POSITIVE ELECTRODE MATERIAL FOR LITHIUM SECONDARY BATTERY, AND POSITIVE ELECTRODE AND LITHIUM SECONDARY BATTERY WHICH INCLUDE THE SAME

The present invention relates to a positive electrode material includes a first positive electrode active material, as large particles having a large average particle diameter, and a second positive electrode active material as small particles having a small average particle diameter, wherein the first positive electrode active material and the second positive electrode active material are each independently a lithium transition metal oxide having a molar ratio of nickel of 80 mol% or more relative to the total molar amount of transition metals in the lithium transition metal oxide, and the positive electrode material satisfies Equation (1): 0 < B − A / B × 100 ≤ 10 wherein, in Equation (1), A denotes a particle strength of the first positive electrode active material, and B denotes a particle strength of the second positive electrode active material.