POSITIVE ELECTRODE ACTIVE SUBSTANCE FOR LITHIUM SECONDARY BATTERY

摘要

The present invention relates to a positive electrode active substance for a lithium secondary battery, and provides a positive electrode active substance for a lithium secondary battery which is a lithium transition metal oxide of a layered crystalline structure, wherein said transition metal includes mixed transition metals of Ni, Mn and Co, the average oxidation number of the overall transition metal excluding lithium is larger than + 3, and the conditions of equation 1 (1.1 2+)/m(Mn4+) < 1) are satisfied. The positive electrode active substance according to the present invention, unlike the prior art, forms a more uniform and stable layered structure by controlling the oxidation number state of the transition metal in the transition metal oxide layer that forms the layered structure. Thus, it has such advantages that the overall electrochemical characteristics including battery capacity are enhanced, and the high rate charge/discharge characteristics are particularly excellent.