The present invention relates to a positive electrode additive of a lithium secondary battery which can be effectively applied to a high capacity battery accompanied by a use of a negative electrode having a high energy density, and a method for manufacturing the same. The positive electrode additive comprises a compound represented by chemical formula 1. The chemical formula 1 is represented by y(Li_2Ni_1-xM_xO_2)-z(Li_6Co_1-xM_xO_4). M is at least one element selected from a group consisting of P, B, F, W, Ti, and Zr.