affects the performance of lithium iron phosphate materials , which also limits its large-scale production

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