A PROCESS FOR PREPARING LITHIUM IRON PHOSPHORUS BASED COMPOSITE OXIDE CARBON COMPLEX AND A PROCESS FOR PREPARING COPRECIPITATE COMPRISING LITHIUM, IRON AND PHOSPHORUS

摘要

A method for preparing lithium, iron and phosphorus-based composite oxide carbon complex is provided to control the composition of Li, P and Fe easily, to obtain single phase LiFePO4 from the X-ray diffraction and to impart excellent battery capacity to the lithium secondary battery. A method for preparing lithium, iron and phosphorus-based composite oxide carbon complex comprises (S1) a step for obtaining the coprecipitate containing lithium, iron and phosphorus by contacting the solution(A) containing a lithium ion, a divalent iron ion and a phosphate ion with the solution(B) containing an alkali while controlling the pH to 5.5-9.5; (S2) a step for obtaining a plastic raw material mixture by mixing the coprecipitate and a conductive carbon material; and (S3) a step for obtaining a lithium, iron and phosphorus based composite oxide carbon complex by plasticizing the plastic raw material mixture under the inert gas atmosphere.