Irreversible additive, positive electrode including the irreversible additive, and lithium secondary battery including the positive electrode

Abstract

Provided is a method of preparing an irreversible positive electrode additive for a secondary battery, which includes mixing LiO, NiO, and NHVOand performing thermal treatment to prepare a lithium nickel composite oxide represented by Chemical Formula 1 below, wherein the NHVOis mixed in an amount of 1.5 to 6.5 parts by weight with respect to a total of 100 parts by weight of the LiO, NiO, and NHVO.LiNiMVOA  [Chemical Formula 1] In Chemical Formula 1, Mis at least one selected from the group consisting of Cu, Mg, Pt, Al, Co, P, W, Zr, Nb, and B, A is at least one selected from the group consisting of F, S, Cl, and Br, and 0≤a≤0.2, 0≤b≤0.5, 0.01≤c≤0.065, and 0≤d≤0.2 are satisfied.