| abstract |
Provided are a lithium secondary battery having low internal resistance, high output, high capacity, and excellent charge / discharge cycle characteristics even under high temperature conditions, and a method for producing a positive electrode active material used therefor. As A positive electrode active material satisfies the general formula Li X Mn Y O Z- δ (wherein, (X / Y) = 0.48~0.52 , the relationship (δ / Z) ≦ 0.03 ), And ((V + B) / Mn) = 0.001 to 0.05 (molar ratio) with respect to manganese (Mn) constituting the lithium manganese composite oxide. A material containing vanadium (V) and / or boron (B) having a primary particle diameter of 1 μm or more, a crystallite size of 600 ° or more, and a lattice strain of 0.05% or less is characterized by being used. Lithium secondary battery. [Selection diagram] None |