COMPOSITE POSITIVE ELECTRODE MATERIAL WITH CORE-SHELL STRUCTURE FOR LITHIUM ION BATTERIES AND PREPARING METHOD THEREOF

摘要

A composite positive electrode material with a core-shell structure for a lithium ion battery consists of a core active material and a shell active material. The core active material is a lithium iron phosphate or a lithium manganate, and the shell active material is a composite lithium iron phosphate with carbon. The carbon is one or more of carbon nanotube, superfine conductive carbon black and amorphous carbon material. The composite positive electrode material includes from 65% to 99% core active material and from 1% to 35% shell active material, based on the total weight of the composite positive electrode material. The composite positive electrode material has stable property and excellent electrochemistry performance. The lithium ion battery made with the material has higher charge-discharge capacity, excellent cycle performance. It can be charged quickly and discharged at high rate. A preparing method for the composite positive electrode material is also provided.