COMPLEX ACTIVE MATERIAL FOR CATHODE OF LITHIUM SECONDARY CELL, AND PREPARATION METHOD THEREOF

The present invention relates to a composite positive electrode active material for a lithium battery, and a producing method thereof. According to various embodiments of the present invention, the composite positive electrode active material can reduce polysulfide elution, can solve toxic problems of a reducing agent for reducing a graphene oxidizing agent, and has effects capable of preventing the decline in real utilization rate and cycle properties depending on using sulfur particles of a large particle diameter as well as improving graphene dispersibility. The producing method of the composite positive electrode active material for a lithium battery comprises a step of treating acid in (a) a precursor of a positive electrode active material selected from elements of a group 13 to a group 16 and transition elements in a periodic table, and (b) a solution comprising graphene oxide or dispersion. 본 발명은 리튬전지용 복합 양극 활물질 및 이의 제조방법에 관한 것이다. 본 발명의 여러 구현예에 따르면, 폴리설파이드 용출을 저감할 수 있고, 그래핀 산화제 환원을 위한 환원제 독성 문제를 해결할 수 있으며, 그래핀 분산성을 향상시킬 수 있을 뿐만 아니라, 큰 입경의 황 입자 사용에 따른 실이용율 및 사이클 특성의 저하를 막을 수 있는 효과를 달성할 수 있다.