LITHIUM IRON PHOSPHATE POSITIVE ELECTRODE ACTIVE MATERIAL MODIFIED BY GRAPHENE PREPARATION METHOD AND LITHIUM ION SECONDARY BATTERY THEREOF

摘要

The present invention relates to a graphene-modified iron phosphate lithium positive electrode active material, a method for producing the same, and a lithium ion secondary battery using the positive electrode active material. The positive electrode active material is prepared by dispersing graphene oxide and lithium iron phosphate in an aqueous solution, mixing them uniformly by stirring and ultrasonic treatment, and drying the mixture to obtain a lithium iron phosphate material having graphene or oxide graphene complex, Thereby obtaining a graphene-modified iron phosphate lithium positive active material. The lithium ion secondary battery using the positive electrode active material has a higher battery capacity, superior charge and discharge cycle performance, longer service life, and higher cycle stability than conventional lithium iron phosphate materials such as carbon coating and conductive polymer doping. This has high characteristics.