Patent ID: 8821766

Claim:
Lithium manganate particles having a primary particle diameter of not less than 1 μm and an average particle diameter (D50) of secondary particles of 1 to 10 μm, which have a composition represented by the following chemical formula: Li1 +x Mn2 −x−y Y y O4 in which Y is at least one element selected from the group consisting of Al, Mg and Co; x and y satisfy 0.03≦x≦0.15 and 0.05≦y≦0.20, respectively, the Y element being uniformly dispersed within the respective particles, an intensity ratio of I(400)/I(111) thereof being not less than 33% and an intensity ratio of I(440)/I(111) thereof being not less than 16%; wherein when a section of the respective particles is subjected to EDX plane analysis by observing the particles using a scanning electron microscope equipped with an energy disperse type X-ray analyzer, the area of a white portion appearing on its micrograph which indicates the presence of the Y element is not less than 98% of a cross-sectional area of the respective particles and wherein a rate of change in BET specific surface area of the lithium manganate particles when applying a pressure of 1 ton/cm2 thereto is 0 to 10% based on a BET specific surface area of the particles before applying the pressure thereto.