Preparation method of lithium manganese iron phosphate

Abstract

The invention discloses a preparation method of lithium manganese iron phosphate, wherein through a premixing unit and a stirring unit in a reaction kettle, the reaction is more uniform when an iron salt and a phosphate are mixed, the local concentration is reduced, a uniform iron phosphate precursor is prepared, and then the lithium manganese iron phosphate with uniform morphology is prepared by combining a wet method and a solid phase method. The conductivity of the lithium manganese iron phosphate is improved through carbon coating, and the cycle life, the first discharge capacity and the charge-discharge efficiency of the lithium manganese iron phosphate positive electrode material are improved.

Description

technical field [0001] The invention belongs to the field of new energy materials and relates to a preparation method of lithium manganese iron phosphate. Background technique [0002] With the enhancement of public awareness of environmental protection and the country's strong support in the field of new energy, lithium-ion batteries have gradually become widely used power storage devices. Lithium iron phosphate batteries are widely used in the field of new energy vehicles and energy storage due to their advantages such as good safety performance, long cycle life and low price, and because they do not contain precious metals and rare elements, they have abundant raw material reserves and relatively low environmental pollution. Small, lithium iron phosphate batteries are gradually favored by the market. However, the discharge voltage platform of lithium iron phosphate is low (~3.4V), and the compacted density is only 2.4g / cm 3 , leading to its low energy density, which lim...

AI Technical Summary

Problems solved by technology

However, since LiMnPO 4 The extremely poor conductivity of , is considered as an insulator, leading to the synthesis of LiMnPO capable of reversible charge and discharge 4 Very difficult, which limits its development and application

[0004] Lithium manganese iron phosphate LiMn x Fe 1-x PO 4 (04 Developed on the basis of modification, its preparation is difficult, although Fe 2+ The introduction of lithium manganese phosphate can improve the electrochemical performance of lithium manganese phosphate, but the range of improvement is limited, and it is difficult to fully exert the electrochemical performance of the material, which makes it difficult for the prepared lithium manganese iron phosphate to meet the application requirements.

Images