POSITIVE ELECTRODE ACTIVE MATERIAL FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, METHOD FOR PRODUCING SAME, POSITIVE ELECTRODE MIXTURE PASTE FOR NONAQUEOUS ELECTROLYTE SECONDARY BATTERIES, AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

摘要

The purpose of the present invention is to provide a positive electrode active material for nonaqueous electrolyte secondary batteries, which is capable of suppressing gelation of a positive electrode mixture paste during the production of a nonaqueous electrolyte secondary battery, thereby improving the stability of the paste. A positive electrode active material which contains secondary particles that are represented by general formula Li_sNi_1-x-y-zCo_xMn_yM_zO_2+α (wherein 0 ≤ x ≤ 0.35, 0 ≤ y ≤ 0.35, 0 ≤ z ≤ 0.10, 0.95 s 1.30, 0 ≤ α ≤ 0.2 and M represents at least one element selected from among V, Mg, Mo, Nb, Ti, W and Al), each one of said secondary particles being formed of aggregated primary particles, and wherein: at least a part of the surface of each primary particle is covered by a lithium boron compound; and the excess lithium hydroxide in the positive electrode active material as determined by a neutralization titration method is from 0.003% by mass to 0.5% by mass (inclusive) relative to the whole positive electrode active material.