Hot preparation technology of lithium iron phosphate solvent

Abstract

The invention provides a hot preparation technology of a lithium iron phosphate solvent. Water, an organic solvent and a lithium iron phosphate byproduct in wastewater are separated by adopting flash evaporation and centrifugal separation methods; part of the separated organic solvent participates into reaction as a raw material, so as to form an organic solvent circulating route; the other part of the separated organic solvent and the separated water are used as a solvent for countercurrent washing; a washing liquid after countercurrent washing is subjected to waste liquid treatment to separate the water and the organic solvent, so that a washing liquid circulating route is formed. Through comprehensive treatment and utilization on the waste liquid, the amount of the organic solvent and the production cost of lithium iron phosphate are greatly reduced.

Description

technical field [0001] The invention relates to the field of preparation of positive electrode active materials for lithium ion batteries, in particular to a solvothermal preparation process and preparation equipment for lithium iron phosphate. Background technique [0002] Lithium iron phosphate (LiFePO4, LFP), as an important cathode active material for lithium-ion batteries, has a wide range of applications in the energy storage and power battery markets. At present, there are two main types of process routes for the preparation of LFP, which are ferrous oxalate process (US A123 Systems, etc.), iron red process (US Valence Technology, etc.), iron phosphate process (Canada Phostech Lithium Company, US A123 Systems company, etc.) as the representative solid-phase preparation process and the solvothermal process route (Switzerland Clariant Chemicals, Korea Hanwa Chemical Company, etc.) as the representative liquid-phase preparation process. [0003] The solid phase preparat...

AI Technical Summary

Problems solved by technology

In the prior art, when recovering lithium resources and organic solvents, since lithium salts are dissolved in a mixed solvent composed of water and organic solvents, distillation is generally used to recover lithium salts and organic solvents in the waste liquid. However, distillation requires the use of Complex distillation equipment and high energy consumption of distillation lead to a substantial increase in the production cost of LEP; if the lithium resources and organic solvents in the waste liquid are not recovered, it will cause a lot of waste of lithium resources and organic solvents, which will also lead to The production cost of LEP has increased significantly

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