Comprehensive modification method for synthesis of lithium iron phosphate

Abstract

The invention discloses a comprehensive modification method for the synthesis of lithium iron phosphate, comprising the following steps of: taking iron trioxide with a lower price as an iron source to replace expensive ferric oxalate and ferrous acetate; preparing a LiFePO4 / C material by an improved high-temperature solid phase method and combining synthesis, surface modification (carbon covering) and inner doping (phase doping) to finish the process. By utilizing the synthesis to be newly combined with the external modification and the inner doping, the cost is reduced. The battery does not contain any heavy metal and rare metal (a nickel-metal hydride battery needs the rare metal) and has no toxin (passing SGS (Societe Generale De Surveillance) authentication) and no pollution, so that the battery is the absolute green and environment-friendly battery. A lead-acid battery contains a lot of lead and secondary pollution to the environment is caused if the abandoned lead-acid battery is not properly processed; and no matter whether a lithium iron phosphate material is used for production or use, no pollution is caused, so that the battery is listed into an '863' National High-tech Development Plan during a;Twelfth Five-Year' period and is a project which is supported and encouraged to be developed by the country.

Description

technical field [0001] The invention relates to a comprehensive modification method for synthesizing lithium ferrous phosphate, which belongs to the technical field of lithium-ion battery materials, in particular positive electrode materials. Background technique [0002] Lithium-ion battery is a new generation of green high-energy battery. Since the commercialization of lithium-ion batteries, the research on cathode materials has always been a hot spot in the battery field. Commercial layered oxide LiCoO 2 : The positive electrode material has high capacity and long cycle life, but cobalt resources are scarce, expensive and toxic. LiNi x co 1-x o 2 , and other layered oxides and LiMn 2 o 4 The representative spinel-type cathode materials have been widely studied in the past 10 years, but their development is restricted due to their respective defects. Since the late 1990s, olivine-type lithium iron phosphate (LiFePO 4 ) The study of cathode materials has attracted ...

AI Technical Summary

Problems solved by technology

But LiFePO 4 The low electronic conductivity and slow lithium ion diffusion rate are not suitable for high current discharge, which affects the practical application of the material.

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